HOW TO SET UP AND RESET AN MPPT CHARGE CONTROLLER (FLEXmax)

CASE STUDY: FLEXmax Series Charge Controllers




Table of Contents 

Introduction ..................................................................................................................... 7 

Features .................................................................................................................................................... 7 

Firmware ...................................................................................................................................... 7 

SoftKeys ....................................................................................................................................... 8 

Installation ....................................................................................................................... 9 

StandardsandRequirements......................................................................................................... 9 

Rapid Shutdown ................................................................................................................................... 9 

Grounding ............................................................................................................................................. 9 

DC / Battery-Related Installation Requirements .................................................................................. 9 

Dimensions ............................................................................................................................................ 10 

Mounting the Charge Controller ............................................................................................................ 11 

Wiring .................................................................................................................................................... 12 

Wire and Disconnect Sizing ............................................................................................................... 12 

FLEXmax 80 .................................................................................................................................. 12 

FLEXmax 60 .................................................................................................................................. 12 

Wiring Compartment........................................................................................................................... 13 

Operation ...................................................................................................................... 17 

 

Power Up Screens .................................................................................................................................. 17 

Version and/or Voltage Setting Screens ............................................................................................ 18 

Status Screen ..................................................................................................................................... 19 

End-of-Day Summary Screen ............................................................................................................ 20 

Navigating End-of-Day Screens & Data Logging ............................................................................... 21 

Modes of Operation ................................................................................................................................ 22 

Absorbing ........................................................................................................................................... 22 

Auto Start (Auto ReStart) ................................................................................................................... 23 

BatTmpErr .......................................................................................................................................... 23 

BatTooHot .......................................................................................................................................... 23 

Charged .............................................................................................................................................. 23 

EQ ...................................................................................................................................................... 23 

EQ Done ............................................................................................................................................. 23 

EX-Absorb .......................................................................................................................................... 24 

Floating ............................................................................................................................................... 24 

GT Mode ............................................................................................................................................. 24 

High V ........................................................................................................................................... 24 

Low Light or Snoozing ........................................................................................................................ 24 

MPPT Bulk .......................................................................................................................................... 24 

MPPT Float ......................................................................................................................................... 25 

MPPT EQ ........................................................................................................................................... 25 

New  V ........................................................................................................................................... 25 

OvrCurrent .......................................................................................................................................... 25 

Over Temp .......................................................................................................................................... 25 

Re-Cal ................................................................................................................................................ 25 

Sleeping .............................................................................................................................................. 25 

Sys Error ............................................................................................................................................. 26 

Tracking .............................................................................................................................................. 26 

Unloaded ............................................................................................................................................ 26 

Wakeup .............................................................................................................................................. 26 

Zzzzz... ............................................................................................................................................... 26 

Table of Contents 

 

Initial Operation ..................................................................................................................................... 27 

Changing the Settings on the FLEXmax .............................................................................................. 27 

Accessing the Main Menu .................................................................................................................. 27 

Main Menu Map .................................................................................................................................. 28 

Charger Screen .............................................................................................................................. 29 

Aux Screens ................................................................................................................................... 30 

AUX MODE Screen Navigation ..................................................................................................... 32 

Vent Fan (AUX Mode) ............................................................................................................... 33 

PV Trigger (AUX Mode) ............................................................................................................. 34 

Error Output (AUX Mode) .......................................................................................................... 35 

Night Light (AUX Mode) ............................................................................................................. 36 

Float (AUX Mode) ...................................................................................................................... 37 

Diversion (AUX Mode) ............................................................................................................... 38 

Low Battery Disconnect (AUX Mode) ........................................................................................ 43 

Remote (AUX Mode) ................................................................................................................. 44 

Backlight ......................................................................................................................................... 44 

EQ – Battery Equalize .................................................................................................................... 45 

Misc Screen ................................................................................................................................... 47 

Advanced Menu ............................................................................................................................. 49 

Snooze Mode (Advanced Menu) ............................................................................................... 49 

Wakeup Mode  (Advanced Menu) ............................................................................................. 50 

MPPT Mode (Advanced Menu) ................................................................................................. 50 

Absorb Time Limits (Advanced Menu) ...................................................................................... 52 

Absorb End Amps (Advanced Menu) ........................................................................................ 52 

Rebulk Voltage (Advanced Menu) ............................................................................................. 53 

Vbatt Calibration (Advanced Menu) ........................................................................................... 53 

RTS Compensation (Advanced Menu) ...................................................................................... 53 

Auto ReStart (Advanced Menu) ................................................................................................. 55 

Aux Polarity (Advanced Menu) .................................................................................................. 56 

Reset to Defaults? ..................................................................................................................... 56 

Logging .......................................................................................................................................... 57 

Stats ............................................................................................................................................... 58 

Viewing the Firmware Revision .......................................................................................................... 59 

Extended Play Mode .......................................................................................................................... 59 

Rebooting the FLEXmax .................................................................................................................... 60 

MATE3-class System Display  and Controller ............................................................... 61 

Display and LED Status Indicators ......................................................................................................... 61 

Charge Controller Soft Key ............................................................................................................ 62 

DataLog Screen ......................................................................................................................... 63 

Graph Screens ........................................................................................................................... 64 

Menu Structure in the MATE3 and MATE3s ........................................................................................ 65 

Charge Controller Settings ................................................................................................................... 66 

Charger ............................................................................................................................................... 66 

MPPT .................................................................................................................................................. 66 

Temperature Compensation ............................................................................................................... 67 

Battery Equalize ................................................................................................................................. 67 

Grid-Tie Mode ..................................................................................................................................... 67 

Auxiliary Output (Charge Controller) .................................................................................................. 68 

Aux Modes for the Charge Controller ............................................................................................ 68 

Restart Mode .................................................................................................................................. 69 

Calibrate ......................................................................................................................................... 70 

Reset Charge Controller to Factory Defaults ................................................................................. 70 

Device Data Logs ................................................................................................................................. 71 

Saving Data Logs for the FLEXmax Controller .................................................................................. 71 

Data Log File Format ................................................................................................................. 72 

MATE-Class System Display and Controller ................................................................. 73 

Summary Screens .................................................................................................................................. 73 

Status Screens ....................................................................................................................................... 74 

MODE Screens ................................................................................................................................... 74 

METER Screens ................................................................................................................................. 75 

SETPT Screens .................................................................................................................................. 76 

LOG Screens ...................................................................................................................................... 77 

STAT Screens .................................................................................................................................... 78 

Advanced Menus .................................................................................................................................... 79 

Accessing the Advanced Menus ........................................................................................................ 79 

CHGR Menu ....................................................................................................................................... 80 

CC ADVANCED Menu ....................................................................................................................... 81 

EQ Menu ............................................................................................................................................ 82 

AUX Menu .......................................................................................................................................... 83 

MATE and MATE2 FLEXmax Menu Maps ......................................................................................... 84 

STATUS Menu Map ........................................................................................................................... 84 

Advanced Menu Map ......................................................................................................................... 86 

Menu Maps for the FLEXmax ........................................................................................ 89 

Troubleshooting ............................................................................................................ 93 

Specifications ................................................................................................................ 95 

Electrical and Mechanical Specifications .............................................................................................. 95 

Firmware Revision ................................................................................................................................ 95 

Regulatory Specifications ..................................................................................................................... 95 

Default Settings and Ranges .................................................................................................................. 96 

Applications ................................................................................................................... 97 

Maximum Power Point Tracking ........................................................................................................... 97 

Three-Stage Battery Charging .............................................................................................................. 98 

BULK .................................................................................................................................................. 98 

ABSORBING ...................................................................................................................................... 99 

FLOAT ................................................................................................................................................ 99 

Battery Temperature Compensation .................................................................................................. 99 

Array Design ......................................................................................................................................... 100 

Sizing Guidelines .............................................................................................................................. 100 

Open Circuit Voltage (V) ................................................................................................................ 100 

Weather Conditions ...................................................................................................................... 100 

Maximum-Power Voltage (V) ........................................................................................................ 101 

Standard vs. Australian Default Settings ............................................................................................. 101 

Hydroelectric and Fuel Cell Applications Performance Optimization ............................................... 102 

Auto Track Mode .............................................................................................................................. 102 

U-Pick Mode ..................................................................................................................................... 102 

Grid-Interactive Settings ..................................................................................................................... 104 

FLEXmax Efficiency vs. Input Power ................................................................................................ 104 

Definitions ........................................................................................................................................... 105 

Index ........................................................................................................................... 107 

Table of Contents 

 

List of Tables 

Table 1  Battery Voltage and Charge Timer .......................................................................................... 23 

Table 2  Aux Mode Functions ................................................................................................................ 30 

Table 3  Regulatory Specifications for All Models ............................................................................... 95 

Table 4  FLEXmax Settings ................................................................................................................... 96 

Table 5  Maximum PV Input Wattage per Charge Controller   .......................................................... 100 

Table 6  Default Settings Standard vs. Australian ............................................................................... 101 

Table 7  Terms and Definitions ............................................................................................................ 105 

IMPORTANT:   

Introduction 

This manual provides safety guidelines and installation information for the

FLEXmax Series Charge Controllers. It does not provide information about

specific brands of PV modules and supplies limited information on batteries.   

Contact the supplier or manufacturer of the PV modules or batteries for

additional information. 

Thank you for purchasing a FLEXmax Series Charge Controller (CC).  These charge controllers

offer an efficient, safe, multi-stage recharging process that prolongs battery life and assures

peak performance from a PV array.   

Each charge controller is designed to seamlessly integrate with other OutBack components and

can be remotely monitored and configured (up to 1000 feet or 300 meters away) using the

optional OutBack Power system displays. 

Features 

The FLEXmax Charge Controllers use continuous Maximum Power Point Tracking (MPPT),

which seeks out the maximum power available from a PV array and uses it to recharge the

batteries.  Without this feature, the PV array does not operate at the ideal voltage and can only

operate at the level of the battery voltage itself.  (See page 97 for a description of MPPT.)  Each

charge controller continuously tracks the array’s maximum operating power.   

oThe FLEXmax Series has two models available: 

o FLEXmax 80:  80 amps maximum continuous output current (up to 40°C without thermal derating) 

o FLEXmax 60:  60 amps maximum continuous output current (up to 40°C without thermal derating)  

Both models have the following features: 

o Supports 12, 24, 36, 48, and 60 Vdc battery voltages

o Backlit LCD display screen with 80 characters (4 lines, 20 characters per line)

o Last 128 days of operational data are logged for review

o Voltage step-down capability allows a higher PV array voltage configuration

o Manual and auto-equalize cycle 

Firmware 

This manual covers FLEXmax firmware revision 003.003.000 or higher. 


Introduction  

Soft Keys 

Figure 1 Charge Controller Features  

Four “soft” keys are located directly below the LCD.  The functions of the soft keys will vary

depending on the location of the user within the menu structure.  Some soft keys will be used for

navigation.  Some soft keys will be used for programming.   

Softkey functions are identified by text on the LCD screen directly above the key (e.g., EXIT). 

In this manual, soft keys will be identified by brackets (for example, <EXIT>).  Not every soft 

key may be used on some screens. 

FLEXmax 80 FLEXmax 60 

Soft Key Buttons

LCD Screen 

Soft Keys 

Main Menu 

Charger  Aux   Light

  EQ    Misc  Advanced

  Logging    Stats 

 EXIT          GO 

SK1 SK2 SK3 SK4 

Figure 2 Soft Keys  

LCD 

Soft Key Commands

(<EXIT>, <GO> etc.) 

Standards and Requirements 

Installation 

All installations must comply with national and local electrical codes; professional installation 

is recommended.  


IMPORTANT:   

The charge controller is designed for indoor installation or installation inside a weatherproof

enclosure.  It must not be exposed to rain and should be installed out of direct sunlight. 

Rapid Shutdown   

The FLEXmax 60 and FLEXmax 80 charge controllers are not to be installed on controlled

conductors of a PV Rapid Shutdown System (PVRSS).  Controlled conductors are defined by

the 2017 National Electrical Code and may be different from local requirements.  

Grounding 

This product is intended to be installed as part of a permanently grounded electrical system. 

 oThe FLEXmax equipment ground is marked with this symbol:   

The following important restrictions apply unless superseded by local or national codes: 

o The negative battery conductor should be bonded to the grounding system at only one point in the

system.  If a GFDI is present, the battery negative and ground are not bonded together directly but

are connected together by the GFDI device when it is on.  All negative conductor connections must

be kept separate from the grounding conductor connections. 

 oThe FLEXmax controller is not intended to be wired into a positive-ground configuration.  However,

certain telecom applications may require this configuration.  If a positive-ground system is necessary,

consult www.outbackpower.com/forum/, where this subject has been discussed extensively. 

o If damaged or malfunctioning, the FLEXmax should only be disassembled and repaired by a qualified

service center.  Please contact the local renewable energy dealer/installer for assistance.  Incorrect

reassembly risks malfunction, electric shock or fire. 

o DC / Battery-Related Installation Requirements 

o Shut off all DC circuit breakers before connecting any wiring.

o Torque all the FLEXmax wire lugs and ground terminals to 4 Nm (35 in-lb).

o Copper wiring must be rated at 75°C or higher.

o Use up to 35 mm

2

 (2 AWG) to reduce losses and ensure the highest performance of the FLEXmax. 

o Smaller cables can reduce performance and possibly damage the unit. 

 Run positive and negative cables side by side.  

 Keep cables together as much as possible to allow the inductive currents to cancel.

o Ensure paired cables pass through the same knockout and conduit fittings.  

 DC battery overcurrent protection must be used as part of the installation.  OutBack offers both circuits

breakers and fuses for overcurrent protection. 

 

Installation 

Dimensions  

FLEXmax 80 

Controller 

FLEXmax 60

Controller 

 

 

5.75” 

(14.6 cm) 

16.25” (41.3 cm) 

13.5” (34.3 cm) 

Figure 3 FLEXmax 80 and FLEXmax 60 Dimensions  

4.0”

(10.2 cm) 

Mounting the Charge Controller  

 

Holes for 

#10 x 3/8”

sheet metal 

Bushing 


IMPORTANT:   

Install the FLEXmax in an upright position out of direct sunlight. 

DC

Enclosure 

Insert screws

through lower

holes inside

the charge

controller  

Charge Controller

(front view) 

Lock Nut Lock Nut 

Conduit

Nipple 

Figure 4 Mounting the Charge Controller  

 

Installation

 

The FLEXmax is designed to attach

directly to OutBack’s FLEXware 500 DC

and FLEXware 1000 DC enclosures

(FLEXware 500 shown) or attach to its

own charge controller brackets (FW-CCB,

FW-CCB2, and FW-CCB2T).  

 

Mounting directly to a FLEXware

DC enclosure: 

1. Remove the fan cover and bottom

cover from the FLEXmax. 

2. Insert a #10 × ⅜” sheet metal screw

in the top hole on the side of the DC

enclosure. This will act as a hanging

screw for the keyhole slot at the top

center of the FLEXmax. 

3. Hang the FLEXmax on the top 

screw and line up its bottom two

screw holes with the holes on 

the enclosure. 

4. Insert a #10 × ⅜” sheet metal screw

through each hole and tighten against

the enclosure (screws are included

with each DC enclosure). 

5. Keep the cover off until the wiring 

is completed. 

The conduit nipple assembly creates a

sealed connection from the FLEXmax to

the enclosure. 


 

Mounting to Plywood

Use 1-5/8” wood screws to secure the 

FLEXmax at the top slotted holes and

another interior lower holes as needed, 

making sure the unit is straight and level. 

 

Installation 

Wiring 

This section provides instructions on installing PV array wiring into the FLEXmax controller. 

See page 100 for more notes on PV array sizing and operation. 

Wire and Disconnect Sizing 


IMPORTANT:   

FLEXmax 80 

 Wire sizes must comply with local and national codes.  Input conductors and circuit

breakers must be rated at 1.56 times the short-circuit current of the PV array (according

to NEC).  OutBack 100% duty continuous circuit breakers only need to be rated at 1.25

times the short-circuit current. 

 Copper wiring must be rated at 75°C or higher.

 Use up to #2 AWG (33.6 mm2) to reduce losses and ensure high performance of the

FLEXmax (smaller cables can reduce performance and possibly damage the unit). 

o The output current limit of the FLEXmax 80 is 80 amps.

o Install OutBack PNL-80-DC circuit breakers for disconnect and overcurrent protection

o Use a minimum of #4 AWG (25 mm2) wire for the output between the FLEXmax 80 and the battery

bus bar conductors. 

o The largest PV array must have a rated short-circuit current of 64 amps or less under STC 

(Standard Test Conditions). 

o Torque all the FLEXmax wire lugs and ground terminals to 4 Nm (35 in-lb). 

FLEXmax 60 

 o The output current limit of the FLEXmax 60 is 60 amps.

o Install OutBack PNL-60-AC/DC or PNL-80-DC circuit breakers for disconnect and overcurrent 

protection.

o Use a minimum of #6 AWG (16 mm2) wire for the output between the FLEXmax 60 and the battery

bus bar conductors. 

 o The largest PV array must have a rated short-circuit current of 48 amps or less under STC 

(Standard Test Conditions). 

o Torque all the FLEXmax wire lugs and ground terminals to 4 Nm (35 in-lb). 

Please refer to the NEC and other electrical codes for recommendations on PV array cable

sizing and recommended length and ampacity. 


Wiring Compartment 


WARNING:  Shock Hazard 

Make sure all DC circuit breakers are OFF (open) BEFORE making any wiring connections. 

Use a DVM to check for voltage on all wires. 

The PV– (negative) and BAT– (negative) terminals are connected internally.  Only one negative

wire may be needed to connect to the (–) wire lugs if the PV– and BAT– conductors are bonded

at the negative bus bar.  

Auxiliary Output

(AUX) Terminals 

Battery Remote

Temp Sensor 

(RTS) RJ11 port 

PV+ PV– BAT– BAT+ 


CAUTION:  Equipment Damage 

Each FLEXmax requires its own PV array.  DO NOT PARALLEL FLEXmax PV+ and PV-

TERMINALS ON THE SAME ARRAY! 

An optional battery Remote Temperature Sensor (RTS) is recommended for accurate

battery charging.  

o Only one RTS is needed for multiple OutBack inverter/chargers and charge controller units when the

system includes an OutBack HUB and a system display.  

 o When one RTS is used, it must be connected to the component plugged into PORT1 of the HUB. 


Installation

 

Wire terminals 

o Use up to 35 mm


(#2 AWG) wire  

o Torque to 4 Nm (35 in-lb)

MATE/HUB 

RJ45 port 

Screw holes for mounting

the charge controller 

Chassis/Equipment

Ground Lug 

Operation 

Operation of this unit consists of monitoring screens and programming screens.  The majority of

programming screens are accessed using the main menu.  See page 27.  

Power Up Screens     

 


IMPORTANT:   

 The default settings of the FLEXmax are for a 12 Vdc battery bank.  Change the setting

after powering up if a different battery voltage is used. 

 Once set, the FLEXmax retains the nominal voltage setting.  Following any type of

shutdown or disconnect, it will return to operate automatically. 

 The PV array voltage is automatically detected.  The PV array voltage must never

exceed 150 V

.

 Restore the FLEXmax to factory default settings (see page 56) and reset the nominal 

voltage any time the system is substantially revised or the controller is relocated. 

The FLEXmax uses power from the battery bank to operate.  The battery voltage must be at

least 10.5 volts or higher to power up the FLEXmax.  When battery power is detected, the

FLEXmax will go through a series of power-up screens.  

Power Up Screen 

OutBack            12V

        Power

               Systems

Charge Controller - AU 

System Voltage 

On Australian

versions only 

To change version settings:

While turning on the circuit breaker, press  

and hold the first and third soft keys to bring 

up the Select Version screen.  Changing the  

version settings require entering a password.   

NOTE:  This will reset the FLEXmax to default settings. 

It may be necessary to re-enter previous settings. 

To change the system password:     

1. Press <NEXT> or <SEL> when the Select 

Version screen appears on power-up.  

This will open the PASSWORD screen. 

2. Press <–>  or <+> to reduce the number from

150 to 141. 

3. Press <ENTRA> or <ENTER> to enter the

new password.   

To power up the charge controller:

1. Ensure PV and battery circuit breakers are OFF.  

2. Turn ON the battery circuit breaker only. 

 The FLEXmax will show the system battery 

voltage in the upper right corner of the screen. 

If the screen reads Low Battery Voltage, see

the Troubleshooting section on page 93. 

 If the Australian version was previously

selected, AU will be displayed in the lower right

corner of the screen. 

OutBack            12V

        Power 

               Systems

Charge Controller - AU 

       PASSWORD

      CONTRASENA

       ***150***

ENTRA   -    +   ENTER 

Figure 9 Powering up the FLEXmax 

Continued on next page... 

Select Version offers two types of options.  The English (default) or Spanish selections offer

standardized charge settings in two languages.  Selecting Australian leaves the menus in 

English, but changes the charging parameters.  (For details, see Table 6 on page 101.) 

PASSWORD

Screen Operation Version and/or Voltage Setting Screens 

Once the password has been entered, the display will return to the Select Version screen. 

 

Select Version 

     Select Version

    Elija la Version

        English

 NEXT ENTER ENTRA SEL 

or 

Select Version 

     Select Version

    Elija la Version

        English

 NEXT ENTER ENTRA SEL 

or 

Confirmation Screen 

     Are you sure?


        English

 NO               YES 

SYSTEM VOLTAGE Screen 

    SYSTEM VOLTAGE

12  24  36  48  60

^^  

          ENTER 

Verification Screen 

     Are you sure?

12  24  36  48  60

^^  

 NO                YES 

Status Screen 

In    11.6V   0.0 A

Out   13.8V   0.0 A

    0.000 kW  0.0 kWH

AUX: OFF      Sleeping 

To change the version:

1. Press <NEXT> or <SEL> to cycle through the version choices 



 

of: 

 English,

 Australian,  or

 Espanola.  

2. When the desired version is displayed, press <ENTER> or

<ENTRA> to proceed to the confirmation screen. 

 

3. Press <YES> to confirm the selection.  

The SYSTEM VOLTAGE screen appears next.

The FLEXmax automatically detects the system’s battery voltage and

indicates it by placing two ^^ symbols below the value.   

o If the value indicated is correct, press <ENTER>.

o If the value indicated is not correct for the present system, 

press <> to move the ^^ to below the correct voltage.

o Press <YES> to confirm the selection. 

The Status screen is the last screen to be displayed after startup. 

The soft keys below the Status screen navigate to the main menu and

the End-of-Day summary screen.  See page 19 for details on the Status screen.    

The status screen displays system information.  See page 20 for detailed information of the

different modes of operation.  

The optional OutBack system display shows CC (Charge Controller) status screens for

convenient distant viewing from the installation location.  See page 61 for the FLEXmax screens

displayed on the MATE3 or MATE3s.  Please see pages 73 to 85 to view the FLEXmax screens

displayed on the MATE or MATE2.   

 

Status Screen 

In    11.6V   0.0 A

Out   13.8V   0.0 A

    0.000 kW  0.0 kWH

AUX: OFF      Sleeping 

In    11.6V   0.0 A

Out   13.8V   0.0 A

    0.000 kW  0.0 kWH

AUX: OFF      Sleeping 

In    11.6V   0.0 A

Out   13.8V   0.0 A

    0.000 kW  0.0 kWH

AUX: OFF      Sleeping 

In    11.6V   0.0 A

Out   13.8V   0.0 A

    0.000 kW  0.0 kWH

AUX: OFF      Sleeping 

In    11.6V   0.0 A

Out   13.8V   0.0 A

    0.000 kW  0.0 kWH

AUX: OFF      Sleeping 

In    11.6V   0.0 A

Out   13.8V   0.0 A

    0.000 kW  0.0 kWH

AUX: OFF      Sleeping 

In    11.6V   0.0 A

Out   13.8V   0.0 A

    0.000 kW  0.0 kWH

AUX: OFF      Sleeping 

In    11.6V   0.0 A

Out   13.8V   0.0 A

    0.000 kW  0.0 kWH

AUX: OFF      Sleeping 

PV Input Voltage 

PV Input Current 

Battery Voltage

Output Current 

Instantaneous

Kilowatts 

Daily Accumulated

Kilowatt-hours 

AUX Status

(ON or OFF) 

Mode of Operation

See page 22 

Operation

The PV voltage will slowly rise to the battery voltage level even when the PV breaker is off — this is normal as the PV capacitors charge up. 

Navigation 

Status Screen 

In    11.6V   0.0 A

Out   13.8V   0.0 A

    0.000 kW  0.0 kWH

AUX: OFF      Sleeping 

Pressing the first soft key (SK1)

opens the main menu screen. 

Status Screen 

In    11.6V   0.0 A

Out   13.8V   0.0 A

    0.000 kW  0.0 kWH

AUX: OFF      Sleeping 

Pressing SK2 opens the end-of-day

summary menu and logging. 

 

Operation

 

End-of-Day Summary Screen 

The end-of-day summary screen appears after one hour of continuous Sleeping (see page 25). 

This screen can be opened any time by pressing the second soft key while in the status screen,

providing a summary up to that point.  

NOTE: 

When finished viewing the end-of-day

screen(s), be sure to return the display

to the status screen.  Otherwise, it will

not reset the counters when the sun

rises the next morning.  The values will

continue to accumulate. 

End-of-Day Screen 

Today  000Ah   00.0kWH

011Vp  00.0Ap  0.00kWp

MAX 14.7 V   ABS 01:00

MIN 14.6 V   FLT 00:00 

Today  000Ah   00.0kWH

011Vp  00.0Ap  0.00kWp

MAX 14.7 V   ABS 01:00

MIN 14.6 V   FLT 00:00 

Today  000Ah   00.0kWH

011Vp  00.0Ap  0.00kWp

MAX 14.7 V   ABS 01:00

MIN 14.6 V   FLT 00:00 

Today  000Ah   00.0kWH

011Vp  00.0Ap  0.00kWp

MAX 14.7 V   ABS 01:00

MIN 14.6 V   FLT 00:00 

Today  000Ah   00.0kWH

011Vp  00.0Ap  0.00kWp

MAX 14.7 V   ABS 01:00

MIN 14.6 V   FLT 00:00 

Today  000Ah   00.0kWH

011Vp  00.0Ap  0.00kWp

MAX 14.7 V   ABS 01:00

MIN 14.6 V   FLT 00:00 

Today  000Ah   00.0kWH

011Vp  00.0Ap  0.00kWp

MAX 14.7 V   ABS 01:00

MIN 14.6 V   FLT 00:00 

Today  000Ah   00.0kWH

011Vp  00.0Ap  0.00kWp

MAX 14.7 V   ABS 01:00

MIN 14.6 V   FLT 00:00 

Today  000Ah   00.0kWH

011Vp  00.0Ap  0.00kWp

MAX 14.7 V   ABS 01:00

MIN 14.6 V   FLT 00:00 

Today  000Ah   00.0kWH

011Vp  00.0Ap  0.00kWp

MAX 14.7 V   ABS 01:00

MIN 14.6 V   FLT 00:00 

Day (up to 128 days) 

Accumulated

Amp-hours 

Accumulated kWh

Total Power 

Peak Input Voltage 

Peak Output Current 

Peak Output

Power in 

Maximum Battery

Voltage Obtained 

Accumulated

Absorb Time 

Minimum Battery

Voltage Obtained 

Accumulated

Float Time 

Figure 12 End-of-Day Summary Screen 

Navigating End-of-Day Screens & Data Logging  

Status Screen End-of-Day Screen 

In    11.6V   0.0 A

Out   13.8V   0.0 A

    0.000 kW  0.0 kWH

AUX: OFF      Sleeping 

Today  000Ah   00.0kWH

011Vp  00.0Ap  0.00kWp

MAX 14.7 V   ABS 01:00

MIN 14.6 V   FLT 00:00 

Press SK2 to open the

CLEAR LOG screen. 

Today  000Ah   00.0kWH

011Vp  00.0Ap  0.00kWp

MAX 14.7 V   ABS 01:00

MIN 14.6 V   FLT 00:00 

Press SK3 to open the previous day’s

summary screen.  Continuing to press

this soft key will cycle back through

the last 128 daily summary screens. 

Today  000Ah   00.0kWH

011Vp  00.0Ap  0.00kWp

MAX 14.7 V   ABS 01:00

MIN 14.6 V   FLT 00:00 

Pressing SK4 will bring

up the summary for the

128

th

Pressing the second soft key

(SK2) opens the end-of-day

summary menu/logging. 

 day back. 

Today  000Ah   00.0kWH

011Vp  00.0Ap  0.00kWp

MAX 14.7 V   ABS 01:00

MIN 14.6 V   FLT 00:00 

CLEAR LOG Screen

End-of-Day Screen 

End-of-Day Screen 

End-of-Day 

The daily statistics or the accumulated

statistics are stored on the charge

controller's static memory.  A new log “day”

begins when the controller enters Wakeup. 

(See page 26.)  Logs accumulate for up to

128 days.  See pages 77 and 78 for details. 

CLEAR LOG

BACK  TOTAL  DAILY 

Figure 13 Navigating the End-of-Day Summary Screen 


Operation

 

Press SK1 to return to the

status screen. 

OR 


Are you sure? 


 NO               YES 

OR 

End-of-Day Screen 

Today  000Ah   00.0kWH

011Vp  00.0Ap  0.00kWp

MAX 14.7 V   ABS 01:00

MIN 14.6 V   FLT 00:00 

Press SK1 to return to the

status screen. 

This data log can be downloaded to an SD card. 

A MATE3-class system display is required 

for this download.  See page 71 for details on 

this function.   

 

  

 

Operation

 

Modes of Operation   

The FLEXmax has 25 different modes that will display on the status screen.  These messages

will vary with function.  The FLEXmax modes consist of various charging stages, equalization,

various reasons for stopping charging, and certain specialized operating modes. 

The amount of time required before starting operation is dependent on the module type,

ambient temperature, and the amount of sunlight directly on the PV array.  Normally, the charge

controller starts operation in the morning within a few minutes of the PV array being exposed to 

direct sunlight. 

The FLEXmax modes of operation will change occasionally during the day based on the PV

array output and the battery system state of charge.  The FLEXmax operating modes are

displayed at the bottom right-hand corner of the status screen.  See Figure 11.  

Figure 14 shows an example of the various stages of operation during battery charging and the

messages shown during each stage.  Battery charging is described in detail on page 98.  

Absorbing  

The FLEXmax is in the Absorbing stage of a three-stage cycle, regulating the battery voltage at

the Absorbing voltage set point.  While the batteries are held at this voltage, the ChgT counter

in the Misc menu counts up from zero toward the user-defined Absorb Time Limit.  (See

pages 47 and 52.)  The charger will exit this stage and enter the Float stage if the ChgT timer 

reaches the time limit, or if the Absorb End Amps setting is reached.  

If the battery voltage drops below the Absorbing voltage (see page 29), the FLEXmax reverts 

back to the Bulk charge stage and displays MPPT Bulk as shown on page 24.  The ChgT

counter will begin counting back toward zero.  Lower voltages will cause the timer to subtract 

minutes at a faster rate, as shown in Table 1 on page 23. 


Table 1 Battery Voltage and Charge Timer 

Battery Voltage ChgT (Charge Timer) Activity/Display 

  12.4 V, 24.8 V, 37.2 V, 49.6 V, or 62.0 V,

and less than the Absorbing voltage 

No change. 

<12.4 V, 24.8 V, 37.2 V, 49.6 V, or 62.0 V

For every minute elapsed, 1 minute is subtracted 

from the timer.

<12.0 V, 24.0 V, 36.0 V, 48.0 V, or 60.0 V 

For every minute elapsed, 2 minutes is subtracted

from the timer. 

< 11.6 V, 23.2 V, 34.8 V, 46.6 V, or 58.0 V

For every minute elapsed, 4 minutes is subtracted 

Auto Start (Auto ReStart)  

from the timer. 

 

This setting allows the user to choose between continuous MPP tracking or occasional restarts

of the sweeping process.  A restart means the controller abandons the existing MPP and

“re-sweeps”, or begins gathering new power point data.  See page 55 for more information. 

o Mode 1:  Once every 1.5 hours in the Bulk charging stage 

o Mode 2:  Once every 1.5 hours in the Bulk, Absorbing, and Float recharging stages

o Mode 0:  Auto ReStart is disabled completely.  It will continuously track the maximum power point 

without starting over. 

NOTE: If enabled, AutoStart also occurs during the MPPT EQ cycle.  See page 25. 

BatTmpErr   

The battery temperature sensor is shorted or damaged.  Charging will not be temperature

compensated.  (The cooling fan will continuously operate.)  See RTS compensation on page 53. 

BatTooHot   

The battery temperature sensor has detected a battery temperature of over 50°C.  The

FLEXmax will stop charging the battery and wait for the battery to cool below 50°C. 

Charged   

There is an external DC source other than PV keeping the battery above the Float voltage set

point (see page 29).  The FLEXmax will stop charging because it is not needed.  The display

may also appear when the cycle is transitioning from Absorbing (upper target voltage) to 

Floating (lower voltage). 

EQ 

  

The charger is in a cycle of equalization.  (See page 45.)  This is the time elapsed in hours and

minutes since the BATTERY EQUALIZE VOLTS set point was met.   

If this set point is not maintained, the controller will revert back to MPPT EQ.  (See page 25.) 

The EQ timer will pause until the batteries are regulated at the BATTERY EQUALIZE VOLTS

set point again.  The paused time can be viewed in the End-of-day Summary (see page 20).  

EQ Done  

Once the set EQ time (between 1 and 7 hours) has successfully completed, the FLEXmax will

transition to Float stage.  EQ Done will be displayed either until a button is pressed or the next 

morning’s wakeup.  The FLEXmax will transition to Float stage at the end of the completed 

equalization cycle.  

EX-Absorb   

There is an external DC source other than PV keeping the battery above the Absorbing voltage

set point.  The FLEXmax will stop charging because it is not needed. 

Floating  

The FLEXmax is in the Float stage of a three-stage cycle, regulating the battery voltage at the

Float voltage set point.  This stage is temperature compensated.  (See page 99.)  If the battery

voltage drops below the Float voltage, the FLEXmax will employ the MPPT function to draw

more power from the PV array.  (This may occur if the batteries are powering loads.)  If this

happens, the operating mode will change to MPPT Float.  (See below.) 

GT Mode  

The FLEXmax is in Grid-Tie mode.  In a system with an OutBack grid-interactive inverter, a

HUB, and a system display, the FLEXmax will display GT Mode, if and only if, the inverter is in

Sell mode and the FLEXmax is in the MPPT BULK or MPPT FLOAT modes.  This message

also indicates that Grid-Tie mode communication has been established between the inverter

and charge controller.  GT must be selected in the MPPT Mode advanced menu in order to be

viewed.  (See page 50.) 

High V

This indicates the PV array’s open-circuit voltage is too high for the controller to safely operate 

(> 145 Vdc).  This should only occur with systems using 72 Vdc nominal PV arrays in very cold

temperatures (below –15°C / 5°F).  The FLEXmax will automatically restart operation once the

PV array’s open-circuit voltage falls to a safe level (145 Vdc or lower).   

 

CAUTION:  Equipment Damage 

Voltages in excess of 150 Vdc are likely to damage the FLEXmax controller.  The PV array

should be designed to avoid ever reaching these voltages. 

Low Light or Snoozing  

  

A Low Light or Snoozing mode indicates that the PV voltage is high enough to activate the 

FLEXmax, but there is not enough current available to charge.  During the initial tracking (see

Wakeup and Tracking), if it is determined to be too late (or too early) in the day, the FLEXmax

will display Low Light for a few seconds and then display Snoozing for five minutes (default). 

This reduces energy usage and unnecessary powering of the FLEXmax.  This message is also

displayed in extremely cloudy weather.  

MPPT Bulk  

This is a Maximum Power Point Tracking mode that harvests the maximum wattage available

from the PV array.  The controller is trying to regulate the battery voltage towards the

Absorbing voltage set point.  Normally the charge controller enters this mode at the beginning 

of the day or when a new charge cycle begins.  The controller may also enter this stage if there

is not enough PV energy to maintain a different stage, such as Absorbing.  See page 22 for

more information. 

MPPT Float 

This is a Maximum Power Point Tracking mode that harvests the maximum wattage available

from the PV array.  The controller is trying to regulate the battery voltage towards the Float

voltage set point.  Normally, the charge controller enters this mode if it was in the Floating

mode (see above) and there was not enough energy to maintain the battery voltage. 

MPPT EQ 

The equalization cycle has started and the charge controller is trying to regulate the batteries at

the BATTERY EQUALIZE VOLTS set point.  Once this voltage has been reached, the

displayed mode will change to EQ.  

Before equalizing, battery loads should be turned off and the battery should be charged so the

charge controller can quickly reach the EQ voltage set point.  Otherwise, the charge controller

may have difficulty reaching or maintaining the equalization process.  

Equalization is not battery temperature compensated.   This mode tells the user that external conditions have changed.  After displaying this message, the charge controller will

enter Tracking mode to perform power point tracking again.   

The FLEXmax is measuring a new open-circuit panel voltage (V)

OvrCurrent  

This condition occurs if more than 6 amps flow from the battery to the FLEXmax, or if more

than 100 amps is drawn from the FLEXmax by the battery.  To reinitiate power production,

press <RSTRT> in the Misc menu (see page 48).  If this continues to occur, the unit may 

be malfunctioning.     

Over Temp    

The FLEXmax is too hot.  If this message appears, carefully check to see if the heat sink

is extremely hot.  To help control its operating temperature, avoid installing the FLEXmax in

direct sunlight. 

Re-Cal   

There are certain conditions that can confuse the current measuring method in the FLEXmax. 

If this happens, the FLEXmax will temporarily stop and re-calibrate.  This may happen because

of high temperatures or current flowing from the battery.  After displaying this message, the

charge controller will enter Tracking mode to perform power point tracking again.   

Sleeping   

The PV voltage is two volts less than the battery voltage.  This normally appears at night, when

no PV energy is available.  This may also appear during the day when the FLEXmax is 

transitioning between certain states, or due to other conditions.  After three hours of Sleeping,

the FLEXmax will transition to Zzzzz... mode. 


Sys Error   

This indicates an internal non-volatile memory error.  The unit will stop operating when this

message is displayed.  Support may be required. 

Tracking   

In Tracking mode, the FLEXmax is doing an initial tracking of the panel voltage from (V)


towards battery voltage after wakeup.  This is also displayed when the controller transitions from

a target setpoint (Absorbing,  Floating, or EQ) to the MPPT state (MPPT Bulk, MPPT Float,

or MPPT EQ). 

Unloaded   

The battery terminals have  become disconnected.  This may mean that the battery circuit

breaker breaker has tripped.  It can also appear if the nominal battery voltage is set too low.  

Wakeup   

As the PV open circuit voltage (V) rises above the battery system voltage by two volts, 

the FLEXmax prepares to deliver power to the batteries, although it does not perform MPPT 

in this mode.  During this period (initial tracking), the FLEXmax is calculating the PWM duty

cycles, turning on power supply voltages in the proper sequences, and making internal

calibrations.  It also measures a new V at this time.  In Wakeup, the daily statistics of a 

single FLEXmax (amp-hours, kilowatt-hours, etc.), will accumulate into the total statistics.  

The daily statistics and the end-of-day summary will clear, and the controller will begin logging 

a new “day”.  A FLEXmax combined with a HUB and a MATE-class system display will log this

information at midnight.  In a MATE3-class system display, the data logging will occur at the

interval scheduled in the data logging parameters. 

Zzzzz...    

The FLEXmax will display Zzzzz... after 3 hours of continuous Sleeping.  This transition

indicates that the controller recognizes it is night.  It will perform Wakeup when voltage is

available (see above).    

Initial Operation 

Figure 15 Initial Operation 

Changing the Settings on the FLEXmax 

Accessing the Main Menu    

The main menu allows the user to adjust and calibrate the FLEXmax for maximum performance.  

 

Status Screen

Turn the PV input circuit breaker ON.  The FLEXmax automatically detects 

In   113.6V   0.0 A

Out   12.5V   0.0 A

    0.000 kW  0.0 kWH

AUX: OFF      Sleeping 

Status Screen 

In   000.0V   0.0 A

Out   12.5V   0.0 A

    0.000 kW  0.0 kWH

AUX: OFF      Sleeping 

Status Screen

From the status screen, press SK1 

to open the main menu screen.

To return to the status screen from 

the main menu, press <EXIT> 

(also SK1). 

the PV input voltage.

The FLEXmax enters Wakeup, transitions to Tracking, and prepares to 

In   113.6V   0.0 A

Out   12.5V   0.0 A

    0.000 kW  0.0 kWH

AUX: OFF      Sleeping 

  

Figure 16 Accessing the Main Menu 

900-0009-01-00 Rev D 27 

Operation

 

charge the batteries by tracking the maximum power point of the PV array.

During the initial tracking, the input PV source is gradually loaded from the 

open-circuit voltage (V) to ½ of the V.

  Within this range, the FLEXmax seeks the maximum power point.   

When the FLEXmax goes into Re-Cal, Auto Restart, or Wakeup, modes,

among other conditions, it performs an initial tracking. 

If PV voltage registers 000V when the PV circuit breaker

is ON, check the polarity of the PV connections. 

Main Menu 

Charger  Aux   Light

  EQ    Misc  Advanced

  Logging    Stats 

EXIT          GO 

 

Operation

 

Main Menu Map 

Main Menu 

Charger  Aux   Light

  EQ    Misc  Advanced

  Logging    Stats 

EXIT          GO 

<EXIT> returns to the Status screen.

<> moves the cursor to the left. 

<> moves the cursor to the right.

<GO> goes to the setup screen for the 

chosen option. 

Charger  Aux   Light

  EQ    Misc  Advanced

  Logging    Stats 

EXIT          GO 

 Charger Aux   Light

  EQ    Misc  Advanced

  Logging    Stats 

EXIT          GO 

Charger  Aux   Light

  EQ    Misc  Advanced

  Logging    Stats 

EXIT          GO 

Charger  Aux   Light

 EQ   Misc  Advanced 

  Logging    Stats

EXIT          GO 

 Charger  Aux   Light

  EQ   Misc Advanced 

  Logging    Stats

EXIT          GO 

 Charger  Aux   Light

  EQ   Misc Advanced 

  Logging    Stats

EXIT          GO 

 Charger  Aux   Light

  EQ    Misc  Advanced 

 Logging    Stats

EXIT          GO 

 Charger  Aux   Light

  EQ    Misc  Advanced 

 Logging   Stats

EXIT          GO 

From the main menu, a user can choose among the

following FLEXmax functions by aligning the arrow

next to the desired selection. 




 

o Charger—CHARGER SETUP

Adjusts the Current Limit, Absorbing,  

 

and Float recharging voltage set points.

See page 29 for details. 

o Aux—AUX OUTPUT CONTROL

Provides a secondary control circuit for a vent 

 

fan, error alarm, and other system-related

additions. 

See page 30 for details. 

o Light—BACKLIGHT CONTROL

Adjusts the backlighting of LCD screen and soft 

 

key buttons.

See page 44 for details. 

o EQ—BATTERY EQUALIZE

Activates battery equalization recharging 

 

(manually or automatically).

See page 45 for details. 

o Misc—MISCELLANEOUS

Additional settings and service information.

See page 47 for details. 


 

o Advanced —ADVANCED MENU

Optimizes/fine-tunes the charge controller. 

See page 49 for details. 



 

o Logging—DATA LOGGING

Displays recorded power production information.

See page 57 for details. 


 

o STATS—STATISTICS

Displays recorded peak system information and 

cumulative kilowatt-hours and amp-hours.

See page 58 for details. 

Figure 17 Main Menu  

 

Charger Screen 

Charging settings should follow the battery manufacturer's recommendations.  This screen

allows changes to the recharging voltage set points if the default settings do not match the

battery manufacturer's recommendations.  (For an explanation of battery charging, see pages

98 and 99). 

o Current Limit 

o Absorbing 

o Float   

The default charger output current limit setting is: 

o 80 amps for the FM80, and 

o 60 amps for the FM60.   

This setting is adjustable from 5 to 80 amps.   

 

IMPORTANT:   

 Check the battery manufacturer’s recommendations for the optimal charging settings for

the type of batteries being used. 

 An appropriate circuit breaker, or overcurrent device, must be used between the battery

and the FLEXmax.   

 If a battery remote temperature sensor (RTS) is used, set the Absorbing and Float

setting voltage based on a 25°C/77°F setting.  RTS compensated voltage values can be 

Main Menu 

viewed in the Advanced menu screen under the RTS Compensation heading.  

Charger  Aux   Light

  EQ    Misc  Advanced

  Logging    Stats 

EXIT          GO 

Charger  Aux   Light

  EQ    Misc  Advanced

  Logging    Stats 

EXIT          GO 

Charger Screen 

Current Limit    80A

Absorbing        14.4V

Float            13.8V 

EXIT        -    + 

To access the Charger screen and adjust

the settings: 

1. From the main menu, press the <> or <> soft key

to move the  to the left of the Charger function. 

2. Press <GO> to open the Charger screen.  

The  indicates which set point is selected. 

3. Press <> to move the  to the set point that needs

to be changed. 

4. Press <+> to increase the value or (–) to decrease

the value. 

 

To Exit:

o Press <EXIT> once to return to the main menu. 

o Press <EXIT> twice to return to the status screen. 

Figure 18 Charger Setup Menu 

 

Operation

 

Aux Screens   

The AUX (Auxiliary) is a secondary control circuit — essentially, a small power supply that

provides a 12 Vdc output current (up to 200 milliamps / 2.4 watts) to an isolated load.  It is either

ON (Active High) with 12 Vdc available at the output or OFF (Active Low) with 0 Vdc at the

output.  It can also be set to AUTO, so that it activates when certain criteria are met. 

The AUX output can respond to specific criteria and control cooling fans, vent fans, load

diversion, fault alarms, and automatic generator control.  In some cases, such as the PV

Trigger, Night Light, or Diversion:Relay applications, the polarity of the output can be

reversed so that a lack of power activates the output.  This function is controlled through the

Aux Polarity screen in the ADVANCED MENU.  (See page 56.) 

NOTE:  Diversion:Relay and Diversion:Solid St can be used for AC coupling applications.

The AUX output can also be controlled externally through the system display.  See the literature 

for the system display (if used) for details. 

o Only one AUX MODE can operate at a time (even if other modes have been preset). 

Table 2 Aux Mode Functions 

Mode Name Function/Purpose Set Points Aux Polarity 

Vent Fan

Function: 

When the threshold voltage set point is exceeded,

the AUX output will change state for at least 15

seconds.  If the set point continues to be

exceeded, the output will remain in that state until

the voltage falls below the set point.   

Once the voltage decreases below the threshold

voltage, the AUX output will remain in that state for

another 15 seconds.  It will then deactivate.  

Purpose:

This mode is intended to operate a vent fan for a 

battery enclosure to ventilate hydrogen gas from

the enclosure.  

PV Trigger

Function: 

When the threshold voltage set point is exceeded, 

the AUX output will activate.  

When the threshold voltage decreases below the 

voltage set point, the output will remain active for

the duration of the hold time set by the user. 

Purpose:

This mode is intended to operate an alarm, or 

relay that disconnects the PV array, when

PV input exceeds the threshold voltage set by the

user.  The mode deactivates the alarm or

PV disconnect after the time set point has

been reached. 

NOTE:  Do not exceed 150 Vdc or the FLEXmax

could be damaged. 

 Threshold

Voltage 

 Threshold

Voltage 

 Hold

Time 

Not Available  

Active High:  Activates

the AUX output when 

the voltage exceeds the

set point. 

Active Low:  Deactivates

the AUX output when 

the voltage exceeds the

set point. 

Table 2 Aux Mode Functions 

Mode Name Function/Purpose Set Points Aux Polarity 

Error Output

Function: 

When the voltage decreases below the threshold

voltage for 10 minutes or more, the AUX output will

change state. 

Purpose:

This mode is useful for monitoring remote sites.   

It is intended to signal when the charge controller has not charged the batteries for 26 hours or more or if the battery voltage has fallen below the threshold voltage for more than 10 minutes. 

When set as Active Low, it can activate an alarm by sending a signal through a modem to a computer to alert the operator of the problem. 

Night Light Function: 

When the voltage drops below the threshold

voltage set point for the amount of time set in the

Hysteresis time, the AUX output changes states

and remains in that state for the amount of time

set for the ON time. 

Purpose:

This mode is intended to illuminate a 

user-provided, low wattage light for as long as 

the charge controller remains in Sleep mode or 

for the ON time set by the user. 

Float

Function: 

Diversion:

Relay 

Diversion:

Solid St 

 

When the FLEXmax is in the Float stage, the

output activates to power a load. 

Purpose:

This mode is intended to power a load when the 

FLEXmax is in the Float stage of charging the

batteries. 

Function:

When the battery voltage exceeds the threshold 

voltage, the AUX output changes state.  Often

used with wind or hydroelectric sources. 

Purpose:

This mode is intended to divert power from the 

batteries to prevent overcharging by activating  

a diversion load at the appropriate time. 

Function:

When the battery voltage exceeds the threshold 

voltage, the AUX output goes into pulse-width

modulation at a rate of 200 Hz.  Often used with

wind or hydroelectric sources. 

Purpose:

This mode is intended to divert power from the 

batteries to prevent overcharging by operating  

a diversion load at the appropriate PWM level. 

Recommended for use with a solid-state relay 

for fast and precise load control. 

 Threshold

Voltage 

 Threshold 

voltage 

 ON Time

 Hysteresis 

Time Operation Not Available 

Active High:  Activates 

for a set amount of time 

when the voltage drops

below the threshold for a

set amount of time. 

Active Low:  Deactivates 

for a set amount of time

when the voltage drops

below the threshold for a

set amount of time. 

None Not Available 

 Threshold

Voltage 

 Time 

 Threshold

Voltage 

 Time 

Active High:  Controls an

auxiliary load to divert

power away from the

batteries when a wind or

hydroelectric turbine is

connected directly to the

batteries. 

Active Low:  Deactivates

an auxiliary load to stop

diverting from batteries. 

Not Available 

Operation

 

Table 2 Aux Mode Functions 

Mode Name Function/Purpose Set Points Aux Polarity 

Low Battery

Disconnect 

Function:

When the battery voltage falls below the threshold 

disconnect voltage, the AUX output activates. 

When the battery voltage rises above the

threshold reconnect voltage, the AUX deactivates. 

Purpose:

This mode is intended to operate a relay to turn off 

loads and save battery capacity.   

Remote Allows an OutBack system display to control the

AUX output (see the system display manual

for details). 

 

AUX MODE Screen Navigation 

 

 

Main Menu 

Charger  Aux   Light

  EQ    Misc  Advanced

  Logging    Stats 

 EXIT          GO 

 Charger Aux   Light

  EQ    Misc  Advanced

  Logging    Stats 

 EXIT          GO 

AUX MODE Screen 

       AUX MODE     

     Night Light

Output: Off        Off

 EXIT  NEXT  SET  MODE 

NOTE:  If more than 10 minutes have passed

since any activity, the PASSWORD screen 

becomes active, requiring the user to reenter the

password (141).  

 Threshold

Voltage for

disconnect 

 Threshold

voltage for

reconnect 

 Time

delay 

Not Available 

None Not Available 

To access the AUX MODE screen and adjust the settings:

1. From the Main Menu, press <> or <> to move the  to the left 

of Aux.

 2. Press <GO> to open the Aux screen.  

3. Press <NEXT> to cycle through the available auxiliary modes.

4. Press <MODE> to cycle through the mode setpoints ON, OFF, or 

AUTO.   In AUTO mode, the function will automatically activate

when a user-determined value is met and deactivated (or shut down)

when other conditions are met, such as a certain amount of time

passing. 

5. Press <SET> to select the set point(s) (if available).

6. Press <EXIT> once to return to the main menu.

7. Press <EXIT> twice to return to the status screen. 

AUX MODE

Name

       AUX MODE     

      Night Light 

Output: Off        Off

 EXIT  NEXT  SET  MODE 

Figure 19 Aux Screen Navigation 

Aux Polarity

See page 56. 

AUX MODE

Set Point 

 

Vent Fan (AUX Mode)  

This mode is intended to operate a vent fan for a battery enclosure which helps ventilate

hydrogen gas from the enclosure.  If the voltage remains above the threshold voltage set point,

the vent fan will remain active.   

When the voltage falls back below the set point, the vent fan will continue running for another 

15 seconds, then turn off. 

Main Menu 

Charger  Aux   Light

  EQ    Misc  Advanced

  Logging    Stats 

 EXIT          GO 

 Charger Aux   Light

  EQ    Misc  Advanced

  Logging    Stats 

 EXIT          GO 

       AUX MODE     

       Vent Fan

Output: Off        Off

EXIT  NEXT  SET   MODE 

<NEXT> advances to the

next AUX MODE screen. 

       AUX MODE     

       Vent Fan

Output: Off        Off

EXIT  NEXT   SET  MODE 

       AUX MODE     

       Vent Fan


EXIT              VOLT 

     VENT FAN VOLTS     

       > 14.4 


 BACK   -     + 

To set the mode for Vent Fan:

1. From the Main Menu, press <> or <> to move the 

 to the left of Aux.

2. Press <GO> to open the AUX MODE screen.   

3. The Vent Fan screen should be the first default screen

to display.  If any other mode screen is displayed, press  <NEXT> to cycle through the available modes until Vent Fan is displayed again.  

Operation

 

4. Press <MODE> to switch between ON, OFF, or AUTO. 

o ON activates the AUX output. 

o OFF deactivates the AUX output.

o AUTO controls the output according to the criteria 

of the selected AUX mode. 

To change the set points for Vent Fan:

1. Press <SET> to advance to the setpoint screen.

2. Press <VOLT> to advance to the VENT FAN VOLTS screen.

3. Press <–> or <+> to increase or decrease the value.

4. Press <BACK> to return to the Vent Fan setpoint screen.

5. Press <EXIT> to return to the AUX Mode screen. 

To Exit:

o Press <EXIT> once to return to the main menu. 

o Press <EXIT> twice to return to the status screen. 

 

Operation

 

PV Trigger (AUX Mode)  

This mode is intended to operate an alarm or relay that disconnects the PV array when PV

input exceeds the threshold voltage set by the user.  The mode turns off the alarm or PV

disconnect after the PV voltage decreases below the threshold for a time period set by the user. 

 

 

CAUTION:  Hazard to Equipment 

Do not exceed 150 Vdc or the FLEXmax could be damaged. 

Main Menu 

Charger  Aux   Light

  EQ    Misc  Advanced

  Logging    Stats 

EXIT          GO 

 Charger Aux   Light

  EQ    Misc  Advanced

  Logging    Stats 

EXIT          GO 

       AUX MODE     

      PV Trigger

Output: Off        Off

EXIT  NEXT  SET   MODE 

<NEXT> proceeds to the

next AUX MODE screen. 

      AUX MODE     

      PV Trigger

Output: Off        Off

EXIT  NEXT   SET  MODE 

       AUX MODE     

      PV Trigger


EXIT        TIME  VOLT 

     Hold Time Sec      

         01.1


 BACK   -     + 

To set the mode for PV Trigger:

1. From the Main Menu, press <> or <> to move the  to the 

left of Aux.

2. Press <GO> to open the AUX MODE screen.   

3. Press <NEXT> until PV Trigger is displayed in the AUX

MODE screen. 

4. Press <MODE> to cycle through ON, OFF, or AUTO.   

o ON activates the AUX output. 

o OFF deactivates the AUX output.

o AUTO controls the output according to the criteria of the 

selected AUX mode. 

Indicates Aux Polarity is

Active High 

To change the set points for PV Trigger:

1. Press <SET> to advance to the setpoints screens; 

<VOLT> and <TIME>.

2. Press <–> or <+> to increase or decrease the 

values.

3. Press <BACK> to return to the setpoint screen. 

4. Press <EXIT> to return to the AUX Mode screen.

 

       PV VOLTS      

        > 140


 BACK   -     + 

To Exit:

o Press <EXIT> once to return 

to the main menu.

o Press <EXIT> twice to return 

to the status screen. 

Figure 21 Setting the PV Trigger Aux Mode 

 

Error Output (AUX Mode)  

This mode is useful for monitoring remote sites.  It is intended to signal when the charge

controller has not charged the batteries for 26 hours or more or if the battery voltage has fallen

below the threshold voltage for more than 10 minutes.  The 26-hour timer can be viewed. 

When set as Active Low, it can operate an alarm by sending a signal through a modem to a

computer to alert the operator of the condition. 

Main Menu 

Charger  Aux   Light

  EQ    Misc  Advanced

  Logging    Stats 

EXIT          GO 

 Charger Aux   Light

  EQ    Misc  Advanced

  Logging    Stats 

EXIT          GO 

       AUX MODE     

     ERROR OUTPUT

Output: On          On

EXIT  NEXT  SET   MODE 

<NEXT> proceeds to

the next AUX MODE 

       AUX MODE     

     ERROR OUTPUT

Output: Off        On

EXIT  NEXT   SET  MODE 

       AUX MODE     

     ERROR OUTPUT 

01 hrs

EXIT              VOLT 

ERROR LOW BATT VOLTS

        < 11.5 


 BACK   -     + 

To set the mode for Error Output:

1. From the Main Menu, press <> or <> to move the  to 

Figure 22 Setting the Error Output Aux Mode  

Operation

 

the left of the Aux function.

2. Press <GO> to open the AUX MODE screen.  

3. Press <NEXT> until ERROR OUTPUT is displayed in the AUX 

MODE screen.

4. Press <MODE> to cycle through ON, OFF, or AUTO.    

o ON activates the AUX output.

o OFF deactivates the AUX output.

o AUTO controls the output according to the criteria of the 

selected AUX mode.

 

NOTE:  To advance to the timer screen, press <SET>.  This timer counts up to

the 26-hour limit before the AUX output is activated. 

The voltage set point for this mode can also be changed.

To change the setpoint for ERROR OUTPUT: 

1. Advance to the timer screen as noted above.

2. Press <VOLT> to advance to the ERROR LOW BATT  

VOLTS screen.

3. Press <–> or <+> to increase or decrease the value. 

4. Press <BACK> to return to the ERROR OUTPUT setpoint screen.

5. Press <EXIT> to return to the AUX Mode screen. 

To Exit:

o Press <EXIT> once to return to the main menu.

o Press <EXIT> twice to return to the status screen. 

 

Operation

 

Night Light (AUX Mode)  

This mode is intended to operate a user-provided, low wattage light for as long as the charge

controller remains in Sleep mode or for the ON time set by the user.  OFF is the default value.  

Main Menu 

Charger  Aux   Light

  EQ    Misc  Advanced

  Logging    Stats 

EXIT          GO 

 Charger Aux   Light

  EQ    Misc  Advanced

  Logging    Stats 

EXIT          GO 

       AUX MODE     

      Night Light

Output: Off        Off

EXIT  NEXT  SET   MODE 

<NEXT> proceeds to the

next AUX MODE screen. 

      AUX MODE     

     Night Light

Output: Off        Off

EXIT  NEXT   SET  MODE 

       AUX MODE     

     Night Light


EXIT  HYST TIME VOLT 

      Night Light     

   ON Hysteresis Time

      Minutes  000

 BACK   -     +   OFF 

      Night Light      

  OFF Hysteresis Time

      Minutes  000

 BACK   -     + 

To set the mode for Night Light:

1. From the Main Menu, press <> or <> to move the  to 

the left of the Aux function.

 2. Press <GO> to open the AUX  MODE screen.   

The  indicates that the mode supports polarity.  See page 56.

3. Press <NEXT> until Night Light is displayed in the AUX 

MODE screen.

4. Press <MODE> to cycle through ON, OFF, or AUTO.    

o ON activates the AUX output.

o OFF deactivates the AUX output.

o AUTO controls the output according to the criteria of the 

selected AUX mode. 

Indicates Aux Polarity

is Active High 

To change the set points for Night Light:

1. Press <SET> to advance to the set point screens <HYST>, 

<VOLT>, and <TIME>.

2. Press <–> or <+> to increase or decrease the values.

3. Press <BACK> to return to the ERROR OUTPUT set point screen. 

4. Press <EXIT> to return to the AUX Mode screen.

 

  Night Light On Time   

       Hours 23


 BACK   -     + 

Adjusts the amount of

time the night light

remains on. 

To Exit:

o Press <EXIT> once to return to the main menu.

o Press <EXIT> twice to return to the status screen. 

      Night Light 

   Threshold Voltage

          010

 BACK   -     + 

Adjusts the threshold of

the voltage that triggers

the function. 

Figure 23 Setting the Night Light Mode 

 

Float (AUX Mode)  

This mode is intended to operate a load when the FLEXmax is in the Float stage of charging 

the batteries. 

Main Menu 

Charger  Aux   Light

  EQ    Misc  Advanced

  Logging    Stats 

EXIT          GO 

 Charger Aux   Light

  EQ    Misc  Advanced

  Logging    Stats 

EXIT          GO 

       AUX MODE     

         Float

Output: Off        Off

EXIT  NEXT  SET   MODE 

<NEXT> proceeds to the

next AUX MODE screen. 

Figure 24 Setting the Float Mode  

Operation

 

To set the mode for Float:

1. From the Main Menu, press <> or <> to move the  to the 

left of Aux.

2. Press <GO> to open the AUX  MODE screen.  

3. Press <NEXT> until Float is displayed in the AUX MODE screen.

4. Press <MODE> to cycle through the mode set points ON, OFF,  

or AUTO.   

o ON activates the AUX output. 

o OFF deactivates the AUX output.

o AUTO controls the output according to the criteria of the 

selected AUX mode. 

To Exit:

o Press <EXIT> once to return to the main menu.

o Press <EXIT> twice to return to the status screen. 

 

Operation

 

Diversion (AUX Mode)  

When external DC sources (wind, hydroelectric) are directly connected to a battery bank, any

excess power should be sent to a diversion load, such as a heating element, using a

mechanical relay or solid-state relay.   

In Diversion mode, the user programs set points — from –5.0 volts to 5.0 volts relative to the

Absorbing, Float, and EQ voltages — to activate the AUX output.   The Diversion AUX mode can

be active (ON) when the battery voltage is raised above one of these set points for a certain

amount of time or inactive (OFF) when it falls below.  This application should not be used with a mechanical relay.  It requires

the use of a resistive load and should not be used with other sorts of loads. 

Diversion: Relay Mode   

Main Menu 

Charger  Aux   Light

  EQ    Misc  Advanced

  Logging    Stats 

EXIT          GO 

 Charger Aux   Light

  EQ    Misc  Advanced

  Logging    Stats 

EXIT          GO 

       AUX MODE     

Diversion: Relay

Output: Off        Off

EXIT  NEXT  SET   MODE 

<NEXT> proceeds to the

next AUX MODE screen. 


 


IMPORTANT:   

If using wind or hydroelectric turbines, keep the

charge controller’s diversion voltage slightly above

the Absorbing and Float voltage settings for

efficient functioning. 

To set the mode for Diversion:Relay:

1. From the main menu, press <> or <> to move the  to 

the left of Aux.

 2. Press <GO> to open the AUX MODE screen.   

3. Press <NEXT> until Diversion:Relay is displayed in the

AUX MODE screen. 

4. Press <MODE> to cycle through the mode set points ON,

OFF, or AUTO.    

o ON activates the AUX output.

o OFF deactivates the AUX output.

o AUTO controls the output according to the criteria of the 

selected AUX mode

To change the set points for Diversion:Relay:

1. Press <SET> to advance to the set point screens <VOLT>  Operation and <TIME>.

2. Press <TIME> to advance to the Time screen.  This allows the 

user to adjust the minimum time the AUX output is active after

the battery voltage falls below the hysteresis voltage. 

3. Press <-> or <+> to increase or decrease the Hold time values.

4. Press <DLY+> to increase the Delay Time. 

5. Press <BACK> to return to the Diversion:Relay TIME and

VOLT screen. 

6. Press <VOLT> to move into the Relative Volts screen.

7. Press <–> or <+> to increase or decrease the values.

8. Press <HYST> to select the hysteresis value.

9. Press <BACK> to return to the main Diversion:Relay TIME 

and VOLT screen.

10. From the Diversion:Relay screen, press <EXIT> to return to 

the AUX MODE screen. 

       AUX MODE     

Diversion:Relay


EXIT        TIME  VOLT 

Hold             Delay

01.0      Time      00

         Seconds

 BACK   -     +   DLY+ 

Hold time shows how long the AUX output

stays active after the battery voltage has

fallen below the HYST (hysteresis) set

point.  The user can adjust the Hold time

from 0.1 to 25 seconds.  

The Delay time shows how long the

battery voltage must be above the

Relative Volts before the AUX mode is

activated.  It can be adjusted from 0 to

24 seconds, but is rarely required.   

Pressing the <BACK> soft key returns to

the AUX MODE Diversion: Relay TIME 

and VOLT screen. 

 

      AUX MODE     

Diversion:Relay

Output: Off        Off

EXIT  NEXT   SET  MODE 

To Exit:

o Press <EXIT> once to 

return to the main menu.

o Press <EXIT> twice to 

  Absorb--Float--EQ

     Relative Volts

          0.0     00.2

 BACK   -     +   HYST 

return to the status screen. 

Use this screen to establish the set points for

starting and ending the AUX mode relative to the

Absorb, Float, and EQ voltages.  

The <HYST> (hysteresis) set point establishes

when the AUX mode becomes inactive after the 

battery voltage falls below the Relative Volts

voltage minus the hysteresis value.  

 

Operation

 

Diversion: Solid St (AUX Mode)   

 

 

Main Menu 

Charger  Aux   Light

  EQ    Misc  Advanced

  Logging    Stats 

EXIT          GO 

 Charger Aux   Light

  EQ    Misc  Advanced

  Logging    Stats 

EXIT          GO 

       AUX MODE     

Diversion:Solid St

Output: Off        Off

EXIT  NEXT  SET   MODE 

<NEXT> proceeds to the

next AUX MODE screen. 

 


IMPORTANT:   

 If using wind or hydroelectric turbines, keep

the charge controller’s diversion voltage

slightly above its Absorb and Float voltage

settings for efficient functioning. 

 Do not use Diversion:Solid St with a

mechanical relay.  The PWM action could

cause irregular relay activity.   

 Diversion:Solid St requires the use of a 

purely resistive load.  The PWM action may

work poorly with mechanical loads. 

To set the mode for Diversion:Solid St: 

1. From the main menu, press <> or <> to move the  to 

the left of Aux.

 2. Press <GO> to open the AUX MODE screen. 

3. Press <NEXT> until the Diversion:Solid St mode is

displayed in the AUX MODE screen. 

4. Press <MODE> to cycle through ON, OFF, or AUTO.   

o ON activates the AUX output. 

o OFF deactivates the AUX output.

o AUTO controls the  output according to the criteria of 

the selected AUX mode.

      AUX MODE     

Diversion:Solid St

Output: Off        Off

EXIT  NEXT   SET  MODE 

To change the set points for Diversion:Solid St:

1. Press <SET> to advance to the set point screens <VOLT>  Operation and <TIME>.

2. Press <TIME> to advance to the Time screen.  This allows the 

user to adjust the minimum time the AUX output is active after

the battery voltage falls below the hysteresis voltage. 

3. Press <-> or <+> to increase or decrease the Hold time values.

4. Press <DLY+> to increase the Delay time.

5. Press <BACK> to return to the Diversion:Solid St TIME and 

VOLT screen.

6. Press <VOLT> to move into the Relative Volts screen. 

7. Press <-> or <+> to increase or decrease the values.

8. Press <HYST> to select the hysteresis value.

9. Press <BACK> to return to the Diversion:Solid St Time and 

Volt screen.

10. From the Diversion:Solid St screen, press <EXIT> to return to 

 

the AUX MODE screen. 

       AUX MODE     

Diversion:Solid St


EXIT        TIME  VOLT 

Hold             Delay

01.0      Time      00

         Seconds 

 BACK   -     +   DLY+ 

Hold time shows how long the AUX mode

stays active after the battery voltage has

fallen below the HYST (Hysteresis) set

point. The user can adjust the Hold time

from 0.1 to 25 seconds.  

The Delay Time shows how long the 

battery voltage must be above the 

Relative Volts before the AUX mode is

activated.  It can be adjusted from 0 to

24 seconds, but is rarely required.  

  Absorb--Float--EQ

     Relative Volts

          0.0     00.2 

 BACK   -     +   HYST 

Use this screen to establish the set points for

starting and ending the AUX mode relative

to the Absorb, Float, and EQ voltages.  

The <HYST> (hysteresis) set point establishes

when the AUX mode becomes inactive after the

battery voltage falls below the Relative Volts 

voltage minus the HYST value.  

 

To Exit:

o Press <EXIT> once to return to the main menu.

o Press <EXIT> twice to return to the status screen. 

 

Operation

 

Low Battery Disconnect (AUX Mode)  

This mode disconnects “auxiliary” loads from the batteries in the event of low voltage.  These

are separate from the usual loads.  Auxiliary loads are controlled by the AUX output, usually by

a larger relay.  When the battery voltage falls below the DISCONNECT VOLTS setting, AUX loads

are disconnected.  When it rises above RE-CONNECT VOLTS, they will be reconnected. 

Any loads not controlled this way, such as an inverter, may continue discharging the battery. 

Main Menu 

Charger  Aux   Light

  EQ    Misc  Advanced

  Logging    Stats 

EXIT          GO 

 Charger Aux   Light 

  EQ    Misc  Advanced 

  Logging    Stats

EXIT          GO 

       AUX MODE     

  Low Batt Disconnect

Output: Off        Off

EXIT  NEXT  SET   MODE 

<NEXT> proceeds to the

next AUX MODE screen. 

      AUX MODE     

  Low Batt Disconnect

Output: Off        Off

EXIT  NEXT   SET  MODE 

       AUX MODE     

  Low Batt Disconnect

 

EXIT        TIME  VOLT 

Figure 28 Low Battery Disconnect Mode 

900-0009-01-00 Rev D 43 

Operation

 

To set the mode for Low Battery Disconnect in AUX mode:

1. From the main menu, press <> or <> to move the  to the left 

of the Aux.

2. Press <GO> to open the AUX MODE screen.   

3. Press <NEXT> until the Low Batt Disconnect Mode is displayed

in the AUX MODE screen. 

4. Press <MODE> to cycle through the mode set points;

 ON, OFF, or AUTO.    

o ON activates the AUX output.

o OFF deactivates the AUX output.

o AUTO controls the output according to the criteria of the 

selected AUX mode. 

To change the set points for Low Battery Disconnect:

1. Press <SET> to advance to the set point screens <VOLT> and <TIME>.

2. Press <TIME> to advance to the Delay Time Sec screen. 

3. Press <–> or <+> to increase or decrease the values.

4. Press <BACK> to return to the main Low Batt Disconnect screen.

5. Press <VOLT> to advance to the DISCONNECT VOLTS screen.

6. Press <–> or <+> to increase or decrease the values.

7. Press <RECON> to advance to the RE-CONNECT VOLTS screen.

8. Press <–> or <+> to increase or decrease the values.

9. Press <DisV> to return to the DISCONNECT VOLTS screen.

10. Press <BACK> to return to the Low Batt Disconnect screen.

 

    Delay Time Sec     

         01      Timer 

                   001 

This is the time the FLEXmax waits before either 

activating or deactivating the AUX mode when either

the disconnect or reconnect voltages are reached.   

When the low voltage occurs, the timer shows the

seconds remaining before disconnecting.   

    DISCONNECT VOLTS    

        < 13.6


 BACK   -    +   ReCon 

    RE-CONNECT VOLTS     

        > 14.4


 BACK   -    +    DisV 

To Exit:

o Press <EXIT> 

once to return to

the main menu. 

o Press <EXIT>

twice to return to 

the status screen. 

 

Operation

 

Remote (AUX Mode)   

Remote allows an OutBack system display to control the charge controller's AUX output.  Some 

displays may require a certain level of software in order to use this feature.  Consult the owner's

manual for the system display being used for details. 

Main Menu 

Charger  Aux   Light

  EQ    Misc  Advanced

  Logging    Stats 

EXIT          GO 

 Charger Aux   Light

  EQ    Misc  Advanced

  Logging    Stats 

EXIT          GO 

       AUX MODE     

        Remote

Output: Off        Off

EXIT  NEXT  SET   MODE 

Backlight  

Figure 29 Setting the Remote Mode 

The Backlight selection allows the LCD and soft keys to remain illuminated for up to nine

minutes whenever any soft key is pressed.  The default setting for this mode is AUTO.  Pressing

any soft key when the LCD is not illuminated does not change any settings. 

Main Menu 

Charger  Aux   Light

  EQ    Misc  Advanced 

  Logging    Stats

EXIT   GO

Charger  Aux   Light

  EQ    Misc  Advanced

  Logging    Stats 

EXIT   GO

   BACKLIGHT CONTROL 

 Auto Time 2 Minutes

                  AUTO

EXIT    -     +   MODE 

To set the mode for Remote:

1. From the main menu, press <> or <> to move the  to the left 

of the Aux.

 2. Press <GO> to open the AUX MODE screen.   

3. Press <NEXT> until the Remote mode is displayed in the AUX

MODE screen. 

4. Press <MODE> to cycle through ON, OFF, or AUTO.   

o ON activates the AUX output. 

o OFF deactivates the AUX output.

o AUTO controls the output according to the criteria of the 

To set the mode for Backlight:

1. From the main menu, press <> or <> to move the  

to the left of Light.

2. Press <GO> to open the Backlight Control screen.   

3. Press < MODE> to cycle through ON, OFF, or AUTO.   

o ON activates the backlight. 

o OFF deactivates the backlight.

o AUTO activates the backlight on a timer.   

4. Press <–> or <+> to increase or decrease the number of

minutes (up to 9) for the Auto Time mode. 

5. Press <EXIT> twice to return to the status screen. 

 

selected AUX mode.  This setting may be required depending on

the type of system display being used. 

To Exit:

o Press <EXIT> once to return to the main menu.

o Press <EXIT> twice to return to the status screen. 

The AUX output can be used for the AGS (Advanced Generator Start)

function of a system display.  Remote must be activated for this to work. 

The system display must be set to the HUB port used by the FLEXmax.  If

using a MATE-class system display, see page 83 of this book.  If using the

MATE3-class, see page 69.  See the product literature for more information. 

To Exit:

o Press <EXIT> once to return to the main menu.

o Press <EXIT> twice to return to the status screen. 

EQ – Battery Equalize   

Equalization is a controlled overcharge that is part of regular battery maintenance.  Equalization

brings the batteries to a much higher voltage than usual and “simmers” them for a period of

time.  This has the result of removing inert compounds from the battery plates and reducing

stratification in the electrolyte.  Equalization follows the same pattern as standard three-stage

charging.  However, instead of the Absorption voltage set points, it is controlled by the Battery

Equalize Volts settings.  The time is controlled by the Battery Equalize Time setting. 

Equalization is normally performed only on flooded lead-acid batteries.  The schedule for

equalization varies with battery use and type, but it is usually performed every few months.   

If performed correctly, this process can extend battery life by a considerable amount.   

CAUTION:  Battery Damage 

 Do not equalize any sealed battery types (VRLA, AGM, Gel, or other) unless approved

by the manufacturer.  Some batteries may suffer severe damage from equalization. 

 Contact the battery manufacturer for recommendations on equalization voltage, 

MAIN  Menu 

Charger  Aux   Light

  EQ    Misc  Advanced

  Logging    Stats 

EXIT          GO 

Charger  Aux   Light

 EQ    Misc Advanced 

  Logging    Stats

EXIT          GO 

   BATTERY EQUALIZE

         Volts

         15.0

EXIT  NEXT  -EQV  +EQV 

   BATTERY EQUALIZE

         Time

       01 Hours

EXIT  NEXT  -HRS  +HRS 

   BATTERY EQUALIZE

1 Hours     15.0 Volts 

   Check water level

BACK  AUTO  START STOP 

duration, schedule, and/or advisability.  Always follow manufacturer recommendations

for equalization.   

Figure 31 Using Equalization 

900-0009-01-00 Rev D 45 

Operation

 

To change the EQ mode settings:

1. From the main menu, press <> or <> to move the  to the 

left of EQ.

2. Press <GO> to open the BATTERY EQUALIZE Volts screen.   

3. Press <-EQV> to decrease the value.

4. Press <+EQV> to increase the value.

5. Press <NEXT> to advance to the Battery Equalize Time screen.

6. Press <-HRS> to decrease the value.

7. Press <+HRS> to increase the value.

8. Press <NEXT> to advance to the  

Battery Equalize Start screen.

9. Choose one of the following equalization modes: 

o Press <START> to start a manual equalization charge.  

o Press <STOP> to stop an equalization charge.

o Press <AUTO> to view the auto equalization screen.  

See Figure 32 for details. 

To Exit:

o Press <EXIT> once to return to the main menu.

o Press <EXIT> twice to return to the status screen. 

 

Operation

 

Automatic Equalization Mode

To enable an automatic equalization mode, an interval must be set for the number of days to pass between 

equalization cycles.  This interval can be between 1 to 250 days.  The default equalization interval setting is

000 which disables this feature. 

The Equalization Interval screen allows the user to set the interval between equalization cycles.  It also

displays how many days of the interval have passed.  The COUNT value will be cleared to 000 when an

equalization cycle is started, manually stopped, or if the charge controller has been powered off. 


Days of the interval

that has elapsed

BATTERY

EQUALIZE START 

   BATTERY EQUALIZE

1 Hours     15.0 Volts

    Check water level

BACK  AUTO  START STOP 

Equalization

Interval Screen 

COUNT      EQ INTERVAL

 000           000


EXIT        -DAY +DAY 

Status Screen 

In    11.6V   0.0 A

Out   13.8V   0.0 A

    0.000 kW  0.0 kWH

AUX: OFF      EQ-MPPT 

In    11.6V   0.0 A

Out   13.8V   0.0 A

    0.000 kW  0.0 kWH

AUX: OFF      EQ 0:00 

In    11.6V   0.0 A 

Out   13.8V   0.0 A

    0.000 kW  0.0 kWH

AUX: OFF      EQ DONE 

Equalization Interval Screen 

COUNT      EQ INTERVAL

 000           000


EXIT        -DAY +DAY 

To enable an automatic EQ cycle:

1. Press <AUTO> to display the equalization interval screen.

2. Use <-DAY> or <+DAY> to set the number of days between 

each equalization cycle. 

3. Press <BACK> to return to the status screen. 

 

EQ INTERVAL

(1 to 250) 

To Exit:

o Press <EXIT> once to return to the EQ screen. 

On the Status Screen:

o EQ-MPPT will display to indicate the FLEXmax is trying to reach the 

target equalize set point.

o EQ 0:00 in Hours:Minutes will display after the set point is reached.

o After recharging, an EQ DONE message displays and a Float cycle 

begins.  EQ DONE is displayed until (1) any soft key is pressed, or

(2) a new day occurs for systems using an OutBack system display. 

The incomplete equalization cycle continues into the next day unless the

FLEXmax is powered off or manually stopped.  The remaining EQ time

can be viewed in the End-of-day Summary screen (see page 20). 

EQ cycle terminates when the equalization time period is reached. 

Figure 32 Setting the EQ AUTO Interval 

46 900-0009-01-00 Rev D 

 

Misc Screen   

There are three Misc screens that provide technical information about the operating state of the

system.   These are read-only screens and allow for no changes to any of the settings.  They do

provide the means to wake up the charge controller if it is in Snooze mode.  They also provide a

means to force the charger into a Bulk or Float stage.  

Main Menu 

Charger  Aux   Light

  EQ    Misc  Advanced

  Logging    Stats 

EXIT          GO 

Charger  Aux   Light

  EQ  Misc  Advanced 

  Logging    Stats

EXIT          GO 

GT  STATE  PWM%   ChgT

255   07   50.0    005


EXIT  NEXT       RSTRT 

GT  STATE  PWM%   ChgT

255   07   50.0    005


EXIT  NEXT       RSTRT 

GT  STATE  PWM%   ChgT

255   07   50.0    005 


EXIT  NEXT       RSTRT 

GT  STATE  PWM%   ChgT

255   07   50.0    005


EXIT  NEXT       RSTRT 

Operation

 

 To access the Misc screens:

1. From the Main Menu, press <> or <> to move the  

to the left of the Misc function 

 2. Press <GO> to open the Misc screen.  

 

Misc Screen #1 

GT  STATE  PWM%   ChgT

255   07   50.0    005


EXIT  NEXT       RSTRT 

A number below GT means the FLEXmax is in grid-tie mode

and communicating with an OutBack grid-interactive inverter. 

These numbers are for engineering purposes and are not

significant in normal use.  If the inverter is not grid-interactive,

then this number will read 000.  (See pages 51 and 104.)    

Each MPPT operation has a state which is indicated by a

number.  These numbers are for engineering purposes and

are not significant in normal use.   

 

This indicates the percentage of "on" time for the FETs as

they are performing pulse width modulation. 

The charge timer (ChgT) counts up to the Absorb

time limit when the charger is in the Absorb stage. 

See pages 22 and 52.   

Misc Screen #1 

GT  STATE  PWM%   ChgT

255   07   50.0    005 


EXIT  NEXT       RSTRT 

Press <EXIT> to return to the

Main Menu. 

Press <NEXT> to continue to

the Force Bulk/Float screen. 

 

Operation

 

Misc Screen #1 

GT  STATE  PWM%   ChgT

255   07   50.0    005


EXIT  NEXT       RSTRT 

Misc Screen #1 

GT  STATE  PWM%   ChgT

255   07   50.0    005


EXIT  NEXT       RSTRT 

Force Bulk/Float 



              FORCE

EXIT  NEXT FLOAT  BULK 

PCB  Target  BTMP  CFB

512  14.4v   255  0712


EXIT  BACK 

PCB  Target  BTMP  CFB

512  14.4v   255  0712


EXIT  BACK 

PCB  Target  BTMP  CFB

512  14.4v   255  0712


EXIT  BACK 

PCB  Target  BTMP  CFB

512  14.4v   255  0712


EXIT  BACK 

To bring the charge controller out of Snoozing mode:

1. Press <RSTRT>.

2. Press <EXIT> to return to the main menu. 

To force the charger into a Bulk or Float charge cycle:

1. Press <NEXT>. 








 

2. Select either a Float or Bulk charge cycle.  Forcing a Float or 

Misc Screen #2 

PCB  Target  BTMP  CFB

512  14.4v   255  0712


EXIT  BACK 

o Press <BACK> to return to the

Force Bulk/Float screen. 

o Press <EXIT> twice to return to

the main menu. 

PCB represents the temperature of the internal components. 

It is used to control the cooling fan.  These values are in

digital counts, not degrees.  The lower the number, the higher

the temperature.  (25°C is approximately a value of 525.) 

The target voltage the controller is trying to reach.  This will

depend on the active stage of the charger and the set target

value for that stage.   

BTMP is a battery temperature sensor reference value, used to

compensate the charging voltage.  The range is 0 to 255. 

These values are in digital counts, not degrees.   

An X next to this value indicates an external RTS is being used

in a system with a HUB and system display. 

 

Bulk recharge will end an EQ cycle.  See page 22 for details on

these modes. 

o Press <FLOAT> to force a Float charge.

o Press <BULK> to force a Bulk charge. 

3. Press <EXIT> to return to the main menu, or  

press <NEXT> to view the next miscellaneous screen. 

CFB represents Current FeedBack.  This is the output value of

the internal current sensor and is used to calculate output

amps and watts to track the maximum power point of the array. 

Figure 34 Miscellaneous Screen #2 

 

Advanced Menu   

The Advanced menu allows fine-tuning of the FLEXmax operations including Snooze periods

and Maximum Power Point limits (see page 97).  The following modes are available in

the Advanced menu.  They will appear in the following order. 

o Snooze Mode  

o Wakeup 

o MPPT Mode 

o Park Mpp 

o Mpp Range Limit % Voc

o Absorb Time  

o Rebulk Voltage 

o Vbatt Calibration 

o RTS Compensation 

o Auto Restart

o Aux Polarity   

o Reset to Defaults? 

 

Main Menu 

Charger  Aux   Light

  EQ    Misc  Advanced

  Logging    Stats 

EXIT          GO 

 Charger Aux   Light

  EQ   Misc Advanced 

  Logging    Stats

EXIT          GO 

Figure 35 Accessing the Advanced Menu 

Snooze Mode (Advanced Menu)    

Snoozing occurs if the charging current does not reach the user-selected cutoff current set point

as shown in this screen.  

Snooze Mode 

     ADVANCED MENU

      Snooze Mode

       < 0.6 amp

EXIT  NEXT        AMP  

Operation

 

To Access the Advanced Menus:

1. From the main menu, press <> or <> to move the  

to the left of Advanced.



 

2. Press <GO> to open the first Advanced menu screen.  

3. Press <NEXT> to cycle through the available modes.  The 

Snooze Mode screen should be the first screen to display.

4. Press <EXIT> to return to the status screen. 

To adjust the set point in the Snooze Mode screen:

1. Navigate to the Snooze Mode screen through the  

ADVANCED MENU as instructed in Figure 35.

2. Press <AMP> to adjust the amp setting.   

Amp values increments include:  0.2, 0.4, 0.6, 0.8 and 1.0.

3. Press <NEXT> to advance to the Wakeup Mode screen. 

To Exit:

o Press <EXIT> once to return to the main menu.

o Press <EXIT> twice to return to the status screen. 

 

 

Operation

 

Wakeup Mode  (Advanced Menu)      

Wakeup Mode sets the open-circuit voltage (V) conditions that cause the charge controller to

wake up during Sleep and Snooze modes.   Since environmental conditions impact the

open-circuit voltage of an array, the V can be based on the last measured V value.  

Before changing these values, monitor the system for a week or so using the factory defaults 

and then gradually adjust the set points.  If the set points are set too high, the charge controller

might not wake up soon enough or often enough, which means a loss of power production.  

     ADVANCED MENU

      Wakeup Mode

       < 0.6 amp

EXIT  NEXT        AMP 


MPPT Mode (Advanced Menu)    

This screen allows the user to choose from the following modes: 

o Auto Track MPPT mode (default) automatically tracks the PV upon wakeup and then tracks the MPP

of the array.  If Auto Restart is set to 1 or 2, the charge controller awakes every 1.5 hours and does

an initial tracking.  (See page 55.) 

o U-Pick % (V) MPPT mode allows the user to manually adjust the MPP tracking limit as a

percentage of the array's open-circuit voltage (V)

Wakeup Mode

Amp Settings  

Wakeup Mode

Voltage Settings  

     ADVANCED MENU

      Wakeup Mode

             1.5V  05m

EXIT  NEXT   +VOC -Min 

 This percentage is displayed in the Park Mpp %  screen along with the current output wattage.  (See page 51.)  The wattage value changes as the user adjusts the V percentage, letting the user lock in the most advantageous percentage value. 

U-Pick % acquires a new V

MPPT Mode 

     ADVANCED MENU

       MPPT Mode

      Auto Track

EXIT  NEXT  nonGT MODE 

To adjust the set points in Wakeup Mode:

1. Navigate to the Wakeup Mode screen through the  

ADVANCED MENU as instructed in Figure 35.

2. Press <AMP> to adjust the amp setting.  Amp values 

increment include:  0.2, 0.4, 0.6, 0.8 and 1.0.

3. Press <NEXT> for the voltage settings screen. 

4. Press <+VOC> or <-Min> to adjust the voltage and

delay settings.  

o <+VOC> ranges from 1.5 V up to 9.5 V  

o <+MIN> ranges from 5 up to 15 minutes  

5. Press <NEXT> for the MPPT Mode screen.

To Exit: 

o Press <EXIT> once to return to the main menu.

o Press <EXIT> twice to return to the status screen. 

 value every 1.5 hours if Auto Restart is set to 1 or 2. 

To select the MPPT Mode:

1. Navigate to the MPPT Mode screen through the 

ADVANCED MENU as instructed in Figure 35.

2. Press <MODE> to choose an MPPT mode.  If the system has an 

OutBack grid-interactive inverter with a HUB and system display,

press <nonGT> to change it to <GT>.   This will place the 

controllers in GT mode to allow the inverter to sell excess power. 

3. Press <NEXT> to view the Park Mpp screen. 

To Exit:

o Press <EXIT> once to return to the main menu.

o Press <EXIT> twice to return to the status screen. 

o MPPT Mode – Auto Track 

 GT allows the FLEXmax to work more effectively with a grid-interactive OutBack inverter.  This setting

automatically raises the charge controller’s Float voltage to equal its Absorption voltage.  Since the

inverter sells power to maintain its own Float, Absorption, or Sell settings (all of which should be lower

than those of the controller), this mode makes it easier for the inverter to sell power.  (See pages 47

and 104 for more information on this mode.)

   

 

NOTE

:  The charge controller’s Float voltage returns to normal any time the inverter enters

PassThru or Silent modes.  (See the inverter Operator's Manual for inverter modes.)  

 The Park Mpp screen will be slightly different between Auto Track mode and U-pick mode.  In the

U-pick mode, the Watts will appear in addition to the %Voc value. 

 

MPPT Mode

Auto Track 

     ADVANCED MENU

       MPPT Mode

      Auto Track

EXIT  NEXT  nonGT MODE 

Auto Track Park Mpp 

     ADVANCED MENU

       Park Mpp

              77 % Voc

EXIT  NEXT   -%    +% 

Mpp Range Limit % Voc 

     ADVANCED MENU

Mpp Range Limit %VOC

             Min   Max

EXIT  NEXT   1/2   90% 

MPPT Mode

U-pick% 

     ADVANCED MENU

       MPPT Mode

        U-pick%

EXIT  NEXT  nonGT MODE 

U-pick% Park Mpp 

     ADVANCED MENU

       Park Mpp

Watts 0251    77 % Voc

EXIT  NEXT   -%    +% 

Mpp Range Limit % Voc 

     ADVANCED MENU

Mpp Range Limit %VOC

             Min   Max

EXIT  NEXT   1/2   90% 

The Mpp Range Limit % Voc adjusts the upper range limit 

of the  FLEXmax charge controller’s maximum power point

(MPP) tracking.   

The default Max MPP voltage limit is set at 90% of the V


and is normally not adjusted for a PV array.  If necessary, the

adjustable limits are 80%, 85%, 90%, and 99% of the V

Min optimizes the tracking window for MPPT.  The default

Min setting of 1/2 establishes the lower limit of this window as

one-half the V

The Min range limit setting may be set to FULL if something

other than a PV array is connected to the input of the

FLEXmax, such as a hydroelectric turbine (see page 102). 

However, the input voltage must never exceed 150 Vdc at

any time.  

Operation

 

To adjust the Park Mpp voltage 

percentage settings: 

1. Press <NEXT> to view the Mpp Range

Limit % VOC screen. 

2. Choose one of the following options:

o Press <-%> to decrease the value. 

o Press <+%> to increase the value.

3. Press <NEXT> to advance to the 


Mpp Range Limit %Voc screen. 

4. Press <Min> or <Max> to adjust the

MPP range limit.  


 

To Exit:

o Press <EXIT> once to return to the main 

menu. 

o Press <EXIT> twice to return to the

status screen. 

o Press <NEXT> to advance to the

Absorb Time Limits screen. 

 

Operation

 

Absorb Time Limits (Advanced Menu)         

The amount of time the charge controller stays in the Absorbing stage of charging can be

adjusted in the Absorb Time Limits screen.  An Absorbing charge stage normally ends when

the battery voltage is maintained at the Absorbing set point for the time period set in the Absorb

Time Limits screen.   

o

 Absorb Time is adjustable from 0 to 24 hours (consult the battery manufacturer’s recommendations).

o

 When the Absorb Time Limit is reached, the charge controller goes into Float stage and may briefly 

 

display Charged, then Float.  When the battery voltage drops below the Float voltage set point, the

charge controller recharges to maintain this set point, employing the MPPT function in MPPT

Float mode. 

Figure 40 Absorb Time Limits Screen  

Absorb End Amps (Advanced Menu)    

While the battery voltage is at or above the Absorbing voltage target (see page 22) and the

Absorb End Amps value is reached for a time delay of 15 seconds, the charge controller will

switch to the Float stage.  This happens regardless of the charger time minutes as shown in the

Misc menu under ChgT (see page 47).  The charger timer will be reset to zero.  

 

Absorb Time Limits

To adjust the set points in the Absorb Time Limits screen: 

     ADVANCED MENU

  Absorb Time Limits

            01.0 hours

EXIT  NEXT    -    + 

Absorb End Amps To adjust the set points in the Absorb End Amps screen: 

     ADVANCED MENU

  Absorb End Amps

                  00 A

EXIT  NEXT    -    + 

1. Navigate to the Absorb Time Limits screen through the 

ADVANCED MENU as instructed in Figure 35. 

2. Use < -> or < + > to adjust the Absorb time from 0.0 to 24.0 hours

following the recommendation of the battery manufacturer.  

3. Press <NEXT> to advance to the Absorb End Amps screen. 

 

To Exit:

o Press <EXIT> once to return to the main menu.

o Press <EXIT> twice to return to the status screen. 

1. Navigate to the Absorb End Amps screen through the 

ADVANCED MENU as instructed in Figure 35. 

2. Use < -> or < + > to adjust the amperage limit following the

recommendation of the battery manufacturer.  The default value

is 00. 

3. Press <NEXT> to advance to the Rebulk Voltage screen. 

 

To Exit:

o Press <EXIT> once to return to the main menu.

o Press <EXIT> twice to return to the status screen. 

Figure 41 Absorb End Amps Screen  

 

Rebulk Voltage (Advanced Menu)   

In the Float stage, if the battery voltage falls below the ReBulk Voltage set point for at least

90 seconds, the FLEXmax will automatically initiate a new charge cycle.  

Figure 42 Rebulk Voltage  

Vbatt Calibration (Advanced Menu)     

A quality, calibrated voltmeter will provide even more accurate FLEXmax battery readings if an

undesirable voltage drop occurs.  When measuring battery voltage, ensure a good connection is

made to the four wire lugs.  Check the battery temperature compensation voltages if the

voltages are much different than expected from the charger setup Absorbing and Float

voltage settings.  

  

Adjusted

Voltage

Rebulk Voltage

To adjust the set points in the Rebulk Voltage screen: 

     ADVANCED MENU

    Rebulk Voltage

                 12.0V

EXIT  NEXT    -    + 

Vbatt Calibration

To adjust the set points in the Vbatt Calibration 

     ADVANCED MENU

   Vbatt Calibration

14.1 V           0.0 V

EXIT  NEXT    -    + 

NOTE:  The adjusted voltage value

should appear on the status screen. 

1. Navigate to the Rebulk Voltage screen through the 

ADVANCED MENU as instructed in Figure 35. 

2. Use < –> or < + > to adjust the voltage limit  following the

recommendation of the battery manufacturer.   The default

values are 12.0 V, 24.0 V, 36.0 V, 48.0 V and 60.0 V. 

Adjustment

Value  

RTS Compensation (Advanced Menu)    

The RTS Compensation screen allows the user to control the Absorbing and Float voltage

limits during charging when using a Remote Temperature Sensor (RTS).  The RTS adjusts 

charging voltage depending on battery temperature.  (See page 99 for the amount of

compensation per degree.)  However, some conditions can make compensation less than

optimal, such as extreme weather (hot or cold), or charging restrictions from the battery

manufacturer.  Therefore, the RTS Compensation screen allows the user to control the limits

used by the compensation feature.   

Operation

 

3. Press <NEXT> to advance to the Vbatt Calibration screen. 

 

To Exit:

o Press <EXIT> once to return to the main menu. 

o Press <EXIT> twice to return to the status screen. 

screen:

1. Navigate to the Vbatt Calibration screen through 

the  ADVANCED MENU as instructed in Figure 35.

2. Use < -> or < + > to increase or decrease the value. 

The voltage will change in increments of 0.1 Vdc.

3. Press <NEXT> to advance to the 

 

RTS Compensation screen. 

To Exit: 

o Press <EXIT> once to return to the main menu.

o Press <EXIT> twice to return to the status screen. 

 

 

Operation

 

For example: 

o

 During cold weather, a battery often requires a higher charging voltage.  Some inverters might not

accommodate these voltages and can shut down during charging, cutting off power to their loads.    

o

 During hot weather, limiting the RTS Compensation values assures the voltage stays high enough to

charge the batteries instead of dropping too low in reaction to a higher ambient temperature. 

o

 Battery manufacturer specifications indicate not to exceed a certain voltage or battery damage

could occur. 

In all cases, the batteries should be monitored to ensure they are being charged according to

the battery manufacturer’s recommendations. 

RTS Compensation has two options available.   

o

 WIDE allows the RTS full control over charging.  This option uses the default values for the RTS.

o

  LIMIT sets the minimum and maximum voltages for the RTS. 

Pressing the soft key below each option switches between the two options.  When the LIMIT

option is visible, a <SET> soft key is available to advance to a screen that allows the user to 

adjust the settings. 

 

RTS Compensation 

     ADVANCED MENU

   RTS Compensation

A 14.1 V      F 13.8 V

EXIT  NEXT  WIDE 

Press <WIDE> to

switch to LIMIT. 

     ADVANCED MENU

   RTS Compensation

A 14.1 V      F 13.8 V

EXIT  NEXT  LIMIT  SET 

Press <LIMIT> to

switch back to WIDE. 

     ADVANCED MENU

   RTS Compensation

A 14.1 V      F 13.8 V 

EXIT  NEXT  LIMIT  SET 

RTS COMPENSATION

Upper LIMIT   14.1 V

Upper LIMIT     14.1 V

BACK        -    + 

To use the default RTS compensation values:

1. Navigate to the RTS Compensation screen through the 

ADVANCED MENU as instructed in Figure 35.

2. If WIDE is visible above the soft key, the absorb and float values  




 

shown in this screen will be used by the system. 

To Exit:

o Press <NEXT> to  advance to the Auto ReStart menu.

o Press <EXIT> once to return to the main menu.

o Press <EXIT> twice to return to the status screen. 

To limit the RTS compensation values:

1. Navigate to the RTS Compensation screen through the 

ADVANCED MENU as instructed in Figure 35.

2. If WIDE is visible above the soft key, press the <WIDE> soft key to 

change the display to show LIMIT.

3. Press <SET> to advance to the RTS COMPENSATION limits screen. 

o Press < > until the   is next to the limit to be changed.  

The    will switch between the upper and lower limit values each  

time it is pressed.

o Press <-> to decrease the value.

o Press <+> to increase the value. 

To Exit:

o Press <BACK> to return to the main RTS Compensation screen.

o Press <EXIT> once to return to the main menu.

o Press <EXIT> twice to return to the status screen. 


Auto ReStart (Advanced Menu)    

This setting allows the user to choose between continuous maximum power point (MPP)

tracking, or occasional restarts of the sweeping process.  A restart means the controller

abandons the existing maximum power point value it was using and “re-sweeps”, or begins

gathering new power point data.  (See page 97 for more information on MPP tracking.)  

Auto ReStart has three options available: 

o Mode 0 – Initial sweep only and then continuous MPP tracking.  Auto ReStart is disabled.  

The FLEXmax will continously track the maximum power point without starting over. 

o Mode 1 – Automatic re-sweep every 90 minutes if controller is in an MPPT mode (MPPT Float,

MPPT Bulk, etc).  This will not reset any counters, charging stages, or statistics. 

o  Mode 2 – Automatic re-sweep every 90 minutes if controller is in any charging mode.  This will not

reset any counters, charging stages, or statistics. 

 

 

Auto ReStart Screen To select an Auto ReStart mode:

1. Navigate to the Auto ReStart screen through the 

     ADVANCED MENU

     Auto ReStart

        MODE 0

EXIT  NEXT        MODE 

     ADVANCED MENU

     Auto ReStart

        MODE 1

EXIT  NEXT        MODE 

     ADVANCED MENU

     Auto ReStart

        MODE 2

EXIT  NEXT        MODE 

     ADVANCED MENU

     Auto ReStart

        Mode 0

EXIT  NEXT        MODE 

 

Operation

 

2. Press <MODE> to switch between the three Auto ReStart

modes: MODE 0 (default), MODE1, and MODE2. 

To Exit:

o Press <NEXT> to advance to the Aux Polarity screen.

o Press <EXIT> once to return to the main menu.

o Press <EXIT> twice to return to the status screen.

 

 

Operation

 

Aux Polarity (Advanced Menu)      

When the AUX function is ON, 12 volts DC is present at the AUX terminals (Active High).  When

the AUX function is OFF, 0 volts DC are present at the terminals (Active Low).   

Aux Polarity allows the user to reverse the availability of this voltage for the Night Light, PV

Trigger, or Diversion Relay functions.   When one of these functions has been chosen as the

AUX function, an arrow in the right hand corner of the screen will reflect the Aux Polarity state.  

o In Active High, the user establishes certain conditions for these functions.  

o In the Active Low, zero voltage will be available for a function that in Active High would normally 

have voltage.  

Aux Polarity Screen To select the mode for Aux Polarity:

1. Navigate to the Aux Polarity screen through the  

     ADVANCED MENU

    Aux Polarity

      Active High

EXIT  NEXT        MODE 

     ADVANCED MENU

    Aux Polarity

      Active Low

EXIT  NEXT        MODE 

Reset to Defaults?      

     ADVANCED MENU

  Reset to Defaults?

 

EXIT  NEXT       RESET 

Figure 46 Aux Polarity Screen 

Reset to Defaults?  To exit the Reset to Defaults menu without resetting the

charge controller: 

     Are you Sure?

   Reset to Defaults


 YES               NO 

     ADVANCED MENU

  Reset to Defaults?


EXIT  NEXT       RESET 

o Press <EXIT> to return to the main menu.   

o Press <EXIT> again to return to the status screen.  

This will exit the menu without making any changes to the current settings. 

 

ADVANCED MENU as instructed in Figure 35.

2. Press <MODE> to switch between: 

 

 Active High or  Active Low 

To Exit:

o Press <NEXT> to advance the Reset to Defaults? screen.

o Press <EXIT> once to return to the main menu.

o Press <EXIT> twice to return to the status screen. 

AUX MODE 

(Active Low) 

       AUX MODE     

      PV Trigger

Output: Off        OFF

EXIT  NEXT  SET   MODE 

To reset the FLEXmax to factory default settings:

1. Press <RESET>. 

2. Press <YES> to confirm the reset.  Upon the next power-up, the 

FLEXmax will prompt the user to confirm the voltage (see page 18).

3. Press <EXIT> twice to return to the main menu. 

4. Press <NEXT> to return to the beginning of the ADVANCED MENU

(see page 49).   

This procedure is recommended any time the controller is relocated or the

system is substantially revised.  The settings can also be reset to the

defaults by performing a reboot (see page 60). 


AUX MODE

(Active High) 

       AUX MODE     

      PV Trigger

Output: Off        OFF

EXIT  NEXT  SET   MODE  

Logging        

The Logging screen in the main menu enables the user to clear the daily and cumulative logs 

if necessary.  Logs can be downloaded to an SD card if a MATE3 or MATE3s is installed. 

See page 71 for details. 

The FLEXmax daily log begins when the controller enters Wakeup.  See page 26. 

 


IMPORTANT:   

If two or more charge controllers are used in the same system and are started up or cleared

on different days, their numeric dates will not be the same. This can lead to some

misunderstandings when looking back and comparing data between the two or more units.  A

user looking back at day 12 on both units would find very different results. 

Main Menu 

 Charger Aux  Light

  EQ    Misc  Advanced

    Logging  Stats 

EXIT          GO 

Charger  Aux   Light

  EQ    Misc  Advanced 

 Logging  Stats

EXIT          GO 

End-of-Day

Summary Screen 

Today  000Ah   00.0kWH

011Vp  00.0Ap  0.00kWp

MAX 14.7 V   ABS 01:00

MIN 14.6 V   FLT 00:00 


       CLEAR LOG


BACK  TOTL  DAILY 


     Are you Sure?

 

 NO               YES 

To clear the logs:

1. From the main menu, press <> to move the arrow 

next to Logging.

2. Press <GO> to advance to the End-of-the-Day 

Operation

 

summary screen.

3. Press the second soft key (SK2) to bring up the CLEAR 

Log screen.  The CLEAR LOG screen offers the option

of clearing up to 128 days of accumulated statistics or

the total in the secondary STATS screen (page 59).  

4. Press and hold either <TOTL> (total) or <DAILY> 

to clear those specific statistics. The Are you sure? 

screen appears.

5. Pressing <YES> returns to the CLEAR LOG screen; 

pressing <NO> returns to the Logging screen.

6. Press <BACK> to return to the End-of-Day 


 

summary screen. 

Pressing SK3 and SK4 changes the displayed

day’s statistics, by moving either forward or

backward within the 128 days of available statistics

that are viewable. 

Today  000Ah   00.0kWH 

011Vp  00.0Ap  0.00kWp

MAX 14.7 V   ABS 01:00

MIN 14.6 V   FLT 00:00 

 

Operation

 

Stats      

The STATS screen in the main menu displays additional voltage and time information.  In a stand-alone FLEXmax

controller — one that is not connected to a system display — Sunrise shows how long ago the FLEXmax woke up for

the first time each day and when the daily and total logged values were updated and cleared.  If the FLEXmax is

connected to a system display, the logging occurs at midnight. 

Main Menu 

 Charger Aux  Light

  EQ    Misc  Advanced

    Logging  Stats 

EXIT          GO 

Charger  Aux   Light

  EQ    Misc  Advanced 

   Logging  Stats

EXIT          GO 

Max Bat  Voc    MaxVoc

14.9     036.6  133.0

MaxWatt  0000  Sunrise

EXIT  NEXT    01:30:33 

Max Bat  Voc    MaxVoc

14.9     036.6  133.0

MaxWatt  0000  Sunrise

EXIT  NEXT    01:30:33 

Max Bat  Voc    MaxVoc

14.9     036.6  133.0

MaxWatt  0000  Sunrise

EXIT  NEXT    01:30:33 

Max Bat  Voc    MaxVoc 

14.9     036.6  133.0

MaxWatt  0000  Sunrise

EXIT  NEXT    01:30:33 

Max Bat  Voc    MaxVoc

14.9     036.6  133.0

MaxWatt  0000  Sunrise

EXIT  NEXT    01:30:33 

Max Bat  Voc    MaxVoc

14.9     036.6  133.0

MaxWatt  0000  Sunrise

EXIT  NEXT    01:30:33 

To view the STATS screen:

1. From the main menu, press <> to move the 

arrow next to STATS.

2. Press <GO> to advance to the statistics screens.  

Maximum historical battery voltage

occurring on the FLEXmax.  

 

o The daily high V value. 

o The highest historical V valueoccurring on the FLEXmax. 

o The maximum wattage seen by the FLEXmax. 

o The time the logs were cleared and reset. 

Press <NEXT> to view the second STATS screen.  

Viewing the Firmware Revision   

The current firmware revision of the FLEXmax controller can be viewed on its own screen. 

Status Screen

Return to the main menu screen.  

From the status screen, press the

first soft key (SK1) to open the main

menu screen. 


From the main menu screen, press  

and hold <EXIT> (SK1).  As long

as SK1 is held, it will show a 

Revision screen with the current

firmware revision of the FLEXmax. 

 

Secondary STATS 

Total  00000   kWH

Total  0000.0  kAH


BACK        DCkWH 

Total  00000   kWHAC

Total  0000.0  kAH


BACK        ACkW 

Figure 51 Firmware Revision Screen 

Extended Play Mode   

If the MPP voltage is low enough to approach the battery voltage (usually when the PV array is

very hot), it is near the effective limit of the MPPT function.  Side effects may cause the

FLEXmax components to make a squealing noise.  Extended Play mode alleviates this problem

by extending the parameters of the MPPT sweep.    

To activate or deactivate the Extended Play feature: 

Revision Screen

Follow the instructions in Figure 51 

for reaching the Revision screen.

While continuing to hold SK1, press 

and hold SK3.  After a few seconds, 

the screen will toggle the status of

Extended Play and display it.  

X on means the mode is on.  

If necessary, continue to press  

and hold SK3 until it reads X on. 

The Secondary Stats screen shows the total accumulated DC and

AC kilowatt-hours and kiloamp-hours of the charge controller. 

Pressing the <DCkWH> soft key switches the screen between

DC kilowatt-hours and AC kilowatt-hours. 

DCkWH

 shows the DC kilowatt-hours and should be used in a

system that is not grid-interactive. 

In   113.6V   0.0 A

Out   12.5V   0.0 A

    0.000 kW  0.0 kWH

AUX: OFF      Sleeping 

ACkWH

 is used with a grid-interactive system.  This measure is

based on a 90% inverter efficiency (1 kWh DC= 0.9 kWh AC). 

Pressing the <BACK> key three times returns to the main menu.  

Charger  Aux   Light

  EQ    Misc  Advanced

  Logging    Stats 

EXIT          GO 

002.001.000 

Extended Play Screen 

002.001.000

  

Main Menu 

X on

  

To deactivate, repeat the process until the screen reads X off. 

 

 

 

Operation

 

Rebooting the FLEXmax  

   

 

If the screen becomes garbled or the FLEXmax controller otherwise will not respond to

commands, it may be necessary to reboot its internal processor. 

 

 


IMPORTANT:   

Rebooting the FLEXmax controller will return all the values and set points to the factory

defaults.  These values are listed on page 96.  It is advisable to record all custom values

before rebooting. 

To reboot the FLEXmax:

1. Turn off the battery and PV array circuit 

breakers.  The FLEXmax should have

no sources of power connected. 

Observe the screen until it goes blank. 

2. Press and hold the first and third soft

keys (SK1 and SK3). 

3. While holding down these soft keys,

switch on the battery circuit breaker. 

This process follows the power-up

sequence shown on page 17.  Continue 

to follow the Select Version screen

instructions from the beginning of

the manual.  

 

DC Circuit

Breakers  

SK1 and SK3 

 

 

MATE3-class System Display 

and Controller  

This section covers the use of both the MATE3 and MATE3s products.  A MATE3-class system

display provides the means for programming the FLEXmax charge controller and other devices

when preprogrammed default settings do not work for the destined installation. 

 

Display and LED Status Indicators 

Inverter LED

Charger LED

Generator LED

Battery Status LEDs (×3)

LCD Screen 


Events LED 

AC Input LED 

Favorite LED 

 

 

 

 

MATE3-Class Screens

 

Charge Controller Soft Key   

Charge Controller Soft Key

Press this soft key to view FLEXmax 

charge controller status information. 

If no charge controller is present, the

PV icon will be blank and this soft

key will be inoperative. 

Charge Controller Modes:

o Bulk  

o Absorb 

o Float 

o EQ  

o Silent 

 

The FLEXmax has over 25 modes.  The

system display can only display five status

messages and may substitute one of the five

for a FLEXmax mode not on this list.  Check

the FLEXmax status screen to determine its

exact mode. 

 See page 22 for a description of modes.

 See page 98 for a description of  

battery charging.   

PV Icon 

Soft Keys:

<Datalog> brings up a group of charge 

controller statistics that are maintained as

a continuous daily log.  These screens are

all shown beginning on page 63.   

<Graph> brings up a series of screens

that plot various charge controller 

information over time.  The graphs include

inverter and charger wattage, power

imported from an AC source, battery

voltage, and others.  These screens are all

shown beginning on page 64.   

<Port> cycles through each device

connected to the network.  If more than 

one charge controller is installed in the

system, pressing the <Port> soft key will 

cycle through each controller.

<Back> returns to the previous screen. 

Charge

Controller’s Mode 

Screen Items:

The upper left corner of the screen shows the FLEXmax 

charge controller’s current mode of operation.  Bulk is shown

in this illustration.   

In displays the present PV array operating voltage and the

current being harvested from the array. 

VOC displays the open-circuit voltage available from the PV.

Out  displays the present battery voltage and the current 

being delivered from the charge controller(s) to charge the

battery bank.  To the right, this line displays the number of

kilowatt-hours and amp-hours accumulated that day. 

Operating displays the total hours the charger has operated

that day in any stage. 

Float displays the run time of the Float timer when in the

Float stage.  

Absorb displays the run time of the timer when in the

Absorbing stage.  

Maximum displays the maximum amperage and wattage

harvested from the PV array that day, and the time both were

recorded. 

The lower right corner shows the current status of the charge

controller’s Auxiliary (AUX) output.  (See page 68.)  

DataLog Screen   

MATE3-Class Screens

 

The <DataLog> soft key shows accumulated daily amp-hour and watt-hour statistics, as well

as maximum current, wattage, and maximum and minimum voltage figures.  These maintain a 

continuous daily log, up to 128 days, which can be recalled.  One day can be displayed at a

time.  See page 58 for more information. 


Current Date

Screen Items: 

Soft Keys:

<+Day> advances the display forward by 

a single day.  If the display reads “Today”,

it does nothing. 

<–Day> advances the display backward

by a single day and will display the 

selected date.

<Back> returns to the previous screen.  

<Port> cycles through each device

connected to the network. 

The upper left corner shows the date of the

selected Datalog screen.  (The current Datalog

screen reads "Today.")  To the right, this line

also displays the kilowatt-hours and amp-hours

accumulated that day. 

Max Output displays the maximum current and

wattage recorded that day. 

Absorb  The amount of time the Absorbing timer

ran that day. 

Float  The amount of time the Float timer ran

that day.  

High VOC displays the highest open-circuit

voltage (V

OC

) recorded that day. 

Min Batt  displays the lowest battery voltage

recorded that day. 

Max Batt  displays the highest battery voltage

recorded that day. 

 

MATE3-Class Screens

 

Graph Screens  

The <Graph> soft key brings up the following screens which plot various type of data over

time.  The first screen shows changes in PV wattage over time.  

 

This axis shows date and

time in 6-hour increments. 

Figure 57 Output Graph  

The <Next> soft key brings up a screen showing changes in battery voltage over time.   

This axis shows date and

time in 6-hour increments. 

Figure 58 Battery Graph  

The <Next> soft key brings up a screen showing changes in PV voltage over time.  

This axis shows date and

time in 6-hour increments. 

Figure 59 PV Graph  

Continuing to press the <Next> soft key will proceed through the same graphs again from 

the beginning. 

This axis shows

PV wattage. 

This axis shows

battery voltage. 

This axis shows

PV voltage. 


MATE3-Class Screens

 

Menu Structure in the MATE3 and MATE3s     

Figure 60 shows the menu structure for adjusting the FLEXmax charge controller settings. 

Figure 60 Menu Structure 

The Main Menu shown above is accessed with the LOCK button and a password.  Use the 

control wheel on the system display to move up and down between menus (or options within 

a menu).  Use the center button on the control wheel to make a selection.  (See the system

display literature for more information.) 

Some menus may not be accessible if the user access levels are restricted.  


MATE3-Class Screens

 

Charge Controller Settings  

Charge Controller menu options include the following: 

Charger ------------------------------------------------------- >

See below. 

MPPT ---------------------------------------------------------- >

See below. 

Temperature Compensation --------------------------- >

See page 67. 

Battery Equalize -------------------------------------------- >

See page 67. 

Grid-Tie Mode  ---------------------------------------------- >

See page 67. 

Auxiliary Output -------------------------------------------- >

See page 68. 

Restart Mode ------------------------------------------------ >

See page 69. 

Calibrate ------------------------------------------------------ >

See page 70. 

Reset Charge Controller to Factory Defaults ----- >

See page 70. 

Charger 

 

 

   

IMPORTANT:   

Battery charger settings need to be correct for a given battery type.  Always follow battery manufacturer

recommendations.  Making incorrect settings, or leaving them at factory default settings, may cause the

batteries to be undercharged or overcharged. 

The charge controller uses a “three-stage” battery charging cycle which utilizes multiple

settings.  This menu controls the voltages and timers for the battery charger.  See page 98 for

an explanation of the three-stage cycle and a description of the individual stages.  

MPPT 

 

Set Points: 

o Absorb Voltage  

o (Absorb) Time

o Float Voltage   

Charger 

The charge controller uses a maximum power point tracking (MPPT) algorithm which

manipulates the output of the PV array to harvest maximum wattage.  Although this function is

automatic, this menu allows the user to adjust many of its parameters for special applications. 

See pages 50, 51, and 102. 

Set Points:

o MPPT Mode  

o U-Pick VOC  

o Wakeup VOC Change VDC and Wakeup VOC 

Change Time – The FLEXmax screen refers to 

these items under the title “Wakeup Mode” 

o Snooze Mode Amps 

o MPP Range Minimum and MPP Range Maximum  

– The FLEXmax screen refers to these items under

the title “Mpp Range Limit %” 

 MPPT  

o Rebulk Voltage  

o Current Limit  

o Absorb End Amps   

Temperature Compensation

    

MATE3-Class Screens

 

When equipped with the Remote Temperature Sensor (RTS), the charge controller

compensates for temperature changes by raising or lowering its charging voltages.  However, in

some cases the sensitivity of other DC devices may require this temperature compensation to

be limited.  This menu allows the user to manually adjust the upper and lower limits of

temperature compensation.  See page 99 for an explanation of compensation.  See page 53 for

the FLEXmax RTS Compensation menu. 

Temperature Compensation 

Battery Equalize 

CAUTION:  Battery Damage 

 Do not equalize any sealed battery types (VRLA, AGM, Gel, or other) unless approved by the

manufacturer.  Some batteries may suffer severe damage from equalization. 

 Contact the battery manufacturer for recommendations on equalization voltage, duration, schedule,

and/or advisability.  Always follow manufacturer recommendations for equalization.   

This menu controls the settings for the equalization process, which is used for battery

maintenance.  See page 45 for an explanation of equalization and how it relates to the regular

charging process.  

Grid-Tie Mode 

 

 Battery Equalize 

  

IMPORTANT:   

Set Points:

o Mode 

o Limited:  Lower Battery Voltage  

o Limited:  Upper Battery Voltage

The FLEXmax menu features these items as options under 

“RTS Compensation.” 

Set Points: 

o Equalization Voltage 

o (Equalization) Hours 

o Automatic Battery Equalization     

This mode requires a grid-interactive inverter model (also known as grid-tie enabled).   Not all

inverters are grid-interactive.  If the system is connected to an inverter that is not grid-

interactive, Grid-Tie mode will not function if selected. 

This menu allows the charge controller to work more effectively with any grid-interactive

inverters present on the HUB.  See pages 47, 51, and 104 for more information. 

Set Points:

o Two options are available in this menu; N and Y: 

 N (No) disables Grid-Tie Mode; 

 Y (Yes) enables Grid-Tie Mode 

MATE3-Class Screens

 

Auxiliary Output (Charge Controller) 

This menu controls the output and functionality of the Auxiliary (AUX) output.  The charge

controller’s AUX terminals provide a 12 Vdc output that can deliver up to 0.2 Adc to control

external loads.  Typical loads include signaling a generator to start, sending a fault alarm signal,

or running a fan to cool the inverter.  See page 13 for an image of the AUX terminals.  See

page 30 for a description of AUX modes.  

Figure 66 Auxiliary Output 

Aux Modes for the Charge Controller 

Aux Modes include nine options with automatic criteria.  The options appear in the following

order when the wheel is drawn clockwise.  The Vent Fan option appears first if the charge

controller is set at factory default values; otherwise, it will tend to display the last option

selected.  (The options are described in greater detail beginning on page 32.) 

NOTE:  The Remote option allows a MATE3-class system display to use the AUX output for

AGS (see page 44).  AGS is intended for systems with a HUB, inverter, and FLEXmax.  If the 

system display connects only to a FLEXmax, AGS will only work with DC Genset programming. 

The other AGS functions will not work properly. 

Vent Fan 

Set Points:

o Status – The Auxiliary Output status is controlled by the 

<Off>, <Auto>, and <On> soft keys.  

o Aux Mode –Selects one of nine options:  Vent Fan, PV 

Trigger, Error Output, Night Light, Float,

Diversion:Relay, Diversion:Solid St, Low Battery

Disconnect, and Remote. 

Set Points: 

o Enable Voltage  

Figure 67 Vent Fan 

PV Trigger 

Set Points:     

o Enable Voltage  

o Hold Time  

o Active:  High or Low.    

Figure 68 PV Trigger

Error Output 

Set Points: 

o Low Battery Voltage  

Low Batt Disconnect 

Remote 

Set Points: 

o Active:  High or Low.    

o Threshold 

o Hysteresis Time

o ON Time   

Set Points:   None 

Set Points  (NOTE:  All items function identically for both

Diversion: Relay and Diversion: Solid St, except for Active:  

High or Low):

o Active:  High or Low.  (Not present in Diversion: Solid St)

o Relative Voltage 

o Hysteresis 

o Hold 

o Delay 

Set Points:

o Disconnect  

o Re-Connect  

o Disconnect Delay   

Figure 73 Low Batt Disconnect 

Set Points:  None

This mode can also be used for the AGS function.  See pages 

44 and 68 for important information on this function. 

Restart Mode    

This item selects between continuous MPPT, or occasional restarts.  (See pages 23 and 55.) 

Set Points:

o 0 – Continuous MPPT, 1 – Automatic re-sweep every 90 

minutes in MPPT charging, 2 – Automatic re-sweep every

90 minutes in any mode. 


MATE3-Class Screens

 

Calibrate     

The Calibrate menu allows adjustment of the charge controller’s battery voltmeter.  If a

particular controller’s readings do not match those of another device, or a hand-held meter, the

calibration feature may improve consistency.   


NOTE:  Calibration does not change the actual voltage of the charge controller, only the

reading of that voltage. 

Also, measurements in places other than the charge controller’s terminals may differ regardless 

of calibration.  For example, it is possible to get a different reading at the charge controller’s DC

terminals than on the batteries.  Connection problems, corrosion, and the effects of induction

and resistance may all result in voltage differences.  If this occurs, note that this is an issue with

the system, not the charge controller.  Calibration cannot correct for it. 

Reset Charge Controller to Factory Defaults   

This menu allows the user to erase all settings from the selected charge controller and start

over with the values programmed at the factory.  These values are listed on page 96. 

To access the Reset to Factory Defaults menu:

1. Access the main menu as shown in Figure 16. 

2. Select the Settings menu.  (This option may be

highlighted by default.) 

3. Select Charge Controller in the device Settings menu.

4. Select the Reset to Factory Defaults menu.  

5. Use the soft keys to select No or Yes. 

 If <No> is selected, the screen returns to the

Charge Controller menu.  No changes will be 

made to any settings. 

 If <Yes> is selected, the inverter’s settings will

immediately change to the original factory values.  

The screen will display the message Charge

Controller Restored to Factory Defaults.    

A <Continue> soft key will appear.  Pressing this

key will return the screen to the Charge Controller 

menu. 

Calibration Offset 

6. After resetting the charge controller to factory default

parameters:  

 press the <Continue> soft key or the Up

navigation key to return to the Charge Controller 

menu, or

 press the Top navigation key to return to the 

Set Points:

o Battery Voltage – Calibrates the Vdc measurement 

 

made at the controller’s battery terminals.    

Settings menu.

Press <Continue> to return to

the Charge Controller  Menu. 


Device Data Logs      

MATE3-Class Screens

 

Users of the MATE3 or MATE3s can create Device Data Logs for the FLEXmax charge

controller.  The Data Logs can then be uploaded and saved to an SD card. 

Saving Data Logs for the FLEXmax Controller 

To create a data log for the FLEXmax Charge Controller:

1. Access the Main Menu as shown in Figure 16.

2. Select the Device Data Logs menu.   

3. Select FLEXmax Charge Controller menu.

4. Select Upload and Save Data Log on the FM Charge 

Controller Data Log menu.

5. Select one of the two options. 

 Press <New> to give the new data log a unique

name.  Or  

 Press <Save> to save the data log over the name

that is highlighted on the list. 

6. After saving the data log is complete, press <Continue>

to return to the Upload and Save Data Log screen. 

To save a new data log over the name highlighted on the list:

1. Use the control wheel to scroll through the list.  

2. When the name to be replaced is highlighted, press 

<Save>.

3. Wait for the message confirming that the profile has been 

saved to the SD card.

4. Press <Continue> to return to the Upload and Save 

Data Log menu. 

To create a new name for the data log (up to 8 characters 

maximum):

1. Use the control wheel to scroll through the available 

characters.  

2. Use <> and <> to move to the next character location. 

3. Press <Delete> to erase the character that is highlighted.

4. Press <Save> to save the new data log on the SD card. 

4. Press <Continue> to return to the Upload and Save 

Data Log menu.

 

Returns to the Upload and

Save Data Log screen. 

Returns to the Upload and Save

Data Log screen. 

Figure 78 Uploading and Saving a Data Log for the FLEXmax 

900-0009-01-00 Rev D 71 

 

 

MATE3-Class Screens

 

Data Log File Format 

Information generated by this function will be saved on the SD card in a generic .csv file format,

which can be read by most spreadsheet programs. 


Data Logging example: 


 

NOTE:  This header line is NOT included in the download. 

Date AH Kwh

Max

Amps 

Max

Watts 

Absorb

Time 

Float

Time 

Min

Battery V  

MATE-Class System Display

and Controller 

This section covers the use of both the MATE and MATE2 products.   

Summary Screens 

If a FLEXnet DC (FN-DC)

is installed in the system,

the following summary

screens will be available. 

FLEXnet DC

Summary Screen #1 

FLEXnet DC

Summary Screen #2 

FLEXnet DC

Summary Screen #3 

FLEXnet DC

Summary Screen #4 

(If the FN-DC is not

installed, this will be the 

first Summary Screen.) 

Figure 80 Summary Screens 

FX Inverter/Charger

Summary Screen 

FLEXmax Charge Controller

Summary Screen  


MATE-Class Screens

 

Status Screens 

To view the status screens of a FLEXmax 60 or FLEXmax 80 using a MATE, follow the

illustration below.  Changes to FLEXmax settings can only be changed from the charge

controller user interface; changes can not be done when viewing these screens on a MATE. 

MODE Screens 

MAIN------------------

1:35:04p 


SUM  STATUS  SETUP ADV 

STATUS----------------

choose device


 FX    CC    DC   MAIN 

STATUS/CC/PAGE1



MODE METER  SETPT PG2 

STATUS/CC/MODE-----P00

charger mode:   Silent


DOWN       STATUS PORT 

STATUS/CC/MODE-----P00

aux relay mode:

        Low Batt

DOWN   UP   TOP   PORT 

STATUS/CC/MODE-----P00

aux relay state:    ON

        

DOWN   UP   TOP   PORT 

STATUS/CC/MODE-----P00

End of mode menu 


   o    UP   TOP STATUS 

Navigation for STATUS/CC/MODE 

 < STATUS > returns to the STATUS/CC/PAGE1 screen.


o DOWN

> moves to the next menu item in the diagram.

o UP

> moves to the previous menu item in the diagram.

o TOP

> returns to the first CC/MODE screen for the  

port shown. 

o PORT

> directs the system display to read the next

device (port) on the HUB. 

Charge Controller Modes 

The MODE screens describe the current operating mode

for the FLEXmax charger (see page 22) and AUX output

(see page 30). 

The FLEXmax has over 25 modes.  The MATE can only

display five status messages and may substitute one of the five

for a FLEXmax mode not on this list.  Check the FLEXmax

status screen to determine its exact mode. 

charger mode:    

o Bulk 

o Absorption 

o Float 

o Silent 

o Equalization 

aux relay mode:   

o vent fan 

o pv trigger 

o error output 

o night light 

o float 

o diversion: relay 

o diversion: solid st 

o low battery disconnect 

o remote aux relay state:  

This screen indicates if the AUX output is  

o ON

o OFF 

 

METER Screens 

MAIN------------------

1:35:04p 


SUM  STATUS  SETUP ADV 

STATUS----------------

choose device


 FX    CC    DC   MAIN 

STATUS/CC/PAGE1



MODE METER  SETPT PG2 

mode: Silent       P00

in  11.2 vdc     0 adc

out 14.4 vdc     0 adc

 DOWN      STATUS PORT 

STATUS/CC/METER----P00

charger            0 w

watts

DOWN   UP   TOP   PORT 

STATUS/CC/METER----P00

charger        0.0 kwh

kwhrs

DOWN   UP   TOP   PORT 

STATUS/CC/METER----P00

charger       +000 Adc

amps DC

DOWN   UP   TOP   PORT 

STATUS/CC/METER----P00

charger           0 ah

amp hour

DOWN   UP   TOP   PORT 

Figure 82 METER Screens 

MATE-Class Screens

 

o Navigation for STATUS/CC/METER < STATUS > returns to the CC/PAGE1 screen.


DOWN

> moves to the next menu item in the diagram.

 <

UP

> moves to the previous menu item in the diagram.

 <

TOP

> returns to the first CC/METER screen for the 

port shown.

 <

PORT

> directs the system display to read the next 

device (port) on the HUB. 

Charge Controller METER Screens 

The METER screens display readings for power, current,

and voltage handled by the FLEXmax.  (See page 74 for

more information on the mode messages displayed here.) 

mode/pv-in/bat-out:   

 mode (charger )

 Bulk 

 Absorption 

 Float 

 Silent 

 Equalization 

charger watts: Charger output to the battery (watts). 

charger kwhrs: Kilowatt-hours sent to the batteries today. 

charger amps dc: Charger current to the battery (Adc). 

battery voltage:  Battery voltage (Vdc).

panel voltage:  PV array voltage (Vdc).

CC Firmware revision:  The level of the last revision or 

programming upgrade to the FLEXmax. 

STATUS/CC/METER----P00

battery       13.7 Vdc

voltage

DOWN   UP   TOP   PORT 

STATUS/CC/METER----P00

panel           33 Vdc

voltage

DOWN   UP   TOP   PORT 

o

 in vdc (PV array voltage)

o

 adc (incoming PV current)

o

 out vdc (battery voltage)

o

 adc (outgoing current 

delivered to the battery) 

STATUS/CC/METER----P00

CC Firmware revision    

      002.001.000

DOWN   UP   TOP   PORT 

STATUS/CC/METER----P00

End of meter menu


       UP   TOP STATUS  

 

MATE-Class Screens

 

SETPT Screens 

 

 





 

MAIN------------------

       1:35:04p


SUM  STATUS  SETUP ADV 

STATUS----------------

choose device


 FX    CC    DC   MAIN 

STATUS/CC/PAGE1



MODE METER  SETPT PG2 

STATUS/CC/SETPT----P00

absorb        14.4 Vdc


DOWN STATUS       PORT 

STATUS/CC/SETPT----P00

float         13.6 Vdc


DOWN   UP   TOP   PORT 

STATUS/CC/SETPT----P00 

end of set point

menu

       UP   TOP STATUS 

Navigation for STATUS/CC/SETPT 

o

 <

STATUS

> returns to the CC/PAGE1 screen.

o

 <

DOWN

> moves to the next menu item in  

the diagram.

o

 <

UP

> moves to the previous menu item in  

the diagram.

o

 <

TOP

> returns to the first CC/SETPT screen for 

the port shown.

o

 <PORT> directs the system display to read the 

next device (port) on the HUB. 

Charge Controller SETPT 

(set point) Screens 

The SETPT screens display the current settings for the

FLEXmax battery charger, as described on page 29. 

o

 Absorb

o

 Float  

 

LOG Screens

  

MAIN------------------

       1:35:04p


SUM  STATUS  SETUP ADV 

STATUS----------------

choose device


 FX    CC    DC   MAIN 

STATUS/CC/PAGE1 

 


MODE METER  SETPT PG2 

STATUS/CC/PAGE2-------



 PG1  LOGS  STAT  MAIN 

STATUS/CC/LOG1-----P00

TODAY   0 AH  00.0 kWH

 21Vp  00.0Ap  0.00kWp

DOWN  DAY-  DAY+  PORT 

STATUS/CC/LOG2-----P00

TODAY     battery

max 14.5V    min 14.4V

DOWN  DAY-  DAY+  PORT 

STATUS/CC/LOG3-----P00

TODAY    absorb  float

         00:00   00:00

DOWN  DAY-  DAY+  PORT 

STATUS/CC/METER----P00

end of cc logs display 


 TOP       STATUS 

MATE-Class Screens

 

Navigation for STATUS/CC/LOGS 

o

 <

STATUS

> returns to the CC/PG2 screen.

o

 <

DOWN

> moves to the next menu item in 

the diagram.

o

 <

UP

> moves to the previous menu item in 

the diagram.

o

 <

TOP

> returns to the 1st CC/LOG1 screen

for the port shown. 

o

 <

PORT

> directs the system display to read the next device (port) on the HUB. 

o

 <

DAY

–> displays log information from one 

day earlier.  Logs can be displayed from as 

far as 128 days in the past.

o

 <

DAY

+> displays log information from one 

day later.  If the present day is displayed,

then pressing this key will return the log to

128 days in the past. 

Charge Controller Logs 

The LOG screens contain information collected

from the FLEXmax on individual days.  These

logs include daily accumulated amp-hours and

kilowatt-hours, and peak readings for power,

current, and voltage.  It also includes the timers

for the FLEXmax battery charger.  This data 

is the same as that shown on the FLEXmax

End-of-Day Summary screen (see page 20.) 

Log 1 Today:    

o

 AH (accumulated battery amp-hours)

o

 Kwh (accumulated battery kilowatt-hours)

o

 Vp (peak PV voltage) 

o

 Ap (peak PV current)

o

 kWp (peak PV kilowatt-hours) 

Log 2 Today:   

o

 max V (maximum battery voltage)

o

 min V (minimum battery voltage) 

Log 3 Today:  

o

 absorb timer 

o

 float timer 

 

MATE-Class Screens

 

STAT Screens 

MAIN------------------

       1:35:04p


SUM  STATUS  SETUP ADV 

STATUS----------------

choose device


 FX    CC    DC   MAIN 

STATUS/CC/PAGE1



MODE METER  SETPT PG2 

STATUS/CC/PAGE2-------



 PG1  LOGS  STAT  MAIN 

STATUS/CC/STAT-----P00

maximum battery

        15.1 Vdc

DOWN   UP         PORT 

STATUS/CC/STAT-----P00

voc           21.0 vdc

         

DOWN   UP    TOP  PORT 

STATUS/CC/STAT-----P00

max voc       21.0 vdc

         

DOWN   UP    TOP  PORT 

STATUS/CC/STAT-----P00

maximum wattage         

        400 W      

DOWN   UP    TOP  PORT 

Navigation for STATUS/CC/STAT    

o

 <

STATUS

> returns to the CC/PAGE2 screen.

o

 <

DOWN

> moves to the next menu item in  

the diagram.

o

 <

UP

> moves to the previous menu item in  

the diagram. 

o

 <

TOP

> returns to the CC/STAT/PAGE2 

screen for the port shown, with the exception of

the “end of the cc stats” menu.  From the “end” 

menu, the <

TOP

> soft key returns to the 1st CC/STAT screen. 

o

 <

PORT

> directs the system display to read the 

next device (port) on the HUB. 

Charge Controller Stats 

The STAT screens contain historical data for the

FLEXmax, including peak voltages, peak wattage,

and total accumulations.  (See page 58.) 

maximum battery  Vdc:    

voc:

max voc:

maximum wattage:

total kWH DC:

total kAH: 

STATUS/CC/STAT-----P00

total   kWH DC 

          307

DOWN   UP    TOP  PORT 

STATUS/CC/STAT-----P00

total    kAH 

         25.6    

DOWN   UP    TOP  PORT 

STATUS/CC/STAT----P00

end of cc stats menu 

Advanced Menus 

MATE-Class Screens

 

The Advanced menus available in the MATE or MATE2 system display allow any of the

following options: 

o

 Change the settings of the FLEXmax battery charger and temperature compensation

o

 Change the parameters of the FLEXmax MPPT process

o

 Change the settings of the FLEXmax equalization process

o

 Calibrate the FLEXmax meters

o

 Change the settings of the A

UX

 output to run small AC or DC loads

o

 Start a generator using Advanced Generator Start (AGS) Mode (see page 44)

o

 Adjust the settings or functions of other OutBack devices which are connected to the system display 

(see appropriate manuals) 

The following pages detail the MATE, or MATE2, Control Modes.  Please note whenever a 

password is called for, the system password is: 

141 

Accessing the Advanced Menus 

 

MAIN------------------

       1:35:04p


SUM  STATUS  SETUP ADV 

ADV/SETTINGS/WARNING

  changes made could

   adversely affect

  system performance 

ADV/PASSWORD----------

  Enter the password

         132

ENTER  INC  DEC   EXIT 

ADV/PASSWORD----------

  Enter the password

         141 

ENTER  INC  DEC   EXIT 

o

 Press any soft key to advance to

the next screen. 

o

 Press the <

INC

> soft key until

132

 becomes

141

o

 Press <

ENTER

> when the number 141 is

displayed.  This will proceed into the ADV choose 

device menu in the Advanced menu map. 

o

 Press <

EXIT

> to return to the Main Menu without 

changing the password. 

 

MATE-Class Screens

 

CHGR Menu 

Navigation for ADV/CC/CHGR 

o

 <

DOWN

> moves to the next menu

item in the diagram. 

o

 <

INC

> increases the value of the

selection. 

o

 <

DEC

> decreases the value of the

selection. 

o

 <

PORT

> directs the system display

to read the next device (port) on 

the HUB.

o

 <

ADV

> returns to the CC/PAGE1 

screen. 

o

 <

TOP

> returns to the CC/CHGR 

screen.

o

 <

MAIN

> exits the Advanced menus 

and returns to the Main Menu (see

page 79). 

CC/Charger 

The CHGR screens adjust the

same settings that are available on

the Charger screen in the

FLEXmax (see page 29). 

o


output current limit

 

o

 absorb voltage 

o

 float voltage 

Figure 87 ADV Menu for Charging Features    

CC ADVANCED Menu 

CC/Advanced 

MATE-Class Screens

 

The ADVANCED screens adjust the same settings that are available on the Advanced screen

in the FLEXmax (see page 49).  These settings relate to charging, MPPT, temperature

compensation, and calibration. 


 

Navigation for ADV/CC/ADVANCED 

o <DOWN> moves to the next menu item in the diagram.

o <INC> increases the value of the selection.

o <DEC> decreases the value of the selection.

o <PORT> directs the MATE to the next device (port) on the HUB.

o <TOP> returns to the CC/ADVANCED screen.

o <ADV> returns to the CC/PAGE1 screen. 

o <MAIN> exits the Advanced menus and returns to the Main Menu 

(see page 79). 

 

MATE-Class Screens

 

EQ Menu 

 

Navigation for ADV/CC/EQ 

o

 <

DOWN

> moves to the next menu item

in the diagram. 

o

 <

INC

> increases the value of the

selection. 

o

 <

DEC

> decreases the value of the

selection. 

o

 <

PORT

> directs the system display to

read the next device (port) on the HUB. 

o

 <

TOP

> returns to the CC/EQ screen.

o

 <

ADV

> returns to the choose device 

screen.

o

 <

MAIN

> exits the Advanced menus and 

 

 

returns to the Main Menu (see page 79). 

CC/Equalization 

The EQ screens adjust the same settings

that are available on the EQ screen in the

FLEXmax (see page 45).   

o


eq voltage

 

o

 eq time

o

 eq auto eq interval 

Figure 89 ADV Menu for EQ Charging Features  

  

AUX Menu 

 

 

 

 

MATE-Class Screens

 

Navigation for ADV/CC/AUX 

o

 <

DOWN

> moves to the next menu item in 

the diagram. 

o

 <

INC

> increases the value of the selection.

o

 <

DEC

> decreases the value of the selection.

o

 <

PORT

> directs the system display to read 

the next device (port) on the HUB.

o

 <

TOP

> returns to the CC/PAGE2 screen. 

o

 <

ADV

> returns to the choose device screen. 

o

 <

MAIN

> exits the Advanced menus and

returns to the Main Menu (see page 79). 

CC/AUX 

The Aux screens adjust the same settings that

are available on the Aux screen in the FLEXmax

(see page 30).   

Aux mode:

o

 vent fan  

o

 pv trigger 

o

 error output 

o

 night light 

o

 float 

o

 diversion: relay 

o

 diversion: solid st 

o

 low batt(ery) disconnect 

o

 remote 

The remote mode also can be used for the

system display’s AGS function.  See page 44. 

NOTE

:  The AGS function is only intended for

use in systems with a HUB, inverter, and 

FLEXmax.  If the system display connects only to

a FLEXmax, the only AGS function that will work

is the DC genset programming.  The other AGS

functions will not work properly. 

NOTE

:  The system display must have firmware

revision 4.1.6 or higher for AGS to work. 

aux control

o

 ON

o

 OFF   

 

MATE-Class Screens

 

MATE and MATE2 FLEXmax Menu Maps  

STATUS Menu Map

Navigation for

STATUS/CC/PAGE1 

o

 <

DOWN

> moves to 

the next menu item in 

the diagram.

o

 <

UP

> returns to the 

previous menu item in

the diagram. 

o

 <

PORT

> directs the

system display to read 

the next device (port) on

the HUB. 

o

 <

TOP

> returns to the

STATUS/CC/PAGE1 

screen.

o

 <

STATUS

> returns to 

the screen at the top of

the respective column. 

   

Navigation for

STATUS/CC/PAGE2 

o

 <

DOWN

> moves to the next

menu item in the diagram. 

o

 <

UP

> returns to the previous

menu item in the diagram. 

o

 <

PORT

> directs the system

display to read the next device 

(port) on the HUB.

o

 <

TOP

> returns to the 

STATUS/CC/PAGE2 screen. 

o

 <

STATUS

> returns to the

screen at the top of the 

 

respective column. 

MATE-Class Screens

 

MATE-Class Screens

 

Advanced Menu Map 

Navigation for

ADV/CC/PAGE1 

o

 <

DOWN

> moves to 

the next menu item in 

the diagram.

o

 <

UP

> returns to the 

previous menu item in

the diagram. 

o

 <

PORT

> directs the

system display to read 

the next device (port) 

on the HUB. 

o

 <

TOP

> returns to the

CC/PAGE1 screen. 

o

 <

ADV

> returns to the

choose device screen. 


Navigation for

ADV/CC/PAGE2 

o

 <

DOWN

> moves to 

the next menu item in 

the diagram.

o

 <

UP

> returns to the 

previous menu item in

the diagram. 

o

 <

PORT

> directs the

system display to read 

the next device (port) on

the HUB. 

o

 <

TOP

> returns to the

CC/PAGE2 screen. 

o

 <

ADV

> returns to the

choose device screen. 

MATE-Class Screens

IMPORTANT:   

Troubleshooting   

Be sure to check out the OutBack customer and user forum at

www.outbackpower.com/forum/ for more FLEXmax information. 

Symptom Remedy 

FLEXmax does not

boot/power-up

(blank LCD) 

FLEXmax not

producing expected

power 

FLEXmax not

equalizing 

 

 Check the battery connection and polarity.  Reverse polarity or an

improper connection will cause power-up issues. 

 Check the battery disconnect or circuit breaker.  Ensure all circuit

breakers are sized appropriately. 

 Check the battery voltage at the FLEXmax terminals.  A battery voltage

below 10.5 Vdc may not power up the FLEXmax.  A poor connection

may not allow sufficient voltage to reach the FLEXmax. 

 Check PV conditions.  Clouds, partial shading, or dirty panels can

cause poor performance. 

 Check settings.  The lower current limit set point in the Charger 

menu will yield a loss of power or poor performance symptoms.  

If the FLEXmax is in U-Pick mode, it may not track at the maximum

power point. 

 Check battery conditions and charging stage.  If the batteries are

charged (if the FLEXmax is in the Absorbing or Float stage), the

FLEXmax will produce only enough power to regulate the voltage at

the Absorbing or Float set point voltage.  Less power is required during

these stages. 

 Determine the specified short-circuit current of the PV array.  The MPP

current is related to this number.  Use a multimeter to determine if the

short-circuit current is in the expected range.  Array or wiring problems

may restrict the available power. 

 Check the PV array temperature.  At high temperatures, the maximum

power point voltage may be near or or lower than the battery voltage. 

 Make certain the equalization cycle has been started.   

~ In the EQ menu, press START to begin the process. When the

equalization cycle has been initiated, MPPT EQ will be displayed. 

 The equalization cycle has been initiated, but the battery is 

not equalizing. 

~ The cycle will begin when the target EQ set point voltage has been

reached.  A small array or cloudy weather will delay the EQ cycle. 

Running too many battery loads will also delay the cycle.  

~ Check the PV array temperature.  At high temperatures, the maximum

power point voltage may be near or lower than the battery voltage.  

This can delay the cycle. 

 

 

Troubleshooting

 

 

Symptom Remedy 

FLEXmax is always

SLEEPING   

 Check battery voltage.  If the battery voltage is at or above the

Absorbing voltage set point (compensated for battery temperature), the

FLEXmax will not wake up. 

 Check PV voltage.  The PV voltage has to be at least two volts greater

than the battery voltage for the initial wakeup. 

 If voltage is not present, check the PV array breaker (or fuse).  Confirm

the PV array breaker (or fuse) is sized appropriately. 

PV voltage reads 000

 If the PV array voltage on the display rises with the PV breaker OFF, 

Status screen shows

BatTmpErr  

 

FLEXmax internal fan

not running 

FLEXmax makes a

squealing sound 

LCD display 

scrambled 

but reads 000 with the PV circuit breaker on, the PV array polarity may

be reversed or shorted. 

 If the PV voltage still reads 000 with the PV circuit breaker off after a

minute, call OutBack Technical Support for assistance. 

 Confirm the type of temperature sensor.  Only the OutBack RTS

(remote temperature sensor) can be used with the FLEXmax. 

 If the RTS is correct, it may be faulty or damaged.  Disconnect the

RTS from the jack to resume normal operation.  Replace the RTS as

soon as possible. 

The internal fan will only run when the internal temperature has reached

approximately 112°F.  The fan will continue running until the internal

temperature is less than 104°F.  

If the MPP voltage is low enough to approach the battery voltage (usually

when the array is very hot), it is near the effective limit of the MPPT

function.  This may cause the FLEXmax components to make a squealing

noise.  The problem can be alleviated by placing the FLEXmax in

Extended Play, which extends the parameters of the MPPT sweep.  

See page 59 for instructions on using Extended Play. 

This mode may not be desirable under more standard conditions when the

PV voltage is higher.  The efficiency of the FLEXmax controller may be

reduced. 

Reboot the FLEXmax controller as described on page 60.  This will clear 

any operating problems or glitches.  It will also restore all programming

items to their factory default settings. 

 

Specifications   

Electrical and Mechanical Specifications  

Specification FLEXmax 60 FLEXmax 80 

Output Current Rating 

@ 40°C ambient 

60 amps continuous 80 amps continuous  

Nominal Battery System Voltage  12, 24, 36, 48 or 60 Vdc (adjustable) 

PV Open Circuit Voltage (V) 150 Vdc maximum (ETL Rating for UL1741 Standard);  

145 Vdc temperature corrected V (operational maximum) Standby Power Consumption  Less than 1 watt typical Charge Cycle Three-stage Voltage Regulation Set Points  13-80 Vdc Temperature Compensation  5 mV per °C per 2 V cell (with optional RTS)

PV Input Capability  Down convert from any acceptable array voltage to any battery voltage.  

Examples: 72 Vdc array to 24 Vdc battery; 60 Vdc array to 48 Vdc battery

Digital Display  4-line, 20-character per line backlit LCD display

Remote Interface  RJ45 modular connector Cat 5 cable 8 wire

Operating Temperature Range  –40° to 60°C (automatically derated above 40°C)

Conduit Knockouts  One 1” on the back; one 1” on the left side; two 1” on the bottom

Warranty Five years parts and labor

Dimensions 13.5” H × 5.75” W × 4” D 16.25” H × 5.75” W × 4”D

Shipping Dimensions 18” H × 11” W × 8” D 21” H × 10.5” W × 9.75”D

Weight 11.6 lb (14 lb boxed) 12.20 lb (15.75 lb boxed)

Options                                                 RTS, HUB 4, HUB 10, MATE, MATE2, MATE3, MATE3s

Menu Languages English and Spanish 

 

Firmware Revision  

This manual applies to FLEXmax 80 or FLEXmax 60 charge controllers with a firmware revision

of 003.003.000 or higher. 

Regulatory Specifications  


 

Table 3 Regulatory Specifications for All Models 

UL 1741 2nd Edition 

CSA C22.2 No. 107.1-01

IEC 62509:2010 

 

Specifications

 

Default Settings and Ranges  

Table 4 FLEXmax Settings

Mode Menu Item Setting 

Charger


Current Limit  (FM80)

Default 80 Adc  

Range: 5 to 80 Adc 

Current Limit  (FM60)

Default 60 Adc  

Range: 5 to 60 Adc 

Absorbing 

Default 14.4 Vdc 

Range:  Float setting

to 80 Vdc 

Float 

Default 13.8 Vdc 

Range: 12.0 Vdc to

Absorbing setting 

Vent Fan

Default <Off> 

Volts 

<On, Auto, Off> 

Default 14.4 Vdc 

Range: 10.0 to 80.0 

Vdc 

PV Trigger

Default <Off> 

<On, Auto, Off>

Hold Time Sec 

Default 01.1 second 

Range: 0 to 25 sec. 

PV VOLTS

Default 140 Vdc  

Range: 20 to150 Vdc 

ERROR OUTPUT

Default <Off> 

<On, Auto, Off>

ERROR  

LOW BAT VOLTS

Default 11.5 Vdc  

Range: 10 to 80 Vdc 

Night Light

Default <Off> 

<On, Auto, Off>

ON Hysteresis Time 

(Minutes)

Default 001 minute 

Range: 001 to 255 min.

On Time (Hours) 

Default 04 hours 

Range: 00 to 23 hours 

Threshold Voltage

Default 010 Vdc  

Range: 005 to 150 Vdc 

Float

Default <Off> 

Diversion:Relay 

<On, Auto, Off> 

Default <Off> 

<On, Auto, Off>

Hold Time 

(Seconds)

Default 0.1 second 

Range: 0.0 to 25 sec. 

Delay  Time

(Seconds) 

Absorb-Float-EQ

Relative Volts 

Default 0.0 seconds

Range: 0.0 to 24 sec. 

Default 0.0 Vdc 

Range: 0.0 to 5.0 Vdc 

HYST

Default 00.2 Vdc  

Range: 0.0 to12.0 Vdc 

Diversion:Solid St

Default <Off> 

<On, Auto, Off>

Hold Time 

(Seconds)

Default 0.1 second  

Range: 0.0 to 25 sec.

Delay  Time 

(Seconds)

Default 00 seconds

Range: 00 to 24 sec. 

Absorb-Float-EQ

Relative Volts 

Default 0.0 Vdc

Range: 0.0 to 5.0 Vdc 

HYST

Default 00.2 Vdc  

Range: 0.0 to12.0 Vdc 

Mode Menu Item Setting 





Aux

(cont’d)

 

Light 

EQ 

Advanced 

Low Battery Disconnect

Default <Off> 

<On, Auto, Off>

Delay Time Sec 

DISCONNECT

VOLTS 

RECONNECT

VOLTS 

Default 01 second 

Range: 000 to 250 sec. 

Default 13.6 Vdc

Range: 10 to 80 sec. 

Default14.4 Vdc

Range: 10 to 80 sec. 

Remote

Default <Off> 

<On, Auto, Off> 

MODE

Default <AUTO> 

<ON, AUTO, OFF>

Auto Time 

BATTERY EQUALIZE

Volts 

BATTERY EQUALIZE

Time  

Default 2 minutes 

Range: 1 to 9 minutes 

Default 14.4 Vdc 

Range: Absorbing

setting to 80 Vdc 

Default 01 hours  

Range: 1 to 7 hours 

EQ INTERVAL

Default 000 days  

Range: 000 to 250 days 

Snooze Mode

Default 0.6 Adc   

Range: 0.2 to 1.0 Adc

Wakeup Mode Volts  

Default 1.5 Vdc  

Range: 1.5 to 9.5 Vdc 

Wakeup Mode Time 

Default 05 minutes 

Range:  05 to 15 min. 

MPPT Mode

Default <AutoTrack > 

<Auto Track or 

U-Pick> 


 Range: 40 to 90% V

Park Mpp

Default 77% V


MPP Range Limit 

(Max)

Default <90%> 

<80, 85, 90, 99%> 

MPP Range Limit

(Min) 

Default <1/2> 

<1/2 or FULL> 

Absorb Time Limits

Default 01.0 hours 

Range: 00.0 to 24 hrs.

Absorb End Amps 

oc

Default 00 Adc 

Range: 00 to 55 Adc 

Rebulk Voltage

Default 12.0 Vdc

Range: 12.0 Vdc to

Float setting 

Vbatt Calibration

Default 0.0 Vdc   

Range:  -0.5 to 0.5 Vdc

RTS Compensation 

Upper Limit

Default 14.1 Vdc   

RTS Compensation 

Auto ReStart

 

Aux Polarity 

 

Lower Limit 

Range: Lower Limit

setting to 80 Vdc 

Default 14.1 Vdc   

Range: 10 Vdc to

Upper Limit setting 

Default <0>

Selections <0, 1 , 2> 

Default <Active High>

<Active High or Low> 

Applications   

Maximum Power Point Tracking     

Maximum Power Point Tracking (MPPT) is the technology used by FLEXmax controllers to

optimize the harvest of power from PV arrays.   

PV modules do not have a defined operating voltage.  Their voltage is defined strictly by the

load connected to them.  With no load (disconnected), a module displays “open-circuit” voltage

(V), and delivers no current.  At full load (shorted), a module has no voltage, although it

delivers the maximum “short-circuit” current (I).  In neither case does the module produce

usable wattage. 

When partially loaded, a PV module delivers partial current and voltage.  These numbers can be

multiplied to see the available wattage.  However, the delivery of wattage is not linear.  The

current and voltage delivered at a given load will change with the load, along a curve such as

that shown in the drawing to the left in Figure 99.  This is known as the V-I curve.  The wattage

is different at every point along the curve.  (The V-I curve also varies with module type and

manufacturer.)  Only one point on the curve represents the delivery of the module’s maximum

(rated) wattage.  This is  known as the maximum power point , or MPP.  The current at this

point, I is the highest that can be drawn while still maintaining the highest voltage, V

The FLEXmax controller places a variable load on the PV array and tracks the result to 

determine the maximum power point.  This process, MPPT, is maintained so that the FLEXmax

can deliver the maximum PV power regardless of any change in conditions.  The drawing to the

right in Figure 99 shows the MPP and compares the V-I curve against the available wattage. 

MP

C U RR EN T 

C U RR EN T 

VOLTAGE

VOLTAGE 


 

 

 V

  V-I curve Available wattage 

Applications

 

Three-Stage Battery Charging  

The FLEXmax charge controller is a sophisticated, multi-stage battery charger that uses several 

regulation stages to allow fast recharging of the battery system while ensuring a long battery

life.  This process can be used with both sealed and non-sealed batteries.  The FLEXmax is a

“buck” converter which turns higher PV voltages into the lower charging voltages used by

batteries (with correspondingly higher currents).  The chart in Figure 100 shows the voltage

levels achieved by the PV array throughout a typical day, and the battery voltages (by stage)

during the same times. 

The FLEXmax has preset recharging voltage set points (Absorbing and Float voltages);

however, OutBack always recommends using the battery manufacturer’s recommended

charging voltages.   

A new charge cycle is started any time the battery voltage decreases below the Rebulk set 

point.  (See page 53.)  This usually occurs each night unless the batteries were maintained by

another means.  (If so, they may not need to be recharged).  See pages 22 through 26 for the

messages displayed onscreen during the various stages. 

BULK  

This is the first stage in the three-stage charge cycle.  It is a constant-current stage which drives

the battery voltage up.  The DC current is the maximum current the charger can deliver.  This

stage typically leaves the batteries at 75% to 90% of their capacity, depending on conditions.   

In the Bulk stage, the FLEXmax will charge the batteries to the Absorbing voltage setting (see 

page 29).  This stage is not timed.  It will charge as long as necessary to complete the stage,

regardless of any timer set points.  If little PV energy is available, it may take a long time for this

stage to complete.  If the FLEXmax is in a different stage and little PV energy is available, it may

return to Bulk.  (See page 22.)  This stage is temperature-compensated.  (See page 99.) 

 

Time  

ABSORBING  

Applications

This is the second stage of charging.  It is a constant-voltage stage.  Current varies as needed

to maintain the Absorbing voltage setting.  However, it will typically decrease to a very low

number over time.  This “tops off the tank”, leaving the batteries at essentially 100% of capacity. 

The duration of the Absorbing stage is the user-defined Absorb Time Limit.  The ChgT timer is

preset to zero following the previous charge cycle.  Once in Absorbing, ChgT will count until it

reaches this limit.  (See pages 22, 47, and 51.)  The charger will then exit Absorbing and enter

the Float stage.  The charger will also also exit Absorbing if the Absorb End Amps setting is

reached, regardless of the timer.  This resets the timer to zero.  (See page 47.)  This stage is

temperature compensated.  (See page 99.) 

FLOAT  

When the charger enters this stage, it reduces the voltage to prevent battery overcharging.  The

batteries are maintained at the Float set point.  Floating is displayed on the screen.  This stage

is not timed.  The FLEXmax will continue to maintain Float as long as PV energy is available. 

If the PV cannot supply enough power to maintain the Float set point, the FLEXmax will not

immediately initiate a new charge cycle.  It will attempt to draw more PV energy and recharge

the battery until the Float voltage set point is reached.  When this occurs, MPPT Float is

displayed (see page 25).  This stage is temperature compensated.  (See page 99.) 

A new cycle can be initiated if the voltage falls below the ReBulk set point (see page 53). 

Battery Temperature Compensation  

 

Battery performance changes when the temperature varies above or below room temperature

(77°F or 25°C).  Compensation is a process that adjusts charging to correct for these changes. 

When a battery is cooler than room temperature, its internal resistance goes up and the voltage

changes more quickly.  This makes it easier for the charger to reach its voltage set points. 

However, while accomplishing this process, it will not deliver all the current that the battery

requires.  As a result, the battery will tend to be undercharged.   

Conversely, when a battery is warmer than room temperature, its internal resistance goes down

and the voltage changes more slowly.  This makes it harder for the charger to reach its voltage

set points.  It will deliver energy as time passes until the set points are reached.  However, this

tends to be more than the battery requires, meaning it will tend to be overcharged. 

The FLEXmax controller, when equipped with the Remote Temperature Sensor (RTS) will

compensate for temperature.  The RTS is attached to a single battery near the center of the

bank.  When charging, the RTS will increase or decrease the charge voltage by 5 mV per

degree Celsius per battery cell.  This setting affects the Absorbing and Float set points. 

Equalization is not compensated in the FLEXmax. 

 In a 12 Vdc system (6 cells, 2 volts each), this means 0.03 volts per degree Celsius above or below 25°C. 

Maximum compensation is ± 0.6 Vdc. 

 In a 24 Vdc system (12 cells, 2 volts each), this means 0.06 volts per degree Celsius above or below 25°C. 

Maximum compensation is ± 1.2 Vdc. 

 In a 48 Vdc system (24 cells, 2 volts each), this means 0.12 volts per degree Celsius above or below 25°C.  

Maximum compensation is ± 2.4 Vdc. 

Examples: 

 A 12 Vdc system with 10°C batteries will compensate its charging to 0.45 Vdc higher than the set points.  

 A 24 Vdc system with 35°C batteries will compensate its charging to 0.6 Vdc lower than the set points.

 A 48 Vdc system with 15°C batteries will compensate its charging to 1.2 Vdc higher than the set points. 

Applications 

Array Design 

Sizing Guidelines 

Below is a list of maximum array wattages for the FLEXmax for various nominal voltage

batteries.  This should be used for sizing an array.  Note that every PV module is different.  The

specifications for every model should be consulted before designing or assembling a PV array. 

Table 5 Maximum PV Input Wattage per Charge Controller  

Nominal

Battery

Voltage 

Maximum Array Size

(in watts, Standard Test Conditions) 

FLEXmax 80 FLEXmax 60

 

12 V 1000 W 800 W 

24 V 2000 W 1600 W 

36 V 3000 W 2400 W

48 V 4000 W 3200 W

60 V 5000 W 4000 W 

Open Circuit Voltage (V

Open-circuit voltage (V) is the unloaded voltage generated by the PV array.  The FLEXmax

controller can withstand V of up to150 Vdc.  However, if the V exceeds 145 Vdc, the

FLEXmax will suspend operation to protect the system components. 

CAUTION:  Equipment Damage 

Although the FLEXmax shuts down when voltage is greater than 145 Vdc, this will not

prevent the array from generating voltage.  Anything higher than 150 Vdc will damage the

FLEXmax, whether it has shut down or not.  The array should be designed so that voltage

never exceeds 145 Vdc in order to prevent equipment damage. 

Weather Conditions  

Cooler climates can cause the V to rise above the array’s rated V temperatures less than about –15°C (5°F), a V

Hot weather: lower V

Cold weather: higher V

 and lower V

 and higher V

1.  In climates that observe 

 greater than 125 Vdc is not recommended. 

If the specific voltage temperature correction factor is not known for a particular module, allow for ambient

temperature correction using the following information: 

25° to 10°C (77° to 50°F)  multiply V by 1.06

9° to 0°C (49° to 32°F)  multiply V by 1.10 

–1° to –10°C (31° to 14°F)

multiply V by 1.13 

–11° to –20°C (13° to –4°F)

multiply V by 1.17 

–21° to –40°C (–5° to –40°F)

multiply V by 1.25 

 Based on the most common solar arrays under Standard Test Conditions (1000 watts per square meter

to solar panel at 25°C [77°F] ). 

Maximum-Power Voltage (V

Maximum-power voltage (V) is the operating voltage for the PV array at which the array

generates the most wattage.  When designing the PV array, it is recommended for the V

Applications

to be

approximately 12 to 24 volts higher than the nominal battery voltage for optimum performance. 

This will ensure that the V

mp

 is always above the battery voltage, which is required for charging. 

Higher voltages are not recommended, as they may reduce the FLEXmax conversion efficiency.  

IMPORTANT:   

Check the PV array voltage before connecting it to the FLEXmax. 

Standard vs. Australian Default Settings     

Several version settings are available for the FLEXmax upon initial setup.  These can be 

selected upon initial power-up.  (See page 17.)  The English and Spanish versions have the

same standard default settings; however, the Australian version has certain default settings that

are different.  However, there are no differences in performance and efficiency between the two

versions.  The standard and Australian version can be identified as follows: 

 

Standard Power Up Screen 

OutBack            12V

        Power

               Systems

Charge Controller 

Australian Power Up 

OutBack            12V

        Power

               Systems

Charge Controller - AU 

Figure 101 Standard vs. Australian Power-up Screens 

Table 6 Default Settings Standard vs. Australian 

Settings Standard Australian 

Charger Absorbing Float Absorbing Float

12 V 14.4 V 13.6 V 14.4 V 13.8 V 

24 V 28.8 V 27.2 V 28.8 V 27.6 V 

36 V 43.2 V 40.8 V 43.2 V 41.4 V

48 V 57.6 V 54.4 V 57.6 V 55.2 V

60 V 72.0 V 68.0 V 72.0 V 69.0 V

Equalize Volts  Equalize Volts 

12 V 14.4 V  14.7 V 

24 V 28.8 V  29.4 V 

36 V 43.2 V  44.1 V 

48 V 57.6 V  58.8 V 

60 V 72.0 V  73.5 V 

Equalize Time 01 Hours  03 Hours  

 

Applications

 

Hydroelectric and Fuel Cell Applications

Performance Optimization     

The FLEXmax Charge Controller is designed to work with PV arrays.  Although it will work with

hydroelectric turbines and fuel cells, OutBack Power Technologies can only offer limited

technical support for these applications due to variance in turbine and fuel cell specifications.  

 


IMPORTANT:   

The FLEXmax Charge Controller is not usable for direct regulation of wind turbine input and

OutBack cannot warranty its use in these applications.  In wind turbine applications, the

FLEXmax is recommended as a diversion controller.  (See page 38.) 

The FLEXmax maximum power point tracking (MPPT) function can be set to Auto Track or

U-Pick% mode as described on page 51.  The MPPT function is based on the open-circuit

voltage (V) of the DC source.  This is the unloaded voltage displayed by the source when it is

disconnected.  MPPT values are expressed as a percentage of V

.  Auto Track mode allows

the FLEXmax to sweep the range of percentages.  The Auto Track mode begins at the

maximum value and loads the array, working its way through lower voltages, until it locates the

input voltage that yields maximum wattage. 

Auto Track Mode 

The default minimum value of Auto Track is 1/2 (50% of V).  The default maximum is 90% of V

. This is the standard maximum-power range for PV.  A hydroelectric or fuel-cell system’s

operating voltage may operate in a different range and often have a maximum-power voltage

close to the battery voltage.  The FLEXmax allows a user to set a sweep range more

appropriate for the source.  The minimum setting can be changed to FULL, which is 40% of the

V.  The maximum value can be set from 80% to 99% of V if necessary.

This adjustment only affects the initial tracking at the beginning of the day and any subsequent 

trackings caused by Auto-Restart or any forced restart of the FLEXmax. 

U-Pick Mode 

If an optimal voltage is known for a given DC source, then this voltage can be set as a 

designated V percentage in U-Pick% mode.  This percentage is assigned in the Park Mpp set

point, which allows a range of 40% to 99% of V  If U-Pick % Voc is chosen, the FLEXmax will

load the source to operate continuously at the designated voltage.  It will not sweep for the

maximum power point and will ignore all Auto Track value

Main Menu 

Charger  Aux   Light

  EQ    Misc  Advanced

  Logging    Stats 

EXIT          GO 

ADV SETUP Screen 

 Charger Aux   Light

  EQ   Misc Advanced 

  Logging    Stats

EXIT          GO 

     ADVANCED MENU

      Snooze Mode

       < 0.6 amp

EXIT  NEXT        AMP 

Mpp Range Limit % Voc 

     ADVANCED MENU

Mpp Range Limit %VOC

             Min   Max

EXIT  NEXT   1/2   90% 

MPPT Mode (Auto Track) 

     ADVANCED MENU

       MPPT Mode

      Auto Track

EXIT  NEXT  nonGT MODE 

U-pick% (Voc) MPPT Mode 

     ADVANCED MENU

       Park Mpp

Watts 0251    77 % Voc

EXIT  NEXT   -%    +% 

To adjust the Lower Mpp Range Limit:    

 

Figure 102  Adjusting Range Limits for Hydroelectric

or Fuel-cell Applications   

900-0009-01-00 Rev D 103 

Applications

 

1. From the main menu, press <> to move the arrow

next to the Advanced function. 


 

2. Press <GO>. 

 




 

3. In the ADVANCED MENU screen, press <NEXT>

again to display the Mpp Range Limit % Voc screen.  




 

4. Press <1/2> until FULL appears. 

 

5. When finished, press <NEXT> until the MPPT Mode

screen appears. 

 

To pick between Auto Track or U-Pick % MPPT Mode and determine

the charge controller’s operating V

 percentage, press <MODE> to 

interchange between the two modes.  

 

Re-entering the password might be required.  After choosing a mode,

press <NEXT> in the ADVANCED MENU to view the Park Mpp screen 

(only applicable for U-Pick mode).


 

Press < –%>  or <+%> to select one of the percentage values; U-Pick

always uses the Park Mpp value.  

 

 

Applications

 

Grid-Interactive Settings     

When using an OutBack inverter, FLEXmax, HUB, and system display, set the FLEXmax to 

GT in the Advanced menu.  GT mode allows the inverter to manage the FLEXmax Float setting. 

It ensures the FLEXmax always keeps the battery above the sell voltage of the inverter.  

(See page 51.) 

When using a FLEXmax charge controller with an inverter without the use of a HUB, GT mode

will not work because the FLEXmax cannot communicate with the inverter.  In this situation,

when selling electricity back to the grid, keep the inverter’s “sell” voltage setting below the

FLEXmax Float setting.   In a 24-volt battery system, the difference should be at least 0.5 Vdc. 

In a 48-volt system, the difference should be at least 1.0 Vdc. 

 

FLEXmax Efficiency vs. Input Power  

 

Definitions 

The following is a list of initials, terms, and definitions used with this product. 

Table 7 Terms and Definitions  

Term Definition 

AC Alternating Current; refers to voltage produced by the inverter, utility grid, or

generator 

 

 

AGS   Advanced Generator Start 

AUX Inverter’s 12-volt auxiliary output

DC Direct Current; refers to voltage produced by the batteries or renewable source

DVM Digital Voltmeter   

FN-DC FLEXnet DC; the OutBack Battery Monitor

Grid-interactive,  

grid-tie  

Utility grid power is available for use and the system is capable of returning

(selling) electricity back to the utility grid. 

Ground Fault An unsafe condition of current flow to ground, resulting from accidental contact

between an electrical source and ground 

I

mp

Maximum-power current; the current harvested by MPPT when operating at the

V

mp

 

I

sc

Short-circuit current; the fully-loaded current displayed by a PV module or array

LED Light-Emitting Diode; refers to indicators used by the inverter and the system 

display

MPP, MPPT   Maximum Power Point, Maximum Power Point Tracking 

Negative-Ground A wiring system that bonds the negative conductor to ground for safety 

Positive-Ground A wiring system that bonds the positive conductor to ground for safety

PWM Pulse-Width Modulation 

PV Photovoltaic

RTS Remote Temperature Sensor; accessory that measures battery temperature for 

 

Applications

 

charging

SK Soft Key; a key with programming that varies with screen    

System display   Remote interface device (such as the MATE, MATE2, MATE3, or MATE3s), used 

for monitoring, programming and communicating with the inverter; also called

“remote system display”         

V

mp


Maximum-power voltage; voltage sought by MPPT where maximum power is 

harvested

V


Open-circuit voltage; the unloaded voltage displayed by a PV module or array 


 

Applications


Absorb End Amps .................................................... 52

Absorb Time Limits .................................................. 52

Absorbing ........................................................... 22, 99

Advanced Menu ....................................................... 49 

Absorb End Amps ............................................... 52

Absorb Time Limits .............................................. 52

Auto ReStart ........................................................ 55

AUX Polarity ........................................................ 56

Logging ............................................................... 57

MPPT Mode ........................................................ 50

Rebulk Voltage .................................................... 53

Reset to Defaults ................................................. 56

RTS Compensation ............................................. 53

Snooze ................................................................ 49

Stats .................................................................... 58

Vbatt Calibration .................................................. 53

Wakeup Mode ..................................................... 50 

AGS ............................ See Automatic Generator Start

Applications .............................................................. 97

Array Design .......................................................... 100

Australian Settings ................................................. 101

Auto ReStart ................................................ 23, 55, 69

Auto Track ................................................................ 50

Automatic Generator Start (AGS) ..................... 44, 105

AUX ........................................................................ 105

AUX Modes ........................................................ 30, 68 

Diversion ............................................................. 38

Error Output ......................................................... 35

Float .................................................................... 37

Low Battery Disconnect ....................................... 43

Night Light ........................................................... 36

PV Trigger ........................................................... 34

Remote ................................................................ 44

Vent Fan .............................................................. 33 

AUX Polarity ............................................................. 56

AUX Terminals ......................................................... 13 

Backlight .................................................................. 44

Battery Charging .............................. 29, 66, 76, 80, 98

Battery Voltage ................................................... 17, 18

Bulk .................................................................... 24, 98 

Calibration .......................................................... 53, 70

Charger Setup .............................................. 29, 66, 80

Contact Information .................................................... 2 

D  

Index 

Data Logging .................................... 21, 57, 63, 71, 77

Default Settings ................................................ 96, 101

Defaults .................................................. 17, 56, 60, 70

Definitions .............................................................. 105

Diagrams ................................................ 14, 15, 16, 42

Dimensions .............................................................. 10

Diversion 

Relay ................................................................... 38

Solid St ................................................................ 40 

Efficiency ................................................................ 104

End-of-Day Summary Screen .................................. 20

Equalizing .............................................. 23, 25, 45, 67

Extended Play .................................................... 59, 94 

Features ................................................................. 7, 8

Firmware Revision ......................................... 7, 59, 95

FLEXware ................................................................ 11

Float ............................................................. 24, 25, 99

Fuel Cell Applications ..................................... 102, 103 

Graph Screens ......................................................... 64

Grid-Tie .................................. 24, 47, 51, 67, 104, 105

Grounding ............................................................ 9, 13 

GT Mode ........................................ 24, 47, 51, 67, 104 

Hydroelectric Applications .............................. 102, 103 

Initial Operation ........................................................ 27

Installation .................................................................. 9

Introduction ................................................................ 7 

Language ........................................................... 17, 18

Logging .................................................. 21, 57, 71, 77 

Index

Main Menu ......................................................... 17, 27

MATE and MATE2 

Advanced Menus ................................................. 79

AUX ................................................................ 83

CC ADV .......................................................... 81

CHRG ............................................................. 80

EQ .................................................................. 82

Menu Map ....................................................... 86 

CC ADV Menu Map ....................................... 86, 87

CC STATUS Menu Map ................................ 84, 85

Password ............................................................ 79

Status Screens .................................................... 74 

CC LOG .......................................................... 77

CC SETPT ...................................................... 76

CC STAT ........................................................ 78

Menu Map ....................................................... 84

Meter .............................................................. 75 

Mode .............................................................. 74 

Summary Screens ............................................... 73

MATE3 and MATE3s 

Auxiliary Output ................................................... 68

Calibrate .............................................................. 70

Charger Settings ................................................. 66

Device Data Logs ................................................ 71

Equalization ......................................................... 67

Grid-Tie Mode ..................................................... 67

Menu Structure .................................................... 65

MPPT .................................................................. 66

Password ............................................................ 65

Restart Mode ....................................................... 69

Screens ............................................................... 61

Temperature Compensation ................................ 67 

Maximum Power Point Tracking ......................... 50, 97

Maximum PV Wattage ........................................... 100

Maximum-Power Voltage ................................. 97, 101

Menu Maps .............................................................. 28 

FLEXmax........................................... 89, 90, 91, 92

MATE and MATE2 ............................ 84, 85, 86, 87

MATE3 and MATE3s ........................................... 65 

Misc Screen ............................................................. 47

Modes ...................................................................... 22 

Absorbing ............................................................ 22

AutoRestart ............................................. 23, 55, 69

AutoStart ....................................................... 23, 69

BatTmpErr ..................................................... 23, 94

BatTooHot ........................................................... 23

Charged .............................................................. 23

EQ ....................................................................... 23

EQ Done ............................................................. 23

EX Absorb ........................................................... 24

Floating ............................................................... 24

GT Mode ....................................................... 24, 67

High Voc .............................................................. 24

Low Light ............................................................. 24 

MPPT Bulk .......................................................... 24 

MPPT EQ ............................................................ 25

MPPT Float ......................................................... 25

New Voc .............................................................. 25

Over Temp .......................................................... 25

OvrCurrent........................................................... 25 

Re-Cal ................................................................. 25 

Sleeping ........................................................ 25, 94

Snoozing ............................................................. 24

Sys Error ............................................................. 26

Tracking .............................................................. 26

Unloaded ............................................................. 26

Wakeup ............................................................... 26

Zzzzz ................................................................... 26 

Modes ...................................................................... 62

Mounting .................................................................. 11

MPPT ......................................................... 50, 97, 105 

Open-Circuit Voltage ........................................ 97, 100

Operation ................................................................. 17 

Password ..................................................... 17, 65, 79

Photovoltaic ........................................................... 105

Ports ......................................................................... 13

Powering Up ............................................................ 17

PV Design .............................................................. 100 

Rapid Shutdown ......................................................... 9

Rebooting the FLEXmax .......................................... 60

Rebulk Voltage ......................................................... 53

Remote Temperature Sensor ............... 13, 53, 67, 105

Reset to Defaults .................................... 17, 56, 60, 70

RTS ........................ See Remote Temperature Sensor 

Settings .................................................................... 27

SK ......................................................... See Soft Keys

Snooze Mode ........................................................... 49

Soft Keys ............................................................ 8, 105

Specifications ........................................................... 95

Standard vs. Australian Default Settings ................ 101 

STATS Menu...................................................... 58, 78 

Status Screen..................................................... 19, 22

System Display ...................................................... 105 

MATE and MATE2 .............................................. 73

MATE3 and MATE3s ........................................... 61 

Temperature ............................ 25, 48, 53, 67, 99, 100

Terminals ................................................................. 13

Three-Stage Battery Charging ................................. 98

Timers 

Float (reading) ..................................................... 63 

Troubleshooting ....................................................... 93 

U-Pick ...................................................................... 50 

Vbatt Calibration ................................................. 53, 70

Index

 

Wakeup Mode .......................................................... 50

Weather Conditions ................................................ 100

Wiring ..................................... 9, 12, 13, 14, 15, 16, 42 

 

 

 

  

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