The OutBack FLEXmax is one of the most versatile chargers that we have tested. It has a very intuitive user interface that makes programming it to work with a Battle Born Battery very straightforward.

Tools Needed:

1. #2 Phillips Screwdriver

2. Flat Head Screwdriver

Before starting, make sure to disconnect PV systems that may be powering the FLEXmax.

For clarity,  reference the buttons according to their number in the picture below.

Outback FLEXmax buttons

Step 1:

Unscrew the front panel on the unit using the #2 Phillips screwdriver.

Step 2:

Connect your Battle Born Batteries positive and negative terminals to the FLEXmax’s positive and negative terminals, respectively.

The unit will power on.

Step 3:

Follow through the manual that was provided with the FLEXmax to get to the “Status Screen.”

This is the screen that is in the picture above that displays the voltages coming in and out of the unit.

From this screen, press the 1st button. You will now be on the “Main Menu Screen.”

Step 4:

Press the 4th button labeled “GO” on the screen to select “Charger.” On the “Charger” menu, change each parameter to the following:

  • Current Limit: This will depend on what amplitude you want to charge your battery bank at.
  • Absorbing: 14.4 V
  • Float: 13.4 V

Press the 1st button to exit this screen. Press the 1st button again to return to the “Main Menu Screen.”

Step 5:

Press the 3rd button until  the cursor is to the left of “EQ.”

Press the 4th button to enter the “EQ” menu.

Set the EQ voltage to 14.4 V.

Press the 2nd button to move to the next screen.

Set the battery equalization time to as low as possible.

Then press the 1st button to exit.

By default, Equalization is set to be manually turned on. Be sure to never turn equalization on, as it is not necessary with Battle Born Batteries.

Step 6:

If you are using a remote temperature sensor, disconnect it from both the battery and the FLEXmax. Battle Born Batteries do not need temperature compensation.

Your FLEXmax is now configured to be used with Battle Born Batteries!

Share this