Outback Power Systems FLEXmax Extreme Owners Manual - Manual (Page 23)

Installation
900-0150-01-00 Rev A 21
Power Up
IMPORTANT:
 The charge controller automatically senses the nominal battery voltage upon
connection. Once set, it retains the nominal voltage setting. Following any type of
shutdown or disconnect, it will return to operation automatically.
 The PV array voltage is automatically detected upon connection. The PV array
voltage must never exceed 150 V
oc
.
 It is recommended to restore the FLEXmax Extreme to factory default settings
(see page 45) and reset the nominal voltage (see below) any time the system is
substantially revised or the controller is relocated.
The FLEXmax Extreme uses power from the battery bank to operate. The battery voltage must be at least
10.5 volts or higher to power up the charge controller. When battery power is detected, the charge controller
will flash each of its LED indicators twice in a self-test.
The Status indicator (see page 23) will then flash to show the nominal system voltage that was detected. Each
flash indicates an increment of 12 volts; therefore, one flash = 12 Vdc, two flashes = 24 Vdc, and so on.
Figure 18 LED Indicators
Setting the Nominal Voltage
Upon initial power-up, the FLEXmax Extreme will sense the battery voltage and use this reading to determine
the nominal system voltage — a battery bank of 12, 24, 36, 48, or 60 volts DC.
The ranges of detection for each nominal battery voltage are:
 12-volt system — 10.5 Vdc to 15.7 Vdc
 24-volt system — above 15.7 Vdc to 31.4 Vdc
 36-volt system — above 31.4 Vdc to 43.2 Vdc
 48-volt system — above 43.2 Vdc to 62.8 Vdc
 60-volt system — above 62.8 Vdc to 78 Vdc
The batteries must be within the appropriate voltage range for the controller to take the correct reading. A
severely discharged 24-volt battery bank, for example, could read as a 12-volt bank and cause the controller to
Charging Indicator — Blue LED
Status Indicator — Green/Red (or Amber) LED
AUX Indicator — Yellow LED
Fault Indicator — Red LED