Outback Power Systems 80 Battery Temperature Compensated Volatge Set Point, Expected Temperature

33. BATTERY TEMPERATURE COMPENSATED VOLATGE SET POINT

The temperature of a battery has an impact on the recharging process—in higher ambient tempera- tures, the regulation set points (Absorb and Float) need to be reduced to prevent overcharging of the batteries. In lower ambient temperature conditions, the voltage regulation set points need to be increased to ensure complete recharging of the batteries.

The default charger settings of the FLEXmax 80 are based on typical lead acid battery systems. Always ensure the Absorb and Float voltage regulation set points are set to the recommended battery manufactur- er’s recharging regulation voltages.

Non-Battery Temperature Compensated System

If a battery remote temperature sensor is not available the Absorb and Float voltage regulation set points can be adjusted for the expected weather conditions. The following table shows the appropri- ate adjustments for both Absorb and Float voltage regulation set points for weather conditions above or below 77˚F / 25 C

EXPECTED TEMPERATURE	ADJUST SET POINT	12V	24V	48V
Average = 95˚F / 35˚C	Subtract	0.30V	0.60V	1.20V
Average = 86˚F / 30˚C	Subtract	0.15V	0.30V	0.60V

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Average = 68 F / 20˚C	Add	0.15V	0.3 V	0.60V
Average = 59˚F / 15˚C	Add	0.30V	0.60V	1.20V

Battery Temperature Compensated System

A battery remote temperature sensor (RTS) will automatically compensate the Absorb and Float voltage relative to the Absorb and Float set points in the Charger menu. Please reference page 49 of this manual for adjusting the upper and lower battery compensated limits.

Battery temperature compensation with other slopes

The FLEXmax 80 uses a 5mV per degree C per cell (2V) compensation slope required by UL. For other slopes, you may be able to pick a different battery voltage and change the charger Absorb and Float voltage settings to achieve a more or less aggressive slope. If going lower in voltage, reduce the Float voltage first, since the Absorb voltage will not be adjustable below the Float voltage setting. If going higher in voltage, increase the Absorb setting first before raising theFloat voltage above the present setting. Here is a table of FLEXmax 80 compensation based on system voltage for reference:

12V system	-30mV/degree C
24V system	-60mV/degree C
36V system	-90mV/degree C
48V system	-120mV/degree C
60V system	-150mV/degree C

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