Battery System Float Charging - Alpha alphacell gelcell series User Manual

4.0 Battery System Float Charging

Battery System Float Charging Voltage
NOTE:
The following set points are recommended for AlphaCell Batteries when used with the xM
Series 2 or GMx Power Supply.
20
Encountering temperature extremes
When you encounter temperature extremes, temperature compensate the float
charging voltage. The temperature compensation coefficient is -0.0028 V/C per °F
(-0.005 V/C per °C).
For example if the normal battery temperature is 90°F (13° above 77°F) you should
reduce the average float charging voltage range by 0.036 V/C (13° x -0.0028 V/C per
°F) to between 2.21 and 2.26 V/C. For an 18 cell battery this is 39.78 to 40.86 VDC.
This helps reduce the potential for thermal runaway at elevated temperatures.
If the battery operates at cold temperatures, (60°F, 17° below 77°F, for example), you
can increase the charging voltage to improve recharging time.
For example, increase the charging voltage range by -17° x -0.0028 V/C per degree
or 0.048 V/C. For the 180 cell string this is 41.36 to 42.26 Vdc.
Under or overcharging
If the battery is undercharged for a period of time during which there are multiple
discharges, the battery does not fully recharge after each discharge and provides
progressively lower capacity.
Excessive overcharging causes premature aging of the battery and loss of capacity,
noted by excessive float current, corrosion of the plate grids, and gassing and drying
of the limited amount of electrolyte.
Severe overcharging over extended periods of time can induce a thermal runaway
condition. This requires replacing the battery system.
AlphaCell GelCell Batteries
TM
Bulk / Float
Accept
Temp Comp
AlphaCell 195GxL FT
TM
Bulk / Float
Accept
Temp Comp
AlphaCell IGL Series
TM
Bulk / Float
Accept
Temp Comp
2.27 V/C
2.40 V/C
-5mV/C/C
2.26 V/C
2.35 V/C
-4mV/C/C
2.25 V/C
2.32 V/C
-3mV/C/C
745-680-C0-002, Rev.B1