Standby Power Battery Sizing: CP calculation

Constant Power Discharge Calculation Example
Constant Power Discharge Tables

DUTY: 400 KVA for 15 minutes
Power Factor: 0.80
Efficiency: 0.90
Maximum Voltage: 435 volts
Minimum Voltage: 306 volts
Temperature: 25° Centigrade
Power Requirement: KVA x Power Factor / Efficiency
400 x 0.80 / 0.90 = 355.6 kW
Maximum number of cells: Maximum Voltage / 2.25 volts (nominal cell float voltage)
435 / 2.25 = 193 cells
Minimum Cell Voltage: Minimum Battery Voltage / Number of Cells
306 / 193 = 1.58 volts
Watts per Cell Required: Power Requirement (Watts) / Number of Cells
355.6 x 1000 / 193 = 1843 Watts

From the data sheets for Constant Power discharges to 1.60 volts for 15 minutes

YHP19 gives 1973 watts for 15 minutes to 1.60 volts
FHP21 gives 1925 watts for 15 minutes to 1.60 volts
11RCT1100 gives 1901 watts for 15 minutes to 1.60 volts
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