Stationary Battery Sizing

The IEEE 485 period method for switchgear, UPS and control batteries: the duty cycle in sections, capacity rating factors from the manufacturer or an estimate, and the temperature, aging and margin corrections.

Screening

Duty cycle periods in order, from the start of the discharge

Period	Duration (min)	Load (A)

System and battery

ChemistryNominal DC voltageMinimum system voltageCellsTemperature factorAging factorDesign margin

Capacity rating factor K

Enter the manufacturer's K (hours) by durationPeukert exponent (estimate)

Example: a 125 V switchgear battery. Without a manufacturer K curve the tool estimates K from the 8-hour rate.

Result

Enter the discharge periods in order and the DC system voltages.

RokBench is a screening tool intended to assist qualified engineers. It does not constitute engineering services, does not produce sealed or certified deliverables, and does not replace applicable codes, standards, manufacturer documentation, or the judgment of a licensed professional responsible for the design. Verify all results independently before use. Report a problem with this result.