Battery Capacity Calculator


The battery life calculator provides an estimate of how long a battery will survive, taking into account the nominal battery capacity as well as the average current that is being drawn from the battery by a load. The capacity of a battery is most commonly expressed in terms of ampere-hours (Ah) or milliampere-hours (mAh), although watt-hours (Wh) may also be used.

Calculator for Battery Capacity Formula and Equations:

Battery Capacity in mAh = (Battery life in hours x Load Current in Amp) / 0.7

Battery Capacity = (Hours x Amp) / Run Time %


Battery Capacity = in mAH

Battery life = in Hours
Load Current = Consumption of device in Amperes
0.7 = Battery Cycle life considerations – Run time

Ideal Battery Capacity Formula:

Battery Capacity = Battery Hours x Battery Amps

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Rabert T
As an electrical engineer with 5 years of experience, I focus on transformer and circuit breaker reliability in 110/33-11kV and 33/11kV substations. I am a professional electrical engineer with experience in transformer service and maintenance. I understand electrical principles and have expertise troubleshooting, repairing, and maintaining transformers, circuit breakers, and testing them.