What is battery capacity?

Battery capacity is the amount of electrical charge a battery can store and deliver. It is typically expressed in ampere-hours (Ah).

A battery with a higher capacity can supply electrical energy for a longer duration under the same operating conditions. Capacity therefore determines the energy available to power a load before the battery reaches its discharge limit.

The available capacity of a battery is not always constant. It varies with several factors, including battery chemistry, temperature, discharge rate, and aging. Higher discharge currents and lower temperatures generally reduce the usable capacity.

Battery capacity provides the reference for determining the amount of charge remaining in a battery and is a fundamental parameter in State of Charge estimation.