The energy a battery can store and deliver over time is measured in watt-hours (Wh). This value quantifies the total amount of work a battery can perform. As an example, a 12-volt battery with a capacity of 10 amp-hours can ideally deliver 120 watt-hours (12 volts x 10 amp-hours = 120 watt-hours). This means the battery could theoretically power a 12-watt device for 10 hours.
Knowing a battery’s energy capacity is crucial for selecting the correct battery for a particular application. It allows for estimating how long a device can operate before needing a recharge or replacement, preventing unexpected power failures and ensuring efficient energy usage. Historically, understanding battery capacity has been vital in various fields, from portable electronics to electric vehicles, influencing technological advancements and energy management strategies.