Ampere-hour

An ampere-hour is a unit of electric charge equal to 3,600 coulombs: the charge transferred by one ampere of current flowing for one hour.

Electric charge: A fundamental property of matter that determines its electromagnetic interactions. The ampere-hour measures an amount of electric charge.
Battery capacity: A measure of the electric charge or energy a battery can deliver under specified conditions. Battery charge capacity is commonly stated in ampere-hours.
Ampere-second: A unit of electric charge equal to one coulomb. It uses the same current-times-time relation with seconds instead of hours.
Charge conservation: The principle that total electric charge in an isolated system remains constant. It constrains where charge counted in an ampere-hour can go.
Electric current: The rate at which electric charge flows past a point. One ampere sustained for an hour defines one ampere-hour.
Milliampere-hour: A unit of electric charge equal to one-thousandth of an ampere-hour. Small batteries commonly use this scaled unit.
Kilowatt-hour: A unit of energy equal to 3.6 million joules. It measures energy, whereas an ampere-hour measures charge.
Direct current: Electric current that flows consistently in one direction. A steady direct current makes the current-times-time calculation straightforward.
Ampere: The SI base unit of electric current. It supplies the current quantity in the unit's definition.
Watt-hour: A unit of energy equal to one watt of power sustained for one hour. Unlike ampere-hours, watt-hours account for voltage as well as charge.

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Peukert's lawRelated: Battery ratings in ampere-hours are conditional; Peukert’s law shows why the load matters.