# Ampere-Hour

An alternative unit of electrical charge. Product of the current strength (measured in amperes) and the duration (in hours) of the current. The quantity of electricity (capacity) of a battery or cell is usually expressed in ampere hours.

Symbol: Ah

One ampere-hour = 3,600 coulombs.

### Battery

Batteries have an Ampere-Hour (Ah) rating. A discharge rate is normally included with this to signify the maximum current that the battery can be discharged at and achieve the rated capacity.

As an example a battery with 60Ah C/20 has a 60Ah capacity when discharged at the capacity divided by 20 which equals 3 Amps in this case.

### milliampere hour (mAh)

One thousandth of an Ampere-hour (Ah), this is commonly used when stating the capacity of rechargeable batteries used in mobile phones.

1 mAh = 3.6 Coulombs

**See also: **Ampere Hour Capacity, Ampere Hour Meter, Battery Capacity, Coulomb.

**Subjects: ** Units