An ampere hour (abbreviated Ah, or sometimes amp hour) is the amount of energy charge in a battery that will allow one ampere of current to flow for one hour.

A milliampere hour (mAh) is 1,000th of an Ah, and is commonly used as a measure of charge in portable computer batteries. The mAh provides an indication of how long the PC will operate on its battery without having to recharge it.

25 Jan 2011