define ampere hour
Part of the Smart grid glossary: 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. An ampere is a unit of measure of the rate of electron flow or current in an electrical conductor. One ampere of current represents one coulomb of electrical charge moving past a specific point in one second. A milliampere hour (mAh) is 1,000th of an Ah, and is commonly used as a measure of charge in notebook computer batteries. The mAh provides an indication of how long the PC will operate on its battery without having to recharge it.