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A · B · C · D · E · F · G · H · I · J · K · L · M · N · O · P · Q · R · S · T · U · V · W · X · Y · Z   entire Web this site ampere-hour (Ah) The quantity of charge transported by an electrical current in a given amount of time. It is the current time product at any level of current (Q = I × t). The coulomb is defined as 1 ampere-second, so 1 ampere-hour (Ah) would be 3600 A·s or 3600 C. Most batteries are rated in Ah. A modern AA alkaline cell is rated at about 2.5-2.8 Ah (at the rate 100h rate). Battery capacities can be very sensitive to discharge rate and the characterizing rate will be given by the manufacturer. Nickel-cadmium and nickel metal-hydride cells, for example, are typically characterized at a 5h rate; sealed lead acid cells are typically characterized at a 20h rate. At different discharge rates, the Ah rating will be different. Related category    • UNITS Thanks to Charles Watson for contributing this entry. Also on this site: Encyclopedia of Science Transport Concepts & Designs (partner site) BACK TO TOP