The AA battery is the most widely used battery in the world and can be found in hundreds of thousands of devices. The IEC codes for AA batteries include the popular LR6 for AA and HR6 alkaline batteries for rechargeable NiMH batteries. The normal voltage for these batteries is 1.5V, while rechargeable batteries usually provide 1.2V. The new AA lithium batteries provide a much higher capacity for a slightly higher price. Introduced in 1907, the size of the AA battery was standardized by the American National Standards Institute (ANSI) in 1947, but had been used in flashlights and electrical novelties for some time before formal normalization. The nomenclature of ANSI and IEC batteries gives several designations for cells of this size, depending on the characteristics of the cell and the chemistry. Each AA battery has a length of 51mm and a diameter of 14mm. The formats in which the AA battery is available are: alkaline batteries, saline batteries, long-life lithium batteries and rechargeable batteries of different capacities. AA alkaline batteries have a storage life of around 6 years, while AA lithium equivalents last up to 9 years before use. AA rechargeable batteries are now available in NiMH with capacities up to 2850mAh and are also available in the new "pre-charged" technology that allows you to use them directly from the package.
