The AA battery is the most widely used battery in the world and can be found in hundreds of thousands of devices. IEC codes for AA batteries include the popular LR6 for AA alkaline batteries and HR6 for rechargeable NiMH batteries. The normal voltage for these batteries is 1.5 V, while rechargeable batteries typically provide 1.2 V. Newer lithium AA batteries offer much higher capacity for a slightly higher price. Introduced in 1907, the AA battery size 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 standardization. ANSI and IEC battery nomenclature give several designations for cells of this size, depending on the characteristics of the cell and the chemistry. Each AA battery is 51 mm long and 14 mm in diameter. The formats in which the AA battery is available are: alkaline batteries, saline batteries, long-life lithium batteries and rechargeable batteries of various capacities. AA alkaline batteries have a shelf life of approximately 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 packaging.