An AA battery (also called “double A” or Mignon battery) is a standard size of a single cell cylindrical dry battery; in the IEC system it is designated size “R6” and “15” by ANSI . AA batteries are commonly used in portable electronic devices. An AA battery is composed of a single electrochemical cell that may be either a primary battery (disposable) or a rechargeable battery. The exact terminal voltage and capacity of an AA size battery depends on the cell chemistry. AA batteries account for over 50% of general battery sales. 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 gives several different designations for cells in this size, depending on cell features and chemistry.