An AAA or triple-A battery is a standard size of dry cell battery commonly used in low-drain portable electronic devices. A zinc–carbon battery in this size is designated by IEC as "R03", by ANSI C18.1 as "24", by old JIS standard as "UM 4", and by other manufacturer and national standard designations that vary depending on the cell chemistry. The size was first introduced by The American Ever Ready Company in 1911. [1]