Question: what are aaaa batteries called?
Answer: The AAAA battery (usually read as quadruple-A) is 42.5 mm long and 8.3 mm in diameter. ... This size battery is also classified as R8D425 (IEC) and 25 (ANSI/NEDA). The alkaline battery in this size is also known by Duracell type number MN2500 or MX2500 and Energizer type number E96.