The other day I went to the store to pick up a 9 volt battery. As I looked at the section of batteries, I was reminded of something that I already knew, but rarely think about — there are a ton of different batteries. All shapes, sizes and letters.
A. AA. AAA. C. D.
Reminds me of a scantron or a minor league baseball hierarchy. Which got me wondering…
What Do The Letters On Batteries Mean?
Turns out, battery nomenclature is quite complicated. Technical standards for battery sizes and types are determined by organizations such as International Electrotechnical Commission (IEC) and American National Standards Institute (ANSI).
Battery names vary between organizations. For example, AAA or triple-A batteries are known as “R03” by IEC and “C18.1” by ANSI.
The letters/numbers of a battery explain the size, chemistry, terminal arrangements and special characteristics of a battery. To generalize it as much as possible, the letters we are familiar with indicate the height and width. The later the letter the larger the battery. D is larger than C and AA is larger than AAA. AA refers to a batter that is 50.5mm x 14.5mm whereas AAA is 44.5mm x 10.5mm. AA batteries have about three times the capacity of AAA batteries.