How to read a battery label

The code stamped on a battery tells you its chemistry, shape, voltage, and dimensions — all at once once you know how to decode it.

Coin cell codes (CR, LR, SR)

Numbers after the prefix

For the CR/LR/SR coin cell family: the number encodes the diameter and thickness.

• First two digits = diameter in mm. CR2032 = 20mm wide.
• Last two digits = thickness in tenths of mm. CR2032 = 3.2mm thick.

Examples: CR2032 = 20mm × 3.2mm, CR2025 = 20mm × 2.5mm, LR44 = 11.6mm × 5.4mm.

Cylindrical alkaline codes (AA, AAA, C, D)

These letters follow the IEC 60086 standard and map to size classifications. AA (LR6), AAA (LR03), C (LR14), D (LR20). The letter prefix on the IEC code identifies chemistry (L = alkaline, S = silver oxide, C = lithium).

What if the label is missing?

Measure diameter and thickness with a ruler or calipers, then match dimensions to the coin cell cheat sheet. For alkaline AA/AAA, diameter immediately distinguishes them (14.5mm = AA, 10.5mm = AAA).

Common identifiers by region

Related pages

• Coin cell reference pages
• Alkaline reference pages
• Printable cheat sheet