How to read a Interstate battery date code

Decode a battery date code now (runs in your browser).

The rule

A stamped month letter and year digit; the maker’s FAQ gives only one example, C3 for March 2023. Letters A to D read the same under every known table, so they are decoded here. From E on, makers’ tables disagree, and Interstate doesn’t say which one it uses, so the tool shows the candidates.

Source: Interstate FAQ.

Worked examples

Verify the result with the maker or the shop. The year digit repeats every ten years.