A story about batteries

[Simpo Two]

Have you ever wondered why battery sizes use A, C and D but not B?

It goes back further than you think! https://en.wikipedia.org/wiki/Vacuum_tube_battery

[Beati Dogu]

When my dad was a boy he’d be tasked with taking the radio’s battery down to a local garage to be recharged. Sounds like it would be one like this.

[Neddy Sea Goon]

HP 7 ? PP 3?