I had a 70 bug, think it was 12V. Some of the earlier ones were 6V IIRC.
Damn battery was under the rear seat, great fun to deal with.
Stone simple car though. Rebuilt mine in the garage. Lowered and installed the engine by myself.
Yeah, I had a 1960 VW Bug, 6 Volt battery. I too installed an engine by myself using only a floor jack. Replaced the aging 36 HP engine with a newer rebuilt 40 HP engine. It had no gas gauge, just a lever above the gas pedal that you turned by foot to switch to the reserve tank, I think it was about an extra gallon of gas.