why are there different sized batteries (aaa-D, etc) if they all put out the same 1.5v?

Question

why are there different sized batteries (aaa-D, etc) if they all put out the same 1.5v?

In: 394

Answer 1

Older chemistry before alkaline were pretty weak, so the only way to get a decent current from a cell was to make it bigger.

Now days you can get adapters to let you put an AA or 2 inside a plastic D cell sized thing to let you use cheaper or more convenient cells in things. They work fine if you use alkaline cells in something that only takes Ds because they expected people to use junk cells in it like big heavy flashlights etc.