Eli5 What is the difference between regular aa batteries and the rechargeable ones? Why can’t the disposable ones also be charged

Question

One would imagine they are identical but this is obviously not the case.

In: 6

Answer 1

There are lots of completely different chemical reactions that can produce electricity.

With some of them, you can “undo” the reaction by forcing electricity through them the other way.

With some of them, you can’t.

“AA” refers to the size of the battery, and there’s an expectation that they are somewhere around 1.5 volts. There are “AA” batteries available with many different chemicals.

To be commercially successful, a battery has to either be cheaper or better than all it’s competitors. (Or have better marketing, but we’ll ignore that for now).

So there is a market for both cheaper single-use AA batteries, and more expensive rechargeable AA batteries.

(See [https://en.wikipedia.org/wiki/AA_battery#Comparison](https://en.wikipedia.org/wiki/AA_battery#Comparison) for a list of the main types of AA battery).