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

All batteries can be charged. However, they will explooode if they are charged above their stated voltage.
Rechargeable batteries have a switch to prevent them from charging beyond the safe voltage. That is why they cost extra. Rechargeable batteries of 1.5 volts charge up to only about 1.3

You can buy a universal charger which sets the required voltage so it shuts off before it exceeds the safe voltage. My physicist friend had one and didn’t buy batteries for ages.
DO NOT TRY THIS AT HOME.