eli5; how do (built in) rechargeable batteries in a toothbrush or shaver last for ten years, but AA batteries die after 2 years of use?

Question

I don’t leave my shaver on charge, but my toothbrush is always in the charging holder, so it can’t be a difference cycled charging. I have a 20 year old toothbrush which I use for polishing jewellery, stick it on charge and it’s good to go.

In: 18

Answer 1

Your only using like 5% of the battery in there toothbrush or shaver at a time and then charging it again.

If the battery wears out to the point where it’s at 15% capacity you’ll never really notice if you charge it after every use