On Sunday, 1 March 2020 08:53:43 UTC, Jeff Layman wrote:
Clearing out the shed I came across my old 4.8v Challenge Extreme
powered screwdriver, which I hadn't seen for at least 6 years (I use my
Hitachi drill/driver instead). When I opened the box and took out the
screwdriver I accidently touched the trigger and was amazed when the
motor turned. I though it might be the dregs of a charge in the cells,
but I tried again and it turned. In fact, it was not possible to stop it
turning by gripping the shaft.

I have no idea what brand NiMH cells were used in this cheap screwdriver
(Argos), but for the four of them to retain a good charge for 6 years
seems very unusual to me.

I recently found my very old iPad - generation 1. Flat, yes. But charged it up and it appeared to retain charge very well, and worked as well as ever. (Except the ancient version of IOS hits numerous issues if you actually want to do anything with it.) Even leaving it lying around for a few weeks, charge hardly dropped.