In message , Chris Green
writes

They were mostly non-rechargable button cells but I did have one that
had a rechargeable battery. Not usually too difficult to replace,
just take a look inside at the motherboard and it should be pretty
obvious.

OK, I'm missing the obvious. The case is off, and I am looking for a
silver button battery, probably about the six of a sixpence. Could it
be entirely different?
--
Graeme