mike ring wrote:
Ian Stirling wrote in
:


Number of cells?

Whoops. Just two, so a bit under 3v nominal, and the unit puts about 3.5 v
across them.

Actually, if there is physical room, probably the easiest way is to
buy several AAA NiCd cells, a battery holder, snip off the old leads
high on the battery, and solder on the battery holder.

The package of 2 batteries is about a 16mm dia by 12 mm high cylinder, my
problem is that I haven't come up with anything rechargeable around that
size.

I could bodge some sort of battery box, but it would be nicer to fit them
in the casing.

http://www.cpc.co.uk/
http://rswww.com/
http://www.farnell.co.uk/
Should have results.
I'd check CPC first.