Originally Posted by
scarkner
Go to The Source or Best Buy and look at the battery replacements for portable phones (not cell phones, but the cordless phones you use around the house). There are not very many sizes or connectors for these things so you will almost certainly find something that works (might not be the same capacity or pretty, but "works" is the key word.
Also, why do you think the existing one ISN'T working? It's unusual for NiMH to just crap out completely and suddenly.
If it isn't taking a charge, it probably has internal dendrite growth. There is a nasty trick that you can use to fix that.
Take a high quality Duracell 9V battery, hook two wires between it and the terminals of the little NiMH battery. You want to connect it with very short wires and hold them on for not more than about 10 seconds. Run them + to + (red) and - to - (black). About 90% of the time this will clear the internal short in the NiMH and allow it to take a charge again. Don't go longer than 10 seconds or the NiMH will get very hot and it will damage it more (plus could pop open).