My PowerBook G3 Firewire (Pismo) has one of its two batteries that won't
take a charge. It has been in the right bay for a while and was getting
used first so it has way more cycles than the other one.
One of the little freeware utilities reported numbers for max charge and
actual charge that were in the thousands for the good battery, but less
than 50 for the bad one.
The bad battery does discharge and recharge within this small range.
Apple has some utilities for such problems for the earlier PowerBooks
but expressly says that they don't ...