I upgraded my Color Classic to a LC575 motherboard, I noticed after the upgrade that it didn't keep time or memory settings - flat motherboard battery. Usually I would just take it off and run without - but I actually wanted to use this machine.
The Mac LC575 has a weird battery - 4.5v. I couldn't easily find one around. So I made one. This might help someone out there who needs a odd voltage battery for their machine.
Here is the stock battery in place:
It is held in with velcro - nice work Apple!
So most camera batteries are 3v or 3.6v or 6v - nothing 4.5v. But if you open up a 9v battery (not all - only the more expensive ones), you should see some 1.5v AAAA batteries which you can use. They are already wired together.
Split off 3 to give you 4.5v
Solder the wires on (use a meter to get the +/- right), bundle them up with tape, stick on the velcro
and you are done - here it is in place and it works perfectly. Of course, your mileage may vary - but it is a way to get weird batteries made!