P.S. I used to repair Macs and as Jeff stated the Macs
wouldn't even
boot without
them.
Needless to say, many repairs that I did were to replace said battery.
One interesting thing I've found though is that the LC-575
with it's 4.5V alkaline PRAM battery will still boot, even if the
battery is dead. I've got a LC-575 mainboard in my Color Classic and
it has a dead (or nearly so) 4.5V PRAM battery but it works fine...it
just complains about the clock everytime you turn it on. I rarely
have much trouble finding the 3.6 Lithium 1/2AA types, though they
are a bit expensive, but I don't have any of the 4.5V types.
Jeff
--
Collector of Classic Microcomputers and Video Game Systems:
Home of the TRS-80 Model 2000 FAQ File
http://www.geocities.com/siliconvalley/lakes/6757