Paul,
Fortunately, these batteries fail rarely and over time. The usual indication
of failure is inability of the computer clock to keep correct time. It is a
good idea to write down all your BIOS settings before you remove the failing
battery.
The batteries are readily available ( I've found them in supermarkets ) and
easily changed. If you pop the old one out and are reasonably quick
replacing it, none of the BIOS settings are lost. I think the worst that
could happen is that all the BIOS settings would revert to the default
settings if you dilly too long putting in the new battery.
Wayne
