Use this information only if you aggree to my Disclaimer
Make sure you discharge yourself before messing around inside the computer
case and ensure that the computer is off. In addition only attempt
this if you are reasonably sure of what you are doing.
I accept no responsibility for any damage or injuries caused by following this
advice, you use this at your own risk.
Your first step is to find it. Backup batteries come in many different
forms, and may possibly be inside the clock chip and so will not even be
If you have an in-built battery the whole chip will have to be replaced,
it may be best to consult a professional rather than attempt it
yourself (unless you are a professional in which case why are you reading this?).
If you don't have a battery built in to the chip, then
it should be quite obvious. Things that look like cordless telephone
batteries, ordinary batteries or a big watch type battery (looks
like a coin) etc.
If you are unlucky the battery will be soldered in place, if so this is a
job for someone who is experienced with a soldering iron, do not attempt it
unless you are able to.
If you do want to tackle it yourself then it's probably easiest to snip the
leads off then solder the new battery to the old leads.
Before you replace the battery it's a good idea to test it with a volt
meter to make sure that it is indeed dead. Obtaining a replacement may
be difficult depending on the age of the machine in question. Surplus
parts companies are a good source for older batteries, newer ones should
be readily available.
A final note make sure that you consult the retailer first if in doubt about
which battery to get, make sure that you get the correct voltage (and pinout if