CMOS battery for Thinkpad

Replacement CMOS battery for IBM ThinkPad made from standard CR2032

Home made CMOS pack
Home made CMOS pack

I have a possible need to reprogram some van keys and the affordable programmer that might be capable requires a Laptop running Windows XP. So I set about adding windows XP to an old IBM Thinkpad. In doing so I quickly found out the CMOS battery inside was as flat as a pancake!

The one fitted had a tiny connector fitted to some short lead and a CR2032 in some heat shrink. I located some cheap enough on a popular Chinese online store but decided to just make one from stuff hanging around.

The spot welder I then found was also lacking juice. So while that was on charge I hooked up a couple of series AAA cells and completed the installation of Windows XP.

A day later I puled the nickel strip tabs from the original CMOS, and soldered the original connector. I added some heat shrink tuber to each lead to prevent the joins from shorting to anything else. Then I spot welded to reclaimed nickle strips to the CR2032 cell. After that I put a larger piece of heat shrink over the cell. Then I installed the new batter in the same location as the original. It is a tight fit but it works fine.