T23 Backup Battery

[Andersonjoe711]

Hey, What is the purpose of the backup battery, and how do I know if I need to replace it? Also, when I was tinkering around, and taking it apart, i noticed what looked like 2 watch batteries as well. What are all these extra batteries doing? And when do I need to replace them, if at all?

[tfflivemb2]

The backup battery stores your CMOS/BIOS information, which also includes the Date and the Time.

The battery itself IS a watch battery. It is a CR2032.

Knowing whether or not you need to replace it can be tricky. Generally if the Date and Time needs to be reset, then that would be a sign of needing to replace the battery. Sometimes, the battery should be swapped out to eliminate it from being suspect in weird startup problems.

[Stargate199]

There is only one backup battery as far as I know, and that is the yellow thing that sits under the main battery. Those other batteries might be capacitors of some sort.

[rkawakami]

<snip>... i noticed what looked like 2 watch batteries as well.

If you go to this thread:

http://forum.thinkpads.com/viewtopic.php?t=37956

and download the two pictures I have linked in the first post (top side and bottom side w/legend), you will see a T23 motherboard. Where are the two "watch batteries" you are talking about?

[Andersonjoe711]

Where are the two "watch batteries" you are talking about?

When you take the cover off of the Memory slot, there's 2 little metal cylinders, they look like little batteries.

[Andersonjoe711]

Thanks tfflivemb2! At least now I'll know when and what to replace it with!

[rkawakami]

When you take the cover off of the Memory slot, there's 2 little metal cylinders, they look like little batteries.

Those are two large capacitors. I think they are for the audio input/outputs in that area.