Replace CMOS battery

thewolfe · Post by **thewolfe** » Mon Jun 01, 2009 2:51 pm

My time is not staying correct. I have a CR2032 battery.

Should replacing it solve the problem and is there anything I need to do before replacing it?

Krom · Post by **Krom** » Mon Jun 01, 2009 3:14 pm

If the CMOS battery was dead, BIOS would usually also be forgetting its settings. If the clock is just getting consistently off by exactly one or any whole number hours, check and make sure your windows timezone settings are correct. Otherwise it would be a good idea to write down all the important BIOS settings that aren't at default, then replace the battery.

thewolfe · Post by **thewolfe** » Mon Jun 01, 2009 3:53 pm

Clock is set to the correct time zone. I'm not sure which are not default so I'll write them all down. Thanks

Tunnelcat · Post by **Tunnelcat** » Mon Jun 01, 2009 4:16 pm

If you're not getting the time off the internet automatically, the clock could be drifting due to a dirty power signal from your power company. My XP computer keeps the time just fine since it's linked to the net for time keeping. But my older computer that doesn't have that feature runs fast all the time.

Definitely write down ALL BIOS settings BEFORE removing the battery. Krom's right, it'll save you a BIG headache.

thewolfe · Post by **thewolfe** » Mon Jun 01, 2009 4:47 pm

I have it set to auto update from the Internet but I guess that may only happen when I turn it on.

Anyway, I'll write down my settings and change that puppy out. Thanks.

Jeff250 · Post by **Jeff250** » Mon Jun 01, 2009 5:19 pm

This is a long shot, but I wanted to share the story more than anything.

I've actually seen benignly written Windows software affect the rate of the system clock, even from a limited user's account, where this shouldn't be possible, speeding up the system clock by up to 2x as fast. I think it has something to do with buggy system calls, but I was more interested in coding around the issue than understanding it at the time. I actually ran into it developing Java code:

http://bugs.sun.com/bugdatabase/view_bu ... id=4500388

Software such as azureus has been known to trigger this issue on Windows too. I think that this could make for an interesting practical joke on a Windows admin in the right circumstances though.

thewolfe · Post by **thewolfe** » Mon Jun 01, 2009 5:23 pm

All seems to be well. Do I need to save my BIOS settings now that the computer is running or could something happen later?

I have recorded it and could use the tape again unless it would be a good thing to keep.

Duper · Post by **Duper** » Mon Jun 01, 2009 6:24 pm

If you are having issues with your time in Windows, it's a fair bet that it's not you CMOS. Windows keeps time separate from your BIOS.

Also, if your battery was going out, it would be DEAD before you noticed anything. When a battery dies, you loose all the info in the BIOS as Krom stated, but when you boot, you will KNOW because it will forget what kind of drives you have and you will have to go into the CMOS and reset everything and then you will be able to get on with your bootup ... until you shut down again and you will have to repeat the process. I know this from experience.

Under normal conditions, you don't have to mess with your time settings except when you install windows. ... or unless it's a laptop and you're traveling and you want the clock to match the time zone you're in. If you have secondary software to \"keep your time updated\" ..for pete sakes, get rid of it! If there is anything that Windows Can do is keep time well.

Interesting bug Jeff, I could have some fun at work with that.