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mitchsc
Feb 21, 2011, 07:15 PM
I want to change my CMOS battery (2032) and was wondering if it is safe (for the PC) if I do it with the power on.

If so, will this save the settings in Setup? (Will power supply keep CMOS powered with battery removed?)

Can't seem to find an answer to this one on Google.

Thanks...

NeedKarma
Feb 21, 2011, 08:32 PM
... was wondering if it is safe (for the PC) if I do it with the power on..Disclaimer: I have never attempted what you are asking.
I can only assume that it would be a bad idea for two reasons: the CMOS battery keeps the internal clock running and the battery is usually located right on the motherboard where it would be way too easy to cause a short-circuit.
Sometimes low-tech is the way to go, in this case taking pictures of the current settings would be the way I would go. But then again upon reboot the default settings would be invoked, how many custom edits have you made to the default settings?

mitchsc
Feb 22, 2011, 07:28 AM
Not too many changes in setup. Boot order (off the top of my head).

I just was wondering if the power supply would cover the CMOS if the battery was removed. I get what you are saying about short circuit risk and it's a good point.

I read that if you change the battery fast enough, the capacitors may keep the settings for a few seconds and it may not default.

NeedKarma
Feb 22, 2011, 07:42 AM
Is it really worth the risk though? If it were me I wouldn't risk it at all.
Having said that be careful, I snapped the battery holding pin/arm/clip thingie off when I did a battery change once, granted it was a really old machine and yours likely isn't set up that way but boy did some choice words emanate from my mouth. Good luck!

mitchsc
Feb 22, 2011, 10:16 AM
Not too many changes in setup. Boot order (off the top of my head).

I just was wondering if the power supply would cover the CMOS if the battery was removed. I get what you are saying about short circuit risk and it's a good point.

I read that if you change the battery fast enough, the capacitors may keep the settings for a few seconds and it may not default.

Curlyben
Feb 22, 2011, 10:57 AM
Unless you have modified the CMOS to any great extent, other than simple boot order, this method would most likely fry your machine.

It is ALWAYS safest when dealing with the internals, to do so with the power OFF.

mitchsc
Feb 22, 2011, 12:49 PM
Alrighty Then.

It's power-off to change battery. :-)

Any thoughts about switching battery fast enough for capacitors to retain CMOS settings (with power off)?

mitchsc
Feb 22, 2011, 07:39 PM
Update for those interested in CMOS battery changes:

I took everyone's advice and unplugged the power cable when changing the CMOS battery.

I did, however, switch out the battery as quickly as I could. It took about 5 seconds. To my pleasant surprise, the CMOS retained all the settings in Setup.

Best of both worlds on this one.

Thanks again to all.