What Happens When The CMOS Battery Fails?

Iria · Jul 1, 2008, 04:22 PM

Ever wondered what happens if your CMOS battery fails? Most of us know that the CMOS settings are retained whenever the PC is powered, but what happens when you turn off the PC? Will those CMOS settings just go poof? Or will they remain intact as long as the power supply remains turned on?
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Source: TechARP

Matth · Jul 1, 2008, 05:06 PM

Interesting, 4 motherboards tested retained CMOS using ATX standby power, 2 did not.

It can also be inferred from that, that the oneswhich are capable of CMOS retntion using ATX stabdby power, also probably prolong the battery life by not draining it when in the "soft-off" condition.

I'm more surprised that two do not retain.

mike2h · Jul 1, 2008, 06:27 PM

i agree matt. the is no reasom for any mb to lose cmos info while connected to power. of course batteries nowdays usually last the normal use expectancy of any given mb, so faulty batt aside i dont see this as much of an issue.
i personally have never had a battery dying be a prob on any of the dozen+ mb's i have owned. thought it might have been a prob recently but i was wrong.

Judas · Jul 2, 2008, 01:22 AM

blame cheap motherboard or cheap motherboard designs.

i've got intel boards from 20 years ago that still hold thier orginal battery 100% yet.

I've got a board that is less then 3 years old that the battery went dead in

and i've got a few boards where the batteries have been replaced twice in 5 years.

you can blame the batteries sometimes, but not that frequently.

Jul 1, 2008, 04:22 PM	#1
Iria DriverHeaven Extreme Member Join Date: Apr 2004 Posts: 7,275 Rep Power: 87	What Happens When The CMOS Battery Fails? Ever wondered what happens if your CMOS battery fails? Most of us know that the CMOS settings are retained whenever the PC is powered, but what happens when you turn off the PC? Will those CMOS settings just go poof? Or will they remain intact as long as the power supply remains turned on? ____________ Source: TechARP

Jul 1, 2008, 05:06 PM	#2
Matth Flash Banner Hater Join Date: Jun 2002 Location: UK Posts: 3,409 Rep Power: 91 System Specs	Interesting, 4 motherboards tested retained CMOS using ATX standby power, 2 did not. It can also be inferred from that, that the oneswhich are capable of CMOS retntion using ATX stabdby power, also probably prolong the battery life by not draining it when in the "soft-off" condition. I'm more surprised that two do not retain. __________________ Mary had a little lamb, Her father shot it dead Now Mary takes her lamb to school, Between two crusts of bread

Jul 1, 2008, 06:27 PM	#3
mike2h DriverHeaven Extreme Member Join Date: Nov 2002 Location: norcal Posts: 6,483 Rep Power: 89 System Specs	i agree matt. the is no reasom for any mb to lose cmos info while connected to power. of course batteries nowdays usually last the normal use expectancy of any given mb, so faulty batt aside i dont see this as much of an issue. i personally have never had a battery dying be a prob on any of the dozen+ mb's i have owned. thought it might have been a prob recently but i was wrong. __________________