Question Time to replace the CMOS battery?

[Nova43]

From time to time, the windows time on my PC speeds up to the point where it's 4 seconds faster than the time servers for EST New York time. Some of the work I do on my PC requires precise timing. So, I find myself periodically resyncing the PC clock with the time.windows.com server in PC settings and then restarting the computer. Is this due to a bad CMOS battery? If so, should I replace it? My rig is older than 11 years old, and I'm not sure when the CMOS battery was last replaced.

Also, I have the vanilla P6T motherboard and the manual mentions something about jumpers for the Real Time Clock (RTC) RAM in CMOS and instructions on how to reset it. Should I bother with this when I replace the CMOS battery? Thanks for your help in advance.

 

[Aeacus]

Replacing CMOS might help or not.

Since, unless you have a quantum clock inside your PC (which, for sure, you don't have), all clocks either fall behind or go forward compared to the atomic clocks used, to keep the time accurate in the whole world.

Though, my PC takes the correct time from the net, automatically. I don't know the frequency of it but thus far, time has been accurate for me. Then again, i don't hunt after milliseconds and getting +/- 30 seconds accuracy is enough for me.

 

[Math Geek]

at 11 years, the battery is probably due to be replaced. won't hurt anything and they are cheap. no reason not to give it a try as a good first attempt at a fix.

they last forever it seems but do start to fail around that 10 yr mark from my experience.

 

[Dexxly_uk]

I would say it should be okay but it's time to replace it when you start getting no posts and checksum bios errors

 

[Nova43]

Thanks for the replies, but should I bother to clear the jumper for the Real Time Clock (RTC) RAM in CMOS as detailed in the manual after replacing the battery? The manual does not identify the battery location on the mobo or discuss anything about the battery including the type required, etc., although a quick Google search says the CR2032 battery is usually used. Thanks.

 

[Math Geek]

i've never had to do such a thing when swapping out the battery, if you do it fast the bios settings can be preserved but if you want to reset it all, then remove the battery for a few minutes and with it unplugged press the power switch a couple times. this will discharge the capacitor and remove all the settings.

CR2032 is the battery used so you found that right

once it is replaced, check in the bios to see what it has stored as the time/date

if it is right, then don't worry. if it is wrong, then resetting the RTC would probably be a good idea.

 

[Nova43]

i've never had to do such a thing when swapping out the battery, if you do it fast the bios settings can be preserved but if you want to reset it all, then remove the battery for a few minutes and with it unplugged press the power switch a couple times. this will discharge the capacitor and remove all the settings.

CR2032 is the battery used so you found that right

once it is replaced, check in the bios to see what it has stored as the time/date

if it is right, then don't worry. if it is wrong, then resetting the RTC would probably be a good idea.

Ok. Thanks.

 

[Paperdoc]

I would advise you NOT to use the RTC jumper pins. In more recent boards that is often called the "Reset" jumper. It does not merely reset the clock. It resets ALL of the info in your BIOS PROM to factory default. That means that all of your custom settings in BIOS Setup would be reset, and you'd have to go in there and set them again to what you want. In fact, it's a good idea to go into BIOS Setup now and write down any custom settings, like which HDD to boot from, what type of video card you are using (if any), etc. Keep that for some future time when this info does get lost and needs to be re-established.

FYI, the most clear indicator that your battery is worn out and requires replacement is if your system's clock loses time completely when it is shut down. In normal operation the clock is powered from the main power supply when your system is on, and the battery is not used then. It is used only to maintain the clock operation AND any stored custom BIOS Setup settings when your system is off. If the battery is dead, both the time AND your custom settings will be lost any time your system is off for a while. Most commonly if that battery is functioning but weak, the clock will run SLOW when the system is off. But yours tends to gain time. MAYBE your mobo just has a clock system that gains time slowly.

In the Windows app where you can force the computer to sync with the Windows time service, there are settings to have time set automatically for you. If you turn these on, Windows will check with its time service periodically and correct your clock with reasonable accuracy. BUT such clocks are NOT totally accurate, so if you need accuracy of better than one second, do the manual update you have been using. Alternatively, from time to time (no pun intended) I go to an accurate on-line time source and use its info to manually reset my clock to within a fraction of a second.

 

[Nova43]

I would advise you NOT to use the RTC jumper pins. In more recent boards that is often called the "Reset" jumper. It does not merely reset the clock. It resets ALL of the info in your BIOS PROM to factory default. That means that all of your custom settings in BIOS Setup would be reset, and you'd have to go in there and set them again to what you want. In fact, it's a good idea to go into BIOS Setup now and write down any custom settings, like which HDD to boot from, what type of video card you are using (if any), etc. Keep that for some future time when this info does get lost and needs to be re-established.

FYI, the most clear indicator that your battery is worn out and requires replacement is if your system's clock loses time completely when it is shut down. In normal operation the clock is powered from the main power supply when your system is on, and the battery is not used then. It is used only to maintain the clock operation AND any stored custom BIOS Setup settings when your system is off. If the battery is dead, both the time AND your custom settings will be lost any time your system is off for a while. Most commonly if that battery is functioning but weak, the clock will run SLOW when the system is off. But yours tends to gain time. MAYBE your mobo just has a clock system that gains time slowly.

In the Windows app where you can force the computer to sync with the Windows time service, there are settings to have time set automatically for you. If you turn these on, Windows will check with its time service periodically and correct your clock with reasonable accuracy. BUT such clocks are NOT totally accurate, so if you need accuracy of better than one second, do the manual update you have been using. Alternatively, from time to time (no pun intended) I go to an accurate on-line time source and use its info to manually reset my clock to within a fraction of a second.

Thanks for your reply. I'll heed your warning and not use the RTC jumper pins. Actually, I noticed this morning that the windows time is actually 1 second slower now. So maybe the CMOS battery is weak. Either way, I'm just going to replace it. Regarding the time settings, I do have the auto update option enabled. I might have to resort to periodic manual time setting if the battery replacement doesn't fix the issue. Thanks.

 

[Karadjgne]

Or maybe has nothing to do with your pc. Windows will automatically set time/date according to what your ISP uses as a time server, so it may very well be nothing more than a discrepancy between whatever you use to check time, and whatever the ISP is saying the time is, plus any residual lag from slow nodes, heavy traffic, etc.

 

[Paperdoc]

Karadjne raises a valid point. You may have options to choose what time source your computer uses for auto updating its time. I'm in Canada and use the NRCC Web Clock at

Web clock (Official times across Canada) - National Research Council Canada

nrc.canada.ca

It includes a system to estimate and display network delay (how long it takes for their time to reach you and be displayed) so you can estimate how accurate your local display is. Right now it says my clock is slow by 0.82 sec, and network delay is 0.03 to 0.08 sec.

 

[Nova43]

Thanks for the replies. There isn't an option in time/date settings to choose a custom time server, but I find third party sync utils to be more reliable. I just downloaded and installed the free Karenware Time Sync utility for Windows 10.