CMOS Battery Lifespan

[Waryth]

How long do they last?

I play no life for about 12 hours a day at most and some cases leave it on when downloading or doing an anti-virus scan.

Is it normal to have CMOS Battery dying for every 1 year and replace it every time?

As my statement above, does the usage drains the CMOS Battery faster than it should?

I'm not sure if its my MOBO's issue or CMOS Battery but everytime I replace the battery, it seems to boot up my PC again.

[Bad 💀 Motha]

The cmos battery is used when the PC is powered off. They should last 3 to 5 years usually.

The ones that ship with boards are usually just cheap ones is all, and they've also been actively in use since the board left the factory.

I replace with Energizer CR2032
Usually found in a 5 pack fairly cheap price on amazon

[Astraea Kisaragi]

Generally people switch out motherboards earlier as the battery dies - assuming the PC is active. In normal use the battery should last at least 5-8 years. As much PC is used, that less the battery drains.
I never replaced in my active PCs but I replaced a PC my father brought home from workplace - a Intel E8500 left without juice for 5+ years, what my mother now uses for browsing.

[r.linder]

If your PC is on more than it's off, then it's going to last probably until you get a new motherboard entirely. The battery is only in use when the PC is off.

[SeriousCCIE]

I have two motherboards where I need to replace them every six months.

I have other motherboards that took over 5 years.

The differences between them are the boards requiring a frequent replacement are "workstation" class motherboards with many additional features; the ones not requiring frequent changes are just typical motherboards.

I have used the same as Bad Motha, and Sony's as well. The Sony CR2032 seem to last a little longer than the energizers in my abusive professional workstation motherboards, but otherwise, neither type has expired in my regular motherboards after first putting them in, a few are going on 3 to 4 years now.

I've never seen a cmos battery last 8 years, but it's possible. One system I have, that I do not normally ever turn on (its even in a box) I last turned on a few years ago and it's CMOS said it was 2009 despite it being 2016 at the time. The PC was built in the early 00s and never had a battery change. That battery lasted the entire time, but as I saw, it wasn't keeping even close to accurate time, considering the 7 year drift.

[tacoshy]

PC off = disconnected from the wall or using the offswitch on the PSU.

[Bad 💀 Motha]

I've used energizer battery for a replacement though in many used pc that I have sold over the years and even after 5 years, has anyone complained that the system wouldn't post or had reverted to bios defaults due to the battery failing.

Many times I've seen them easily last well beyond what is suggested.

But sure, be my guest, use whatever cr2032 you come across and generally it should be fine. For how long, until it dies is really all anyone can say for sure.

[Waryth]

Originally posted by tacoshy:

PC off = disconnected from the wall or using the offswitch on the PSU.

with the shutdown button on windows, that means its literally still on in the inside or what?

I never touch the off switch on the PSU or remove the plug.

[SeriousCCIE]

I think that you should buy a few 1 packs or a 5 pack of CR2032 (like the energier or sony types mentioned here). They are inexpensive and might even be cheaper in a 5 pack than 3 single packs.

Keep piece of paper taped to the inside of the computer case with the date you change the battery, and maybe a reminder in your calendar or something to swap the battery once a year or so, maybe a little less to prevent it from happening when you don't expect it to be.

It's what I've had to do for the professional workstation boards of mine. They won't even turn on when the CMOS battery is dead, so there's no getting around replacing them, but is is better to be prepared than to be surprised...

Also the shutdown button still provides power to the PC. physically removing the power cable out of the PC or the wall is what "PC off" means.

Chances are if you have it plugged in and turned off, your motherboard just drains the batteries quickly, but at least on a measurable and predictable basis so that you can plan for it.

You can try turning off CMOS bios features and stuff, but it probably won't help make the battery live much longer.

[Bad 💀 Motha]

Originally posted by Waryth:

Originally posted by tacoshy:

PC off = disconnected from the wall or using the offswitch on the PSU.

with the shutdown button on windows, that means its literally still on in the inside or what?

I never touch the off switch on the PSU or remove the plug.

Stand by mode doesn't keep the bios alive though. So yes even when a typical off situation of the pc being off but plugged in and psu is on, the battery is in use.

When you turn the pc fully on, the psu keeps the bios alive, not the battery.

Changing bios settings does nothing to the life of the battery. The bios settings are stored in the bios rom. The battery vs psu power is just a dynamic power phase switching that occurs. Doesn't matter if the motherboard is 20 years old with a 128kb rom or a brand new one with a rom that is many megabytes in size. The battery draw will be the same strain.

[Rumpelcrutchskin]

If you dont use your PSU off switch it can easily last 5-7 years.

[h_LordEC[no-VC]]

Originally posted by Bad 💀 Motha:

Originally posted by Waryth:

with the shutdown button on windows, that means its literally still on in the inside or what?

I never touch the off switch on the PSU or remove the plug.

Stand by mode doesn't keep the bios alive though. So yes even when a typical off situation of the pc being off but plugged in and psu is on, the battery is in use.

When you turn the pc fully on, the psu keeps the bios alive, not the battery.

Changing bios settings does nothing to the life of the battery. The bios settings are stored in the bios rom. The battery vs psu power is just a dynamic power phase switching that occurs. Doesn't matter if the motherboard is 20 years old with a 128kb rom or a brand new one with a rom that is many megabytes in size. The battery draw will be the same strain.

Standby mode and the system being off but PSU plugged in will be drawing power (5v) for the CMOS Ram from the PSU.

The CMOS battery is used when the power supply is switched off or the PSU is disconnected from the power outlet or motherboard.

As far as how much power is drawn by the CMOS battery, the voltage would be the same but the actual power draw would be different... the difference in lifespan wouldn't be noticeable though.

CMOS battery is expected to last 5-7 years with the system plugged in and PSU switch on, doesn't matter if the system is powered on or not.
CMOS battery lifespan without a PSU connected is expected to last ~3years.

[tacoshy]

Exactly - standby mode or PC shut down will still draw power from the PSU and not CMOS

[[☥] - CJ -]

Ive been using the same battery since 2012, so that should give you an idea.

Lifespan of the battery would depend on the quality of the battery and how often the battery actually gets used.

I have actually wondered recently and in the past when/if i should change it though.

[DevaVictrix]

I've never had to replace one! The PC gets sold or binned before that happens. I'm on my forth motherboard in 20 years.

[El poco nuez del muerte]

Originally posted by SeriousCCIE:

I've never seen a cmos battery last 8 years, but it's possible.

Sure is. My current system was built in July 2010. Or that is when the MB was put in anyway. So far I haven't seen signs of the battery getting weak. I'm curious to see how long it will last.