I want to replace the battery for my CMOS. How should I do this without erasing everything in my CMOS? Do I jump another battery across the terminals while I pull the old battery out and put a new one in?

Does the CMOS battery only retain the CMOS memory when the computer is powered down ie: can I pull the battery out while my computer is powered on?

Thanks;

Dougie

Hey Dougie,
It is not possible to save your bios setting when changing the battery. Your system needs to be powered off make sure you unplug the power supply as well. The easiest thing to do is copy all of your bios setting down before you switch your battery. Just curious why are you changing your battery out? Do you lose your bios settings when you disconnect your power?

AJZ

Thanks zelkeas;

My daughter is using one of my older computers with Win98, it's almost 5 years old and the battery is the original one. According to what I read, the cmos batterys are good for 2 or 3 years. So I thought I would change it just in cae

Dougie

Makes sense now, chances are with an older motherboard and win98 the only thing you will have to reset in the bios is the system time and date. Heck your battery could already be dead and you wouldn't be able to tell. Unless of course you are overclocking that system.

I'm not sure if thats true about overclocking having any drain on the CMOS battery. It's only purpose is to keep the CMOS memory from erasing when the computer is powered off, nothing else.

My motherboard is an ASUS P2B......

I don't think that ASUS just put that battery in there for nothing at all.

Dougie

I'm sorry let me clarify, if you had made changes in your bios to overclock your system the next time you rebooted with a dead battery you would lose those settings. You are correct overclocking does not have any additional drain on the battery. A computer can run with a dead battery and even without a battery at all. If you have not made any significant changes in your bios you can replace that battery and after doing so reset the time and date in the bios.

AJZ