how long do CMOS batteries last?
About ten years depending on how use the computer - http://www.computerhope.com/help/cmos.htm
nice link. it earns a bookmark.
the computer is basically on a lot. sometimes 24/7 or longer. It does a lot encoding overnight. and during the day (when someone is on it, its used to do homeowork on or surfing the web)
The real battery killer is leaving the computer unplugged for months on end.Most people don`t do that though.
ah ok cool, thanks a lot for the help
I've got nearly 20 years old lithium batteries still at the voltage marked on them.(Used to save data like on PCs)
It always depends of the mobo also. I have one that drains batteries in about a week when left unplugged. I don't know the average time for the PC battery but I know that the battery wasn't dead on my 1996 jetway j-656(?) motherboard a few months ago.
Oh, and I've got a 1982 tuner with a CR2032(Same as most computers) that still works.
thnx for the info dragonmaster. I have an Asus board P4SD-LA its the ones the HP/Compaq put in their OEM PC's (back in 2000 or so i think)
Uh, why do you want to know that?
They are mostly not failed until your computer can't remember the time and tell that the CMOS was cleared when booting.
cuz of this:
someitmes my BIOS forgets which to boot for XP
when this happens i go check my BIOS and i find nothing in the first boot device section not sure if this is just loose cables or a PSU problem.