CMOS battery draining fast

**MatrixPC** · 10-01-2007, 10:02 AM

I found that the CMOS battery in my carPCs are draining a lot faster than the home PC. The one in the Supra, I been replace 3 batteries in the pass 4 years. The one in the Matrix been replace 2x in almost 3 years. The home PC is still on it 4 years original battery and the PC isnt' on that often now.

Isn't it the environment the carPC in contribute to the fast dying of the CMOS battery? The first time it happen kinda freak me out but as I get use to it now. Either I have to replace the battery soon or having to press whatever key it is to continue to use the carPC (little inconvenience).

Do you guys have this problem?

**Mr Beta** · 10-02-2007, 07:13 AM

I've not had any experience with it but I've read that if your cmos batteries get too hot, it shortens their lifespan.
A hot car might kill a battery quicker than a battery in a cool house.

No proof to back it up though.

**Nomader** · 10-02-2007, 07:47 AM

sometimes in the summer..my pc looses time

i have not given much attention to it..but i believe it is the heat..so i guess it does shorten the life span

**b10hazard** · 10-02-2007, 03:08 PM

also, your home computer is using the 5volt constant to keep the clock up to date, most dc-dc PSUs cut that off after the motherboard has shut down. the battery is used when the that 5 volts isn't available, in your home, thats only when the PC is unpluged, the car, every time its shut down.

**Nomader** · 10-02-2007, 03:20 PM

Originally Posted by b10hazard

also, your home computer is using the 5volt constant to keep the clock up to date, most dc-dc PSUs cut that off after the motherboard has shut down. the battery is used when the that 5 volts isn't available, in your home, thats only when the PC is unpluged, the car, every time its shut down.

i guess you are right..

**Phatsacks** · 10-02-2007, 03:24 PM

That's good info to have and expect.

So anyone with a CarPC for 2+ years, should most likely be agreeing with these results?

**john1701** · 10-02-2007, 03:49 PM

yep, had at one time a full mobo in the car and battery kept dying, its now in the house running a server, havent changed the batt since, i agree 100%

**MatrixPC** · 10-02-2007, 03:54 PM

I think it's a combination between environment (heat) and power source cut off.
So, if anyone has some funky message (cmos check sum) come up during boot, CMOS battery is the first suspect.