[SOLVED] Nominal value of CMOS battery voltage.

stf92 · 08-23-2011, 02:45 AM

Hi:

My motherboard is an M741LMRT-H. Could you tell me the nominal voltage of the CMOS battery? The processor is a Celeron, and the battery is a lithium one, in case it helps.

If you do not know the exact answer, please tell what is the usual for a desktop PC. Thanks.

garydale · 08-23-2011, 04:35 AM

See http://en.wikipedia.org/wiki/CR2032_battery. The nominal voltage is 3.0 volts.

stf92 · 08-23-2011, 04:39 AM

It's been most kind of you. Thank you.

onebuck · 08-23-2011, 08:29 AM

Hi,

Quote:

Originally Posted by stf92

Hi:

My motherboard is an M741LMRT-H. Could you tell me the nominal voltage of the CMOS battery? The processor is a Celeron, and the battery is a lithium one, in case it helps.

If you do not know the exact answer, please tell what is the usual for a desktop PC. Thanks.

If you are trying to measure the voltage for the battery then be sure to have a load for it. You can use a 1kΩ resistor out of circuit. Or measure the battery voltage in circuit since the CMOS would be a load.

stf92 · 08-23-2011, 09:24 PM

Thank you. Yes, I connected one of the probes of the multimeter to the chassis with a crocodile and touched the battery with the other. This is a machine I haven't used in a lot of time. The multimeter reading was a bit over 1.0v. I wonder if a lithium battery discharges after a long period of not being used.