Flat CMOS battery?

[Chris French]

My Mum moved house last year (Sept) and her desktop PC has been out of
use since then (about 4 - 5 months). PC is about 3 1/2 years old IIRC.

Got it back up and running yesterday and when it booted up it came it
with the BIOS setup screen and the date had been reset to something like
2002. after saving the CMOS settings and resetting the date it would
boot up, and did so ok 2-3 more times while I was there.

today she turned it on and it came up with the BIOS screen again.

Am I right in assuming the CMOS battery is lacking in charge? Do these
things recharge when it's turned on, or will it more likely need
replacing?

 

[old jon]

My Mum moved house last year (Sept) and her desktop PC has been out of use
since then (about 4 - 5 months). PC is about 3 1/2 years old IIRC.
snipped
Am I right in assuming the CMOS battery is lacking in charge? Do these
things recharge when it's turned on, or will it more likely need
replacing?

Sounds very likely Chris. If it`s a standard disc type battery, you can
get them in ASDA or Tesco now, on their battery displays.

 

[Noozer]

today she turned it on and it came up with the BIOS screen again.

Am I right in assuming the CMOS battery is lacking in charge? Do these
things recharge when it's turned on, or will it more likely need
replacing?

Very few PC's have every actually recharged the CMOS battery, and that was
years ago.

Just take the battery to your local battery shop. It should be a common
replacement.

 

[Chris French]

today she turned it on and it came up with the BIOS screen again.

Am I right in assuming the CMOS battery is lacking in charge? Do these
things recharge when it's turned on, or will it more likely need
replacing?

Very few PC's have every actually recharged the CMOS battery, and that was
years ago.

Just take the battery to your local battery shop. It should be a common
replacement.
[/QUOTE]
Ok, thanks for the confirmation.

 

[Shep©]

My Mum moved house last year (Sept) and her desktop PC has been out of
use since then (about 4 - 5 months). PC is about 3 1/2 years old IIRC.

Got it back up and running yesterday and when it booted up it came it
with the BIOS setup screen and the date had been reset to something like
2002. after saving the CMOS settings and resetting the date it would
boot up, and did so ok 2-3 more times while I was there.

today she turned it on and it came up with the BIOS screen again.

Am I right in assuming the CMOS battery is lacking in charge? Do these
things recharge when it's turned on, or will it more likely need
replacing?

Yes they do re-charge.There is a residual current applied across the
CMOS to keep the battery healthy.This can be checked using a
Multi-meter.As these batteries are,"Lithium"based they can handle a
certain amount of re-charging.However if the unit has been stored
there is a dis-charge point after usage where they may not be
re-charged.

They are cheap to replace.

HTH

 

[Jerry G.]

After a number of years, these batteries need to be replaced. They are not
very expensive.


Jerry G.

--




My Mum moved house last year (Sept) and her desktop PC has been out of
use since then (about 4 - 5 months). PC is about 3 1/2 years old IIRC.

Got it back up and running yesterday and when it booted up it came it
with the BIOS setup screen and the date had been reset to something like
2002. after saving the CMOS settings and resetting the date it would
boot up, and did so ok 2-3 more times while I was there.

today she turned it on and it came up with the BIOS screen again.

Am I right in assuming the CMOS battery is lacking in charge? Do these
things recharge when it's turned on, or will it more likely need
replacing?

 

[Davy]

Will mention my saga
The hard drive would'nt boot, "Disc failure Please inser
disk" was all I got apart from the POST bios beep as if the HD
was duff or OS corrupted

Would'nt let me do a restore, re-pair in stall or I complete format
trying another HDD was still same. I re-booted bios and all was well
the HDD was asking for the CD so that it could install the 2nd half o
the installation

I replaced the bios battery the old one being down to 2.5V.. Note
never use a analogue meter to measure these or they'll soon be 'flat
always use a digital meter as they have a high-input impedance

I did a complete reformat after changing the bios battery - jus
incase of any corrupted data

Now the reason for the story
All the bios settings was OK and normal except the 5V 30Amp suppl
which was reading 4.3V (some drop for a 30 Amp rail), the time an
date being OK, a bios reboot and a battery change brought the 5V rai
back to normal along with HDD boot....

I would have thought the bios would have 'locked up or reverted bac
to the default settings but it did'nt

All in all I did not need to do a re forma
....."blast....

Dav