Replacing CMOS Battery

My machine is roughly 6 years old and I expect to have to replace the CMOS
battery one of these days. Can someone tell me approximately how long I have
after I remove the old battery until I put the new one in without losing the
CMOS settings? On an old, old machine with the box type battery, I had a
few minutes to change it out. Is the same true with the current type?

Thank you very much.

Jack Gillis wrote:

> My machine is roughly 6 years old and I expect to have to replace the CMOS
> battery one of these days. Can someone tell me approximately how long I
> have after I remove the old battery until I put the new one in without
> losing the
> CMOS settings? On an old, old machine with the box type battery, I had a
> few minutes to change it out. Is the same true with the current type?
>
> Thank you very much.

Somewhere between seconds and days. Really. I recall a 486 board that
remained knowledgeable for a couple of days (!!) after the (coin-style)
battery was removed. And a P166 that lost its settings before my fumbling
fingers could swap in a replacement battery.

A capacitor stores the charge that's supposed to ride through a battery
change. Since the old battery is (probably) near its end-of-life, the
voltage on the capacitor at the beginning of the discharge period is
lower than fresh-battery level, so ride-through time is reduced a little.
A larger contributor to discharge time is the health of the electronics
in the BIOS and real-time clock. Old components may have higher than
normal leakage currents that bleed off the capacitor's charge too soon.
The capacitor itself may be the culprit.

So: no guarantees. You know what to do.

Jack Gillis wrote:
> My machine is roughly 6 years old and I expect to have to replace the
> CMOS battery one of these days. Can someone tell me approximately how
> long I have after I remove the old battery until I put the new one in
> without losing the CMOS settings? On an old, old machine with the
> box type battery, I had a few minutes to change it out. Is the same
> true with the current type?
> Thank you very much.

There are freeware programs available that will save the bios settings to
reloadable file on a hard drive or floppy disk.

You might want to post a similar message over in the alt.comp.freeware
newsgroup asking for directions to a program that does this for you.
Include the motherboard/Bios type your computer has.

Others have been known to use digital cameras to snap a picture of the
computer screen while displaying the various BIOS screens.

Jack Gillis wrote:
> My machine is roughly 6 years old and I expect to have to replace the CMOS
> battery one of these days. Can someone tell me approximately how long I have
> after I remove the old battery until I put the new one in without losing the
> CMOS settings? On an old, old machine with the box type battery, I had a
> few minutes to change it out. Is the same true with the current type?
>
> Thank you very much.

in most cases it doesnt matter anyway, bios will detect a bad checksum
and load defaults.


NT

Thank you very much. I will search for such a program.

"GlowingBlueMist" <nobody@invalid.com> wrote in message
news:44da1d00$0$12250$892e0abb@auth.newsreader.oct anews.com...
> Jack Gillis wrote:
>> My machine is roughly 6 years old and I expect to have to replace the
>> CMOS battery one of these days. Can someone tell me approximately how
>> long I have after I remove the old battery until I put the new one in
>> without losing the CMOS settings? On an old, old machine with the
>> box type battery, I had a few minutes to change it out. Is the same
>> true with the current type?
>> Thank you very much.
>
> There are freeware programs available that will save the bios settings to
> reloadable file on a hard drive or floppy disk.
>
> You might want to post a similar message over in the alt.comp.freeware
> newsgroup asking for directions to a program that does this for you.
> Include the motherboard/Bios type your computer has.
>
> Others have been known to use digital cameras to snap a picture of the
> computer screen while displaying the various BIOS screens.
>

GlowingBlueMist wrote:
> Jack Gillis wrote:
>> My machine is roughly 6 years old and I expect to have to replace the
>> CMOS battery one of these days. Can someone tell me approximately how
>> long I have after I remove the old battery until I put the new one in
>> without losing the CMOS settings? On an old, old machine with the
>> box type battery, I had a few minutes to change it out. Is the same
>> true with the current type?
>> Thank you very much.
>
> There are freeware programs available that will save the bios settings to
> reloadable file on a hard drive or floppy disk.

Some of the motherboard manufacturers have such utilities and you might
find one for your specific BIOS.


Richard.

--
Cust. - "Fine salmon in the rivers."
Will Hay - "Grouse on the moors."
Cust. - "Deer in the hills."
Will Hay - "Ah! but cheaper in the towns!"

Interesting. That would make sense and I will do it.

Thanks.

"Richard Brooks" <richardbrooks@vickers-supermarine.com> wrote in message
news:P_Wdnf2-hsSj0EbZRVnyjw@bt.com...
> GlowingBlueMist wrote:
>> Jack Gillis wrote:
>>> My machine is roughly 6 years old and I expect to have to replace the
>>> CMOS battery one of these days. Can someone tell me approximately how
>>> long I have after I remove the old battery until I put the new one in
>>> without losing the CMOS settings? On an old, old machine with the
>>> box type battery, I had a few minutes to change it out. Is the same
>>> true with the current type?
>>> Thank you very much.
>>
>> There are freeware programs available that will save the bios settings to
>> reloadable file on a hard drive or floppy disk.
>
> Some of the motherboard manufacturers have such utilities and you might
> find one for your specific BIOS.
>
>
> Richard.
>
> --
> Cust. - "Fine salmon in the rivers."
> Will Hay - "Grouse on the moors."
> Cust. - "Deer in the hills."
> Will Hay - "Ah! but cheaper in the towns!"

Jack Gillis wrote:
> Interesting. That would make sense and I will do it.
>
> Thanks.

No problem! It would make sense you'd think but then.... ;-)

One nice board manufacturer actually had screen shots of what it should
look like and I do hope you're one of the lucky ones.

Good luck.

Richard.

>
> "Richard Brooks" <richardbrooks@vickers-supermarine.com> wrote in message
> news:P_Wdnf2-hsSj0EbZRVnyjw@bt.com...
>> GlowingBlueMist wrote:
>>> Jack Gillis wrote:
>>>> My machine is roughly 6 years old and I expect to have to replace the
>>>> CMOS battery one of these days. Can someone tell me approximately how
>>>> long I have after I remove the old battery until I put the new one in
>>>> without losing the CMOS settings? On an old, old machine with the
>>>> box type battery, I had a few minutes to change it out. Is the same
>>>> true with the current type?
>>>> Thank you very much.
>>> There are freeware programs available that will save the bios settings to
>>> reloadable file on a hard drive or floppy disk.
>> Some of the motherboard manufacturers have such utilities and you might
>> find one for your specific BIOS.
>>


--
Cust. - "Fine salmon in the rivers."
Will Hay - "Grouse on the moors."
Cust. - "Deer in the hills."
Will Hay - "Ah! but cheaper in the towns!"