Battery Changing

[Earl Partridge]

Not an XP question but since the more knowledgeable folks hang out
here...

If the on-board battery dies, you lose your CMOS settings, right?
And if you replace the battery, even before it dies, you're also going to
lose those settings, right?

Can the battery be replaced while the machine is running so as not to
lose those settings?

Earl

 

[Malke]

Not an XP question but since the more knowledgeable folks hang out
here...

If the on-board battery dies, you lose your CMOS settings, right?
And if you replace the battery, even before it dies, you're also going to
lose those settings, right?

Can the battery be replaced while the machine is running so as not to
lose those settings?

No. If you have configured your CMOS in a particular way, then Google for
software using "back up CMOS software". Most people will not need to do
anything except set the date/time.

Malke

 

[Sharon F]

Not an XP question but since the more knowledgeable folks hang out
here...

If the on-board battery dies, you lose your CMOS settings, right?
And if you replace the battery, even before it dies, you're also going to
lose those settings, right?

Can the battery be replaced while the machine is running so as not to
lose those settings?

Earl

Do not replace the battery while the computer is running. This would be
dangerous for your computer and your person.

If you do not have system documentation that tells the default and
recommended settings for your computer, make notes of your current
settings. Shutdown. Replace battery. On first power up after battery
replacement, immediately enter the BIOS set up screens. Restore your
settings. Save changes and Exit. Allow Windows to boot normally.

If taking notes on settings sounds daunting, there are alternatives.
Searching the internet, you should be able to find a program that can print
out your BIOS settings. Or use a digital camera to take pictures of each
screen.

 

[Ken Blake, MVP]

If the on-board battery dies, you lose your CMOS settings, right?

They get reset to the defaults.

And if you replace the battery, even before it dies, you're also
going to lose those settings, right?

No, not necessarily. You normally have a few minutes (usually at least 15,
and sometimes more) before the info is lost)

Can the battery be replaced while the machine is running so as not to
lose those settings?

That was be an extremely dangerous thing to do. You run th erisk of
elecrocuting yourself and also of frying the motherboard.

Personally, I always make a hard copy of all my CMOS settings and keep it
available just in case.

 

[JS]

Shut down the PC, remove the power cord, open the case, make sure there is
plenty on light (flashlight) and locate the battery, verify that you have
the correct replacement (most are type 2032).
Notice the way the battery is installed and were/what is used to keep the
battery in place.

Now the trick is to remove the old battery and insert the new one in less
than 15 seconds (although as Ken said you may a minute or more).
Place the new battery near the PC and then using a non metallic object
(strong plastic tooth pick) pop out the old battery and insert the new one.

Note that some PCs have and option to save the current BIOS configuration to
a floppy, if yours does then make a backup just in case.

JS

 

[Guest]

I will usually WAD-a piece of TAPE up for a STICKY-and dab it at the worn
battery..plucking it out..I will use my bare fingers to POP the New one in
place..quickly.

 

[Phil Weldon]

'Earl Partridge' wrote, in part:
| If the on-board battery dies, you lose your CMOS settings, right?
| And if you replace the battery, even before it dies, you're also going to
| lose those settings, right?
_____

If you have a fairly modern system using at least an ATX power supply,
turning the power off with the front panel switch does NOT turn off the
power to the CMOS, system clock, and a few other components. ATX power
supplies provide a 'Standby' +5 volts whenever plugged in to the AC mains.
This 'Standby' power is used to switch full power on and off, power circuits
like those mentioned before, and provide functions like 'Wake on LAN'.

If the CMOS/clock battery is dead, you would have already lost the CMOS
settings if you have unplugged the system or used the back panel on/off
switch (if one is present) since the battery died.

If you remove the battery while 'Standby' power is ON, then the CMOS and
clock functions will be preserved.

As for safety, on of the reasons for the move to the ATX power supply is
that ALL AC mains power is confined within the power supply case. Only the
DC voltages of +12 V, +5 V, +3.3 V, -5 V, and -12 V appear outside the power
supply case.

If you are not experienced working on electronic equipment, I'd suggest that
you unplug the system from the mains before working inside the system case.
As others have suggested, it is easy to back up the CMOS settings, and the
default settings will be loaded from the BIOS if the CMOS settings are lost.
That will be enough for you to boot your system and restore the settings,
either from a floppy or CD-ROM, or manually from a written list.

Phil Weldon

| Not an XP question but since the more knowledgeable folks hang out
| here...
|
| If the on-board battery dies, you lose your CMOS settings, right?
| And if you replace the battery, even before it dies, you're also going to
| lose those settings, right?
|
| Can the battery be replaced while the machine is running so as not to
| lose those settings?
|
| Earl
|
|

 

[Bruce Chambers]

Not an XP question but since the more knowledgeable folks hang out
here...

If the on-board battery dies, you lose your CMOS settings, right?
And if you replace the battery, even before it dies, you're also going to
lose those settings, right?

Can the battery be replaced while the machine is running so as not to
lose those settings?

Earl

Actually, if you replace the CMOS battery *before* it has died, and do
so quickly enough, you might not lose anything. It often takes several
seconds for the CMOS (which is nothing more than a fancy diode) to
discharge and "forget" everything.

But the battery most definitely should not be replaced while the
computer is running. In fact, keep your hands out of the computer
cabinet entirely while power is applied.


--

Bruce Chambers

Help us help you:



They that can give up essential liberty to obtain a little temporary
safety deserve neither liberty nor safety. -Benjamin Franklin

 

[Bernard W Joseph]

Do not replace the battery while the computer is running. This would be
dangerous for your computer and your person.

If you do not have system documentation that tells the default and
recommended settings for your computer, make notes of your current
settings. Shutdown. Replace battery. On first power up after battery
replacement, immediately enter the BIOS set up screens. Restore your
settings. Save changes and Exit. Allow Windows to boot normally.

If taking notes on settings sounds daunting, there are alternatives.
Searching the internet, you should be able to find a program that can print
out your BIOS settings. Or use a digital camera to take pictures of each
screen.

I don't know about other guys, but I have replaced about a dozen
batteries while the computer was running. Didn't lose a thing, not even
the hair on my arms.

If you are really concerned about danger, shut the computer off, with
clip leads put a battery in parallel with the old one, install new
battery, remove clip leads, turn on computer. I've had to do that when
battery replacement meant replacement of a board.

Bernard

 

[Don Schmidt]

I don't think there is any voltages above 12 vdc outside of the power supply
and thus by not going into the power supply box one would be safe from any
voltage danger.

 

[Sharon F]

I don't think there is any voltages above 12 vdc outside of the power supply
and thus by not going into the power supply box one would be safe from any
voltage danger.

Fair enough. Still, it only takes one quick short to trash a component.
Prefer to advise conservative safety over reading someone has unwittingly
zapped some hardware.

 

[Don Schmidt]

I wasn't endorsing changing the battery with the computer on; just giving an
opinion that there wouldn't be any danger of personal injury due to
electrocution.

 

[Ken Blake, MVP]

Sharon F wrote:

I don't know about other guys, but I have replaced about a dozen
batteries while the computer was running. Didn't lose a thing, not
even the hair on my arms.

That's like saying you rode in a car without a seatbelt a dozen times, and
weren't hurt. Nobody said there was a guarantee of getting killed every
times you did it, just there was a danger. Having survived doing something
dangerous, even multiple times, doesn't make it any less dangerous.

Replacing the battery while the computer is running is nothing less than
foolhardy, in my opinion. It's dangerous and entirely unnecessary.

 

[Ken Blake, MVP]

I don't think there is any voltages above 12 vdc outside of the power
supply and thus by not going into the power supply box one would be
safe from any voltage danger.

The comonly-believed thought that only high voltages are dangerous is not
correct. Current, and other factors, can be more significant than voltage.
Read, for example, http://en.wikipedia.org/wiki/Electric_shock

 

[Phil Weldon]

'Ken Blake' wrote:
| The comonly-believed thought that only high voltages are dangerous is not
| correct. Current, and other factors, can be more significant than voltage.
| Read, for example, http://en.wikipedia.org/wiki/Electric_shock
_____

You should be hesitant to cite wikipedia for any critical information.
Especially when the cite does not bear on the subject.
The case is that ATX specification motherboards are supplied +5 V regardless
of the position of the front panel ON/OFF switch. All AC mains voltage is
confined to the inside of the power supply case.

Phil Weldon

| Don Schmidt wrote:
|
| > I don't think there is any voltages above 12 vdc outside of the power
| > supply and thus by not going into the power supply box one would be
| > safe from any voltage danger.
|
|
| The comonly-believed thought that only high voltages are dangerous is not
| correct. Current, and other factors, can be more significant than voltage.
| Read, for example, http://en.wikipedia.org/wiki/Electric_shock
|
| --
| Ken Blake - Microsoft MVP Windows: Shell/User
| Please reply to the newsgroup
|
|

 

[Don Schmidt]

Ken,

I don't think 12 DC is capable to injure an individual, just not enough
voltage to pass it through the human body. i.e, touching the negative
terminal of a car battery with the left hand while touching the positive
terminal with the right hand. There is ~600 amps available but the 12 volts
just cant get the current through the human body. Now if you put ten
automobile batteries in series, that will definitely fry one; still ~600
amps but with 120vdc dynamite!

 

[Ken Blake, MVP]

Ken,

I don't think 12 DC is capable to injure an individual, just not
enough voltage to pass it through the human body. i.e, touching the
negative terminal of a car battery with the left hand while touching
the positive terminal with the right hand. There is ~600 amps
available but the 12 volts just cant get the current through the
human body. Now if you put ten automobile batteries in series, that
will definitely fry one; still ~600 amps but with 120vdc dynamite!

I don't pretend to be an expert on this, but I won't argue the point, or try
to convince you. But from what I've read, depending on other factors, such
as the amount of current, 12V not only can injure, but in the right
circumstances, can kill.

 

[Ken Blake, MVP]

Ken,

I don't think 12 DC is capable to injure an individual, just not
enough voltage to pass it through the human body. i.e, touching the
negative terminal of a car battery with the left hand while touching
the positive terminal with the right hand. There is ~600 amps
available but the 12 volts just cant get the current through the
human body. Now if you put ten automobile batteries in series, that
will definitely fry one; still ~600 amps but with 120vdc dynamite!

Here's a link that looks pertinent:
http://66.102.7.104/search?q=cache:...uted+by+car+battery&hl=en&gl=us&ct=clnk&cd=10

or http://tinyurl.com/etmnt

It states "So, a Computer that is plugged in and turned on will not
electrocute you when touching any of the boards or chips inside the case
because you are dealing with low voltages (12 volts or less), and high skin
resistance (2000 ohms or more) which limits the amperage. " which certainly
seems to support your point of view. But then it goes on to say "When
handling computer parts inside a case, use only one hand. Do not wear a
grounding strap. This makes it less likely for electricity to pass from one
hand, through the heart, and out the other hand in the event of an
electrical short somewhere." which seems to support the view that it is at
least possible, if not likely to hurt yourself.

I'll continue to take the prudent point of view, and keep the power off and
the computer unplugged whenever my hands are inside the case, and continue
to recommend that others do the same. It certainly safeguards the computer's
components, and at least *may* save my life.

 

[Don Schmidt]

I don't skydive either. <G>

don

Here's a link that looks pertinent:
http://66.102.7.104/search?q=cache:...uted+by+car+battery&hl=en&gl=us&ct=clnk&cd=10

or http://tinyurl.com/etmnt

It states "So, a Computer that is plugged in and turned on will not
electrocute you when touching any of the boards or chips inside the case
because you are dealing with low voltages (12 volts or less), and high
skin resistance (2000 ohms or more) which limits the amperage. " which
certainly seems to support your point of view. But then it goes on to say
"When handling computer parts inside a case, use only one hand. Do not
wear a grounding strap. This makes it less likely for electricity to pass
from one hand, through the heart, and out the other hand in the event of
an electrical short somewhere." which seems to support the view that it is
at least possible, if not likely to hurt yourself.

I'll continue to take the prudent point of view, and keep the power off
and the computer unplugged whenever my hands are inside the case, and
continue to recommend that others do the same. It certainly safeguards the
computer's components, and at least *may* save my life.

 

[Jim Macklin]

With the computer OFF, the hard drive isn't powered and thus
the data is probably safe from a spike or random signal.
Unless you unplug the power cord however, there is always
some level of "keep alive" current on the 5 volt side of the
mobo.

If you are worried, open the BIOS and note the settings,
they are easy to reset, restore. Rarely will you find a
situation where the default BIOS is a problem. If the
battery is dead, it means it is very old, since the power
line and power supply are always hot and the battery isn't
being used, it will last the shelf life.

There is a capacitor that will keep the settings, with the
system OFF, long enough to change the battery. Just be sure
to have the new battery, of the correct number, out of the
package, read the manual or examine the battery clip so you
know what to do and don't take all day.

Some old mobo have the battery soldered in place



message | Bernard W Joseph wrote:
|
| > Sharon F wrote:
|
| >> Do not replace the battery while the computer is
running. This would
| >> be dangerous for your computer and your person.
|
| > I don't know about other guys, but I have replaced about
a dozen
| > batteries while the computer was running. Didn't lose a
thing, not
| > even the hair on my arms.
|
|
| That's like saying you rode in a car without a seatbelt a
dozen times, and
| weren't hurt. Nobody said there was a guarantee of getting
killed every
| times you did it, just there was a danger. Having survived
doing something
| dangerous, even multiple times, doesn't make it any less
dangerous.
|
| Replacing the battery while the computer is running is
nothing less than
| foolhardy, in my opinion. It's dangerous and entirely
unnecessary.
|
| --
| Ken Blake - Microsoft MVP Windows: Shell/User
| Please reply to the newsgroup
|
|