CMOS Battery Replacement

It's hard to think in this day and age that there is a battery on your motherboard. Yet you will find it
nestled on the board supplying power to hold your settings and date/time in memory. This is called the
CMOS battery. CMOS battery replacement is a relatively easy procedure.
The most used type is the Lithium (Li). This battery is round and about the size of a coin. These batteries
can be found at most retail stores and electronic stores.

So how do you know when it's time to change it out?

5. Use a small flat head screw driver to gently pry it out. If
you can get a finger nail on it, there's usually a tiny spring
loaded tab to push aside while you pry it out.

6. Determine the type of CMOS battery. Check the model
number and voltage so you will know what to use for your
CMIOS battery replacement. Lithium batteries look very
much alike but can have different characteristics.

7. Snap the new battery in. Place it with the small circle
side down and just give it a gentle push. It should snap right
in to its holder.

8. Replace the PC Cover and plug the power cord back in.

9. Boot up your PC. You may get some warnings that
"Settings have changed." Most computers will start back up
with the default Date and Time. Just click on your Clock
Manager or right click the Clock on your Tool Bar to reset
the day and time to current.
* There's an "Internet Time" tab under "Properties." Check
that so your computer will sync with the internet for your
time.

As I already stated, and you may now know for yourself, it
is an easy operation to complete a CMOS battery
replacement.

Okay, so you've come to the realization that it's not really
noon, maybe because it's dark outside. Here's how to do a CMOS
battery replacement.

1. Turn off your computer and unplug it from the wall.

2. Locate the screws that hold the left-hand side panel of your computer in place.

3. Remove the Cover according to the PC manufacturer's instructions. Lay the computer on its side with the motherboard
facing up.

4. Locate the CMOS battery. Depending on what model PC you have, there may be different types of batteries but typically it
will be Lithium and they're easy to find on the motherboard. It looks like a silver coin simply mounted on the Board.

It could be that the computer clock seems to be losing
time after the system has been shut down. The
computer will lose time. Or you could become victim to
one of these error messages:

BIOS CMOS checksum error defaults loaded
BIOS CMOS battery low cmos wrong memory size
No operating system
CPU overclocking failed
New CPU has been installed