the CMOS battery is usually located/accessed by removing the keyboard.
Acer don't seem to want to share that kind on data so here's some stuff which may help, but its for an ASPIRE 3000:-
Before you begin, back up your data and remove the battery. CMOS Bios
will be lost but will reset on restart.
Open the laptop computer's
screen and lay it back as far as it will go. Be careful not to stress
the screen and cause any damage, but press it hard if needed.
Press a flathead screwdriver under the front of the plastic
bar lining the back of the laptop's keyboard. Pry the bar up slightly
and hold it with one hand.
Pry up the other side of the bar with the flathead
screwdriver and fully pull out the bar. Keep its ribbon cord connected
and set the bar on the laptop's screen.
Remove the two Phillips screws securing the computer's keyboard.
Then, slide the keyboard up and out to remove it. Again, do not remove
its ribbon cord, and set the keyboard over the laptop's touch pad.
Remove the four screws securing the cover plate over the
motherboard and remove it as well.
Locate the CMOS battery at the bottom right corner of the
Remove the battery by prying it up gently with the flathead
screwdriver. Then, replace the battery with a new one of the exact same
Replace all the parts in the laptop in the reverse order that
you removed them. -Battery Replacement
This didn't quite do the job, the Aspire was a bit of a so and so. So here's how I changed it on a 3000:-
Acer Aspire 3000 CMOS battery replacement.
Before going any further, you need to know that Acer have done you no
favours, this laptop is especially designed to raise revenue for Acer
and other laptop technicians. This is a fiddly task and you could do
with 3 hands.
1) The cmos battery is on the motherboard about half way down the left
hand side, turn your laptop upside down and you should see a locking
screw for the optical drive, its just inboard from that screw under the
bottom cover plate.
2) The motherboard on the ACER Aspire 3000
is upside down, so it faces the bottom plate or table it sits on.
3) The battery is a 3v Maxell ML1220 or equivalent. About the size of
your little finger nail.
Before dismantling your laptop, disconnect the power supply and remove
the battery. Then read these instructions thoroughly, make sure you are
happy with what you are going to do.
1) Ensure you've got plenty of work space, a plate/dish for the
screws and I like to work on a newspaper so I can swivel it all around
without scratching anything.
2) Close the laptop, remove the screws from the 3 hinge covers.Open
laptop until flat, gently prise off the top backplate. It includes the
hinge covers, buttons etc and continues down as far as the top of the
Start at one end gently teasing/prising it upwards until it comes free,
there are no connections.
3) Removed the 2 screws holding the keyboard down, lift the keyboard
gently and place it upside down on the mouseplate, don't break the
4) Remove the three remaining screws from under the keyboard, one of
these is a second optical drive lock screw. Replace the keyboard in its
bed, close the laptop and turn it over.
5) Remove all screws and covers from the bottom plate. Remove HDD and
the Optical drive, but leave CPU, RAM and WIFI in place. There are 2
further screws one in the battery well and one in the HDD well,remove
6) Very gently, from the side of the laptop where the DVD drive sits,
prise the bottom plate away. It won't come away completely. There's a
speaker connector at the front at the other end. Bear in mind you'll
probably need the lid open as well.
7) Once you have the bottom plate prised far enought apart, you should
be able to see the battery, on the motherboard about half way down just
about where the back of the DVD Drive would sit. Its in a white plastic
mounting, and should be able to flick it out with your finger nail or a
screw driver. It may be a good idea to get a second pair of hands to
hold the laptop while you replace the battery.
Remember the negative side of the battery sits in the mounting, Positive
8) Re-assemble laptop, reverse order to dismantling.
9) Keep fingers crossed whey you re-boot.