How do i remove the cmos battery on acer M52211

Press F2 (during POST) to enter the BIOS utility. Or if you want to clear the cmos, just remove the removable coin shaped battery for some ten minutes to do the same effect as "clear cmos jumper".

All laptops have a CMOS, or "Complementary Metal Oxide Semiconductor," battery.
The main purpose for the CMOS battery is to keep the system time, date and BIOS settings even if the computer is turned off or the main battery dies.
Individual Acer Aspire laptop models differ somewhat, but the general steps are the same when replacing a dead CMOS battery.Preparation

Read through the owner's manual for your particular Acer Aspire laptop to determine what kind of CMOS battery you need.
Purchase the battery through Acer or a local or online computer parts dealer.
Turn the laptop off and unplug it.
Also unplug any external hard drives, cameras or other external devices.
Turn the laptop over (bottom facing up), then touch something metal to remove static charge.
Removal
Remove the Phillips screws that secure the motherboard cover (refer to your owner's manual if necessary), then release the cover from the clips on the bottom of the plastic casing.
Lay the cover aside, then locate the CMOS battery cable on the right side of the motherboard. Unplug the cable, then remove the battery.
Installation
Plug the new CMOS battery cable into the motherboard.
Slide the battery partially under the laptop casing to hold it in place, then align the cover with the slots on the bottom of the laptop housing.
Replace the screws, then turn the laptop back over.
Settings
Plug the laptop in and turn it on.
Enter your BIOS (usually by pressing "F1," "F2," F10" or the "Delete" key) before the operating system loads.
Follow the BIOS prompts or refer to your Acer Aspire owner's manual to reset your time, date and desired system settings.
BIOS Reset
Any time the CMOS battery is unplugged for more than a few seconds, your BIOS will be reset to the default manufacturer settings.
If you make any changes to the BIOS that cause problems with your Acer Aspire, unplug the CMOS battery for 3-5 seconds to correct the problem.
http://support.acer.com/us/en/default.aspx


Acer aspire laptop battery replacement
http://www.youtube.com/watch?v=mQTZ1AUR0uw

Step 1:
The Acer Aspire stores the password in a component called the complementary metal-oxide semiconductor. This component is integrated into a random access memory chip embedded on the motherboard. The CMOS holds data that the basic input/output system - a critical software utility that controls how the computer operates at startup - accesses when the computer boots. If the BIOS detects that a password is registered in the CMOS, it will prevent the computer from booting until the user enters the password correctly. Depending on which model of Acer Aspire you own, you may be able to clear the CMOS manually. Contact Acer before attempting to clear the CMOS, as opening the computer without permission could void your warranty. Desktop Models Some Acer Aspire desktop models come with a jumper that is used to clear the password and other settings stored on the CMOS. This jumper is located on the motherboard and is often found next to a label such as "JBIOS1" or "CLR_CMOS." To clear the CMOS using the jumpers, turn off the computer, disconnect the power cable and remove the case cover. Remove the jumper shunt from pin 1 and pin 2; then place the shunt on pin 2 and pin 3. Return the shunt to its initial position after 10 to 15 seconds. If the Aspire doesn't come with a jumper to reset the CMOS, the CMOS can be reset by removing the lithium coin-cell battery instead. Removal is accomplished by pushing down on the tab securing the battery to the motherboard and lifting the battery out of its slot. Leave the battery out for 24 hours, and then return it to its original position with the positive sign facing up. Laptop Models b> Resetting the CMOS password on an Acer Aspire laptop is much more difficult than resetting the password on a desktop. Disassembly steps vary from model to model, but on most models, you'll have to take apart the computer to access the CMOS battery. Don't take apart the notebook if you don't have experience disassembling PCs. After turning off the computer and disconnecting the AC adapter, take out the battery (different from the CMOS battery). All visible screws must then be removed from the bottom of the notebook. Remove all components stored to their separate compartments on the base of the notebook. Turn over and open the PC. Lift up the switch cover and remove the screws securing the keyboard to the PC, if any are visible. Remove the keyboard. Remove the screws securing the monitor to the hinges, and then set the monitor aside. Disconnect all visible cables connected to the motherboard; and then remove the screws from the top cover. Remove the top cover to reveal the motherboard. Locate and then remove the CMOS battery. Leave it out of the notebook for 24 hours; then reinstall it and reassemble the Acer Aspire. Other Options b> If removing the CMOS battery fails to clear the password, or if you don't feel comfortable with the idea of opening your computer, you might be able to gain access to the computer using a backdoor password. These special passwords were implemented to allow technicians to access locked computers. Not all models recognize backdoor passwords. Most Acer Aspires use the Phoenix BIOS, and backdoor passwords for this BIOS include "BIOS," "CMOS," "phoenix" and "PHOENIX." All of these passwords are case-sensitive.

Hi
I am giving you another model for dis assembling and from this way you can change your cmos battery.

http://www.insidemylaptop.com/take-apart-acer-aspire-5520-laptop/

Remove the CMOS battery from socket and change .
For Purchase
http://www.buy.com/sr/searchresults.aspx?loc=33409&sid=48

http://www.bizrate.com/travelmate-cmos-battery/?sc=1

http://www.buy.com/retail/searchresults.asp?qu=cmos+battery+for+Acer+TravelMate+4150LCi+PC+Notebook&queryType=home&storeResults=0&cb=338259E-02

Hope it will help you.

Before you start

1) Read through the owner's manual for your particular Acer Aspire laptop to determine what kind of CMOS battery you need.

2) Purchase the battery through Acer or a local or online computer parts dealer.

3) Turn the laptop off and unplug it. Also unplug any external hard drives, cameras, or other external devices.

4) Turn the laptop over (bottom facing up), then touch something metal to remove static charge.

Removal of the CMOS battery

Remove the Phillips screws that secure the motherboard cover (refer to your owner's manual if necessary), then release the cover from the clips on the bottom of the plastic casing. Lay the cover aside then locate the CMOS battery cable on the right side of the motherboard. Unplug the cable then remove the battery.

The battery should look something like this

Plugging the new battery in
Plug the new CMOS battery cable into the motherboard. Slide the battery partially under the laptop casing (somewhere to hold it in place), then align the cover with the slots on the bottom of the laptop housing. Replace the screws then turn the laptop back over.

Finalizing
1) Turn the laptop on.
2)Enter your BIOS (usually by pressing the "Delete" key) before the operating system loads.
3) Follow the BIOS prompts or refer to your Acer Aspire owner's manual to reset your time, date and desired system settings.

Reason: Anytime the CMOS battery is unplugged for more than a few seconds your BIOS will be reset to the default manufacturer settings. If you make any changes to the BIOS that cause problems with your Acer Aspire, unplug the CMOS battery for 3 to 5 seconds to correct the problem.

Please rate this solution by clicking the thumbs up at the top right of this solution. Your rating is much appreciated.
Thanks.

Go to the Acer website, under support and download them.
This link may take you there - Acer 4420 downloads

Unplug AC power. Remove the battery. If there is a CMOS battery (a rarity for laptops now), remove that as well. Press and hold the power button for at least 10 seconds. Replace batteries. Reconnect AC power. Turn on machine. CMOS should be reset to defaults.

the CMOS battery may see when and removed the key board on top of laptop and under cover of the battery you are looking for, careful to leave only the battery