Computer batteries give the motherboard enouth power to store settings in flash memory.
A battery is on the motherboard of all desktop computers that give off power even when the computer is off. The battery provides power to the CMOS, complementary metal-oxide semiconductor. The CMOS technology is important because it runs RAM chips, flash memory chips and other type of memory chips in a computer. Batteries in a CPU should last up to five years, if brand new when installed. When a battery fails, it can have disastrous effects on the computer.
Function
The CPU batter lets the basic internal memory keep track of the calendar date and current time. The battery is the reason why a computer that has been unplugged for an extended period of time knows the current date and time when it is plugged back into the wall outlet. The battery also powers the flash memory in the computer, which contains the startup information. Without power, the computer loses these settings and suffers errors on booting up.
Symptoms
Some computers tell the user that the CMOS battery is low or failing. Watch for CMOS Read Error, CMOS Checksum Error or CMOS Battery Failure messages displayed when starting up the computer. Not all computers have the programming to tell you that the battery is running out. It is common to notice that the date and time is wrong on a computer when the battery is dying. Reset the date and time, but if it keeps occurring, then be prepared to replace the battery. Other symptoms include the computer forgetting which drive to boot up first and unexpected shutdowns that occur for no obvious reason.
Description
The battery on the motherboard of the computer looks like an oversized watch battery. It is a shiny silver circle in a bracket or clip attached directly on the motherboard. The model or part number is usually written on the top of the battery. Most of these batteries are sold in department stores with an electronics section, camera shops and computer parts stores. Most of the battery types are inexpensive, but occasionally a desktop or laptop brand will have a custom-made battery, which costs more than a common battery. Write down the part numbers or take the battery with you to the store to ensure that you purchase the proper battery.
Changing the Battery
Write the CMOS settings from the startup menu is you think your battery is dying. Once the battery dies or you remove the battery, the CMOS settings are lost. The computer will start up using the default settings, which work for most computers unless you have changed them. Turn your computer off, remove the outer cover and locate your battery. Remove the old battery from the clip and replace it with the new battery. Replace your cover and turn on the computer. Enter the computer setup and reenter your computer setting value if needed.
Tags: date time, flash memory, battery dying, battery motherboard, CMOS settings, Error CMOS