The CMOS battery is a very small battery, but it plays an important role in the computer’s operation. It powers the laptop’s BIOS firmware, which initiates the boot process. Over time, this battery can go bad (or fail), which can lead to various problems in the computer’s operation. Some of them are the following:
- Having issues in the Booting Process
- Time and Date will be reset (every time, you will boot)
- The motherboard might produce a beeping noise
To avoid these problems, it is important to replace the CMOS battery, which is relatively easy and takes only a short time.
How to replace CMOS battery in Desktop
- Find the CMOS battery on the motherboard (it has the same appearance as mentioned in the image).
- On a specific side of the battery holder, there will be a tenon used to fix the battery and hold it tightly.
- Press down the Tenon with a screwdriver (or with your nail, if not available).
- When it is pushed down, the battery will automatically pop up.
- Remove the old battery and install a new one.
Desktops always use the battery with the following model number: CR2032 3V Lithium Battery (manufacturer can be different, but the model number would be the same).
How to replace CMOS Battery in Laptop
- Remove the bottom cover from your laptop and check the CMOS Battery on the motherboard.
- Disconnect the built-in battery cable from the motherboard, then disconnect the CMOS battery cable from the motherboard. Please note that you must disconnect the built-in battery cable before you can touch other components. Otherwise, static electricity may damage your notebook.
- Usually, the CMOS battery is fixed with double-sided tape on the palm rest, which can be separated from it by applying a little force.
- Remove it and replace it with a new CMOS battery.
The CMOS battery of each laptop is different. To check the CMOS battery model, you can remove the bottom cover to check it or ask the laptop manufacturer. You can also search for your laptop in the MyFixGuide store to find the CMOS battery.
“Desktops always use the battery with the following model number: CR2032 3V Lithium battery (manufacturer can be different, but the model number would be the same).” A BR2032 will last a lot longer, especially if the computer is powered down for a lot of the time. They have slightly different chemistry that is better suited to a very low current draw over a long period of time. CR batteries are optimized for short bursts of high current draw (e.g. in a garage door remote). BRs are significantly more expensive and difficult to get hold of, and motherboard manufacturers do not use them as OEM components. But if you replace a CR2032 with a BR, it should be good for 7-10 years under typical circumstances.