You may have noticed a battery on your motherboard called the CMOS battery, which saves the date, time, and BIOS settings when your desktop is turned off. If you are experiencing issues with your motherboard BIOS and want to reset it or want to replace the CR2032 CMOS battery, we can guide you through the process.

Every battery has a fixed lifespan, and even if you do not use your computer often, its capacity will likely decrease. You can easily replace the battery yourself. It is quite simple, and you can find affordable CMOS batteries on Amazon, Flipkart, or any other preferred e-commerce store.

Additionally, removing and reinserting the CMOS battery can be helpful if you are experiencing BIOS issues. You can reset your motherboard battery by removing and reinserting the CMOS battery with a 5-minute gap.


On a desktop, you do not need any additional tools, but on a laptop, you will need a Phillips screwdriver to remove the GPU or expansion card to access the CMOS battery.

  • You will need a replacement battery. Most motherboards support CR2032 lithium coin cells.
    • If your desktop or laptop uses a MINI-ITX motherboard, you may need a different CMOS battery connected through a wire. Some also support CR1220. Check your CMOS and find the same variant of the coin battery.

Reason for Changing the CMOS Battery

You may want to change your CMOS battery for several reasons. One of the most common reasons is a dead CMOS battery, which causes your system to reset every time you reboot.

  • CMOS checksum error
  • CMOS battery failure
  • CMOS Read Error
  • The system battery voltage is low.

Encountering these issues frequently could potentially indicate that your CMOS battery has depleted. Generally, CMOS batteries have a lifespan of 4 to 5 years.

How to Replace the CMOS Battery on a Desktop

Here are instructions on how to replace the CMOS battery on a desktop. Follow the step-by-step instructions below.

  • Start by shutting down your desktop and unplugging it from the AC power adapter.
  • Press and hold the power button for a few minutes to drain any extra charge on your motherboard’s capacitors.
  • Unmount the front panel in your case.
    • Use a screwdriver to get under the hood and disconnect the battery to continue on a laptop.
  • Now, press down on the latch on the CMOS battery slot (common on most ATX and Micro-ATX motherboards).
    • You may also need to unmount the GPU on some desktops since it is placed under it.
  • Pull out the battery and replace it with a new one, or for resetting the BIOS, wait a few minutes before you reinsert it.
  • Put everything back together and power on your PC.

After doing this, you will see a notification stating that the BIOS settings have been cleared. Proceed forward and reset your system, or you can change the default BIOS. However, you will need to resync your time and date.

Replacing or just removing and reinserting the CMOS battery comes in handy even when you are facing system failure to boost past the BIOS or debug LED lights on the motherboard as they continue to flash after pressing the power button on your PC.