Is your computer’s time resetting when you power down? Check the CMOS battery

If the time and date on your computer resets back to a date like January 1st, 1990 at 12:00PM, then you might have a CMOS battery issue. This article will explain how to find and swap out the CMOS battery in your computer.

What is CMOS?

CMOS standards for complementary metal-oxide semiconductor, and it’s a small chip that is responsible for storing information such as the system time and other hardware settings. The CMOS must retain power at all times in order to retain the information stored, that’s why it has a dedicated battery. The battery that powers the CMOS is a CR2032, a small coin-like battery which can last up to 10 years without issue.

CMOS Battery CR2032

You might not notice that your system date has changed, especially considering that most computers can try to sync with the regional date and time once they are booted and connected to the internet. Another way to check if your CMOS battery is failing is to watch for any errors such as these during bootup:

  • CMOS Battery Failure
  • CMOS Checksum Error
  • System battery voltage is low
  • CMOS Read Error

If you notice any of these errors on your bootup screen then it might be time to replace your CMOS battery. How can you do that? Follow the quick and easy steps below to replace your CMOS battery and get your computer back to working optimally.

How to replace your CMOS battery

The first thing you will want to do prior to starting these steps is to obtain a CR2032 battery. They are fairly popular batteries, and you can generally find them at most electronic stores and even large retail stores like Target or Walmart.

CR2032 Battery for CMOS
  1. Disconnect your computer from all of the cords that are currently attached.
  2. Set the computer on its side with the motherboard side against the ground.
  3. Open up your computer case by unscrewing the screws on the back
  4. Remove the side of the case and locate the CMOS battery on the motherboard
  5. Remove the existing CMOS battery from its holder
  6. Install your new CR2032 battery in the exact same way the original one was installed (Do not flip the battery or install it backwards)
  7. Put the computer case back together and plug everything back in.
  8. Restart the computer and you should be good to go.

If the problem persists and you continue to receive error messages, you may have installed the battery backwards, or it might not be pressed in all the way. Check to make sure the batteries ‘+’ side is facing up towards you, and press firmly on it to make sure it is seated in its holster properly.

If this doesn’t resolve the issue or if you are having other issues, then contacting a PC repair service such as Dave’s Computers is a great way to save time and hassle. Utilizing a PC expert can eliminate any potential for possibly messing up your computer or causing bigger issues while self-repairing your PC. So if you’re a New Jersey local, check out their store at 415 Amwell Road, Suite 103Hillsborough NJ 08844 or visit them online at

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