What happens when your PC's CMOS battery dies?

You might not even have known about this little battery, but you'll notice the effects when it stops working.

By Calvin Wankhede Oct. 26, 2026 8:15 am EST Maryia_K/Shutterstock Add Engadget on Google: Google Discover

Look closely at a desktop computer's motherboard, and you'll notice a small disc-shaped battery that was installed from the factory. This coin-sized battery powers your computer's real-time clock and helps preserve basic hardware-related settings when the machine is turned off.