Cmos Battery Failure. The CMOS (Complementary Metal Oxide Semiconductor) chip on your computer remembers everything like the disk drive, time and date, etc., so you don't want to have a CMOS battery failure. The CMOS battery is a small, round battery that lets you store the day, time, and month on your computer.
CMOS stands for "Complementary Metal Oxide Semiconductor." How do I know my CMOS battery failed? Your PC occasionally turns off or doesn't start. I replaced the CMOS battery with a new one, and powered the PC back on and I got the same two error messages at the BIOs screen.
Dead CMOS battery will rarely do this anyways.
Let's take a look at a few signs of a CMOS battery failure.
Your PC occasionally turns off or doesn't start. The CMOS (Complementary Metal Oxide Semiconductor) chip on your computer remembers everything like the disk drive, time and date, etc., so you don't want to have a CMOS battery failure. If you have a Laptop CMOS battery error like RTC battery is low press enter to set date/time.