What is a CMOS Battery?
What is a CMOS Battery?
CMOS stands for “Complementary Metal Oxide Semiconductor.” The CMOS battery powers the BIOS firmware in your laptop.
BIOS needs to remain operational even when your computer isn’t plugged into a power source. That’s where the battery comes in. When your computer gets unplugged, BIOS relies on the CMOS battery for power.
You’ll find CMOS batteries in both laptops and desktop PCs, but it’s used more frequently in a laptop. That’s because laptops are usually unplugged for a longer amount of time than desktop PCs. Most desktop PCs are unplugged from their power source very infrequently.
The CMOS battery gets charged whenever your laptop is plugged in. It’s only when your laptop is unplugged that the battery loses charge. Most batteries will last 2 to 10 years from the date they’re manufactured. The more you leave your laptop plugged in, the longer your battery will last.
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