What is the CMOS RAM battery called?

The CMOS RAM battery is commonly referred to as the "CMOS battery." It is typically a small coin-cell battery, often a CR2032 lithium battery, that powers the CMOS (Complementary Metal-Oxide-Semiconductor) memory. This memory stores BiOS settings and system time when the computer is turned off. If the CMOS battery fails, users may experience issues with system settings and time retention.