CMOS Battery

CMOS is a short form of Complementary Metal Oxide Semiconductor. It is most important part of computer system. It is also called BIOS battery or Lithium battery. It is used to keeps the computer's date and time consistent and also keeps the BIOS option, the password, running smoothly. This means the BIOS are working even when the computer is OFF.

                 For example, look at the CMOS Battery in below picture.

Fig: CMOS Battery

Full form of CMOS Battery

    C     -     Complementary 
    M     -     Metal 
    O     -     Oxide
    S     -     Semiconductor 


Fig: Full form of CMOS