The CR2016 lithium cell, like any lithium coin cell, is rated at 3.0V, which is why it is sometimes called a CR2016 3V lithium battery. The four digits in the battery designation actually give the dimensions of the coin cell. The first two digits, 20, mean that the coin cell is 20mm in diameter. The last two digits, 16, mean that the CR2016 cell is exactly 1.6mm high. Lithium is the name of a metal used in the manufacture of the CR2016.