The Battery

Batteries generate electricity through an electrochemical reaction.

A watch battery consists of a single cell. It contains electrodes and an electrolyte that together convert chemical energy into electrical energy. Because different watches have different requirements with respect to voltage, energy and size, batteries vary considerably. The most popular are silver oxide (1.5v) and lithium (3v) cells.

The first miniature batteries were developed during WWII.

The microelectronics industry gave impulse to the development of small batteries. Miniature batteries were developed during World War II by Samuel Ruben and manufactured by P.R. Mallory (this pair later formed the Mallory Battery Company). But they were neither leak-proof nor long-lasting enough for use in watches.

A special battery had to be invented for the first electric watch.

Early efforts to develop a watch battery were conducted by a team of researchers at Hamilton Watch Company (led by chief chemist Phil Lichty, and including Harold Morgan, Wilmer Gingrich and Edgar Long). When these efforts failed, Hamilton joined forces with National Carbon Company (later Union Carbide) in 1954 to develop a battery for Hamilton's first electric watch, the Ventura.