A watch battery, button cell, silver button cell, or coin cell is a small form-factor battery designed for use in wrist watches, pocket calculators, hearing aids, and similar compact portable electronics products. They are compact and have long life. They are usually a primary single cell with a nominal voltage between 1.5 and 3 volts. Common anode materials are zinc or lithium; common cathode materials are manganese dioxide, silver oxide, carbon monofluoride, cupric oxide or mercuric oxide. The circumferential wall of this type of battery is part of its positive (+) terminal.International standard IEC 60086-3 defines an alphanumeric coding system for "Watch batteries". Examples of this code are batteries coded CR2032, SR516, and LR1154 where the letters and numbers in that code indicate the following characteristics.
code | Letter
L Manganese dioxide
S Silver oxide
P Oxygen
C Manganese dioxide
B Carbon monofluoride
G Copper oxide
"L", "S", and "C" type cells are today the most commonly-used types in quartz watches, calculators, small PDA devices, computer clocks, and blinky lights.
Its package's size is identified by a three-to-four digit code, preceded by the letter "R" to indicate a round cell. The first 1–2 digits indicate the outer breadth of the battery (in millimeters, rounded down), and the last two digits indicate the overall height (in tenths of millimeters, rounded down). Examples:
CR2032: 20 mm diameter, 3.2 mm height
SR516: 5.8 mm diameter, 1.6 mm height
After the package code, the following additional letters may optionally appear in the type designation to indicate the electrolyte used:
S: sodium hydroxide electrolyte
P: potassium hydroxide electrolyte
no letter: organic electrolyte
An appended letter "W" states that this battery complies with all the requirements of the IEC 86-3 standard for watch batteries.
code | Letter
L Manganese dioxide
S Silver oxide
P Oxygen
C Manganese dioxide
B Carbon monofluoride
G Copper oxide
"L", "S", and "C" type cells are today the most commonly-used types in quartz watches, calculators, small PDA devices, computer clocks, and blinky lights.
Its package's size is identified by a three-to-four digit code, preceded by the letter "R" to indicate a round cell. The first 1–2 digits indicate the outer breadth of the battery (in millimeters, rounded down), and the last two digits indicate the overall height (in tenths of millimeters, rounded down). Examples:
CR2032: 20 mm diameter, 3.2 mm height
SR516: 5.8 mm diameter, 1.6 mm height
After the package code, the following additional letters may optionally appear in the type designation to indicate the electrolyte used:
S: sodium hydroxide electrolyte
P: potassium hydroxide electrolyte
no letter: organic electrolyte
An appended letter "W" states that this battery complies with all the requirements of the IEC 86-3 standard for watch batteries.
