What is "coin battery"? what are they used for?
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.
Electrochemical system The first letter identifies the chemical composition of the battery, which also implies a nominal voltage:
| Letter code | Positive electrode | Electrolyte | Negative electrode | Nominal
voltage | End-point
voltage | L
| Manganese dioxide | Alkali | Zinc | 1.5
| 1.0
| S
| Silver oxide | Alkali | Zinc | 1.55
| 1.2
| P
| Oxygen | Alkali | Zinc | 1.65
| 1.4
| C
| Manganese dioxide | Organic | Lithium | 3
| 2
| B
| Carbon monofluoride | Organic | Lithium | 3
| 2
| G
| Copper oxide | Organic | Lithium | 1.5
| 1.2
|
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.
Package size
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
The numbers in the code correlate with the cell dimensions, being the diameter in millimeters (except for the extra half millimeter in some cases) followed by the height in tenths of a millimeter. Final letters 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. Common applications - Quartz wristwatches, both digital and analog.
- Calculators
- Hearing aids
- Some remote controls, especially for keyless entry
- Backup power for personal computer real time clocks and BIOS configuration data.
- Small PDA devices
- Various electronic toys (tamagotchi)
- Laser pointers
- Small LED flashlights are commonly powered by three button (silver-oxide) cells in series.
- Battery-operated children's books
- Glucometers
- Security tokens
- Cyclocomputers
- Red dot sights and electronic spotting scopes
- Manual cameras with light meters, such as the Pentax K1000
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What is a CMOS battery, and why does my computer need one?
