Button battery size is indicated by a code printed on the battery itself. The code reveals the battery's diameter and height.
Understanding the Button Battery Size Code
The most common coding system uses a three- or four-digit number. This number specifies the physical dimensions of the battery:
- The first two digits indicate the diameter in millimeters (mm).
- The last one or two digits indicate the height in tenths of a millimeter (mm).
For example:
- CR2032: 20mm diameter, 3.2mm height.
- LR44 (also known as AG13): Approximately 11.6mm diameter, 5.4mm height. Often the full designation would be SR44 or LR44, specifying the chemical composition (Silver Oxide or Alkaline, respectively)
Examples of Common Button Battery Sizes
Here are some common button battery sizes and their dimensions:
| Battery Size | Diameter (mm) | Height (mm) |
|---|---|---|
| CR2032 | 20 | 3.2 |
| CR2025 | 20 | 2.5 |
| CR2016 | 20 | 1.6 |
| CR1632 | 16 | 3.2 |
| CR1620 | 16 | 2.0 |
| CR1220 | 12.5 | 2.0 |
| LR44/AG13 | 11.6 | 5.4 |
How to Find the Code on the Battery
The size code is usually printed directly on the button battery. You may need a magnifying glass to read it, as the print can be very small. Look for a sequence of numbers like those listed above.
By examining the code printed on the battery, you can easily determine its size and find a suitable replacement.
