Coin Batteries
Many coin sized batteries has a model number that starts with the "CR" letters followed by 4 digits. That model number simply indicate the dimensions of the battery NOT the capacity of the battery.
- C = Lithium
- R = Round
- First 2 digits = Diameter
- Last 2 digits = Height
Thus when looking for batteries (e.g. CR2477 battery is used in Bluetooth Beacons), it is important to look at other characteristics (e.g. capacity of 1000 mAh).
Note different manufacturers use different loads (e.g. 6.8k ohm, 7.5k ohm etc.) to measure discharge times, making direct comparison very difficult. For example, the following contains discharge curves for CR2477 batteries with 1000 mAh capacity:
- toshiba.pdf (415.1 KB)
- powerglory.pdf (640.8 KB)
- panasonic.pdf (4.0 MB)