Even small electronic devices need some type of battery for maintaining power. But fitting a useful battery inside a compact device can often be a major challenge for developers. That is where coin batteries come into play. As the name implies, coin batteries are shaped like coins. Their ultra-thin profile makes them perfect for small devices where size is a concern. This can include devices such as key fob and compact door and window sensors.
The CR1620 batteries get their name because they have a diameter of 16mm across and a total depth of 2.0mm. The "CR" portion of the name comes from the International Electrotechnical Commission (IEC). The IEC uses the CR prefix do identify that the batter uses "lithium manganese dioxide chemistry". A CR123 battery supplies 3-volts of power to an electronic device, and it uses lithium ion technology. Most of these batteries can store power for up to eight years.
As stated earlier, CR1620 batteries are lithium coin batteries. Because coin batteries are often very similar in terms of size, it can be possible to interchange the sizes. However, it is always recommended to use the appropriate battery size. Even if another size will work, that does not mean that it is optimal. Using a different size could make the connection loose, and the overall life expectancy for the device may not last as long.
The best use for CR1620 batteries is inside compact devices that require a power supply with a very thin profile. Key fobs often use coin batteries since they need to easily fit inside one's pocket. Some smaller door and window contacts may also use the CR1620 batteries. An example of a device that uses CR1620 batteries is the Honeywell 5800RPS door sensor. This compact recessed sensor needs a small battery in order to maintain its hidden profile.