Button cells are some of the most important power sources as they pack a lot of power in a very small space allowing you to make things smaller and smaller. Watches, calculators, medical instruments and a computer CMOS system all make use of the Maxell CR2032 Battery. This lithium coin cell battery has a power of 3V and a huge 220mAh capacity which can power sensitive electronics for a long time. It has a very light weight but also has a high voltage compared to other coin cells.