Created on: 30 July 2012
Coin batteries and battery holders for beginners in electronics showing a 3V CR2032 button cell and holder as an example. The symbol used for a coin battery in a circuit diagram is the same as for other battery types and is shown on the batteries for beginners page.
A coin battery or button cell is a small coin/button shaped battery. The photos below show an example of a CR2032 3V coin battery and battery holder.
These batteries are very often used to keep a real time clock (RTC) running when the main power to a circuit is switched off.