Button or coin type batteries are primary battery and are often come in cylindrical. They are available in various materials for specific applications. Silver oxide battery are most common button cells that power small electronic devices such as watches, calculators, hearing aids and other small specialty devices. They are available at standard rate of 1.55 volts per cell. They are available in small size, high energy density and long shelf life. Zinc air button cells are used primarily in hearing aids.
lithium button cells are commonly used in glucometer, camera, electric thermometer, calculator, computer equipment as memory backup battery, toys, communication equipment, electronic watches/clocks, card radios, data pack for video cameras etc. They are available in standard 3.0 v, 16.0mm diameter and 2.0mm height. Alkaline manganese cells are common button cells for cameras, calculators, toys and watches. They are crafted with excellent leakage resistance, voltage stability and long shelf life designs. Mercury button cells can be used for watches, pacemakers, hearing aids, microphones etc.