Household Batteries – Providing portable power for decades The Coin or Button Battery The advent of the coin battery or button battery has revolutionised the portable electronics industry. They basically took a double A or Triple A battery and squashed it flat and added more power. These small chrome/silver batteries have a positive (+) top face and sides usually marked with a plus and battery details while the unmarked base is negative (-). They look like a coin or button which is how they got their names. These are found in most watches, car keyless entry fob’s, camera’s, hearing aids, medical devices, toys and all computers so they can maintain their memory and remember what day it is. Size wise they can be up to 32mm in diameter and 1 to 11mm in height. The 3 or mostly 4 digit numbers on the battery is the size of it. If 4 digits, the first 2 numbers are the diameter in millimetres, if 3 digits, it is the first number. The last 2 numbers indicate the height of the battery in tenths of a millimetre. Voltage wise they are usually either 3 or 1.5 Volts and this is normally marked on the battery. Their chemical make-up can be lithium, alkaline, silver oxide and zinc-air. Lithium batteries are prefixed with ‘CR’ which breaks down as C= Lithium, R = Round (coin or button). They are 3V and some are rechargeable. They are lighter and function better in extreme temperatures. Shelf life is 10 years. You will also find some other prefixes in the lithium coin batteries LiR prefix = Rechargeable Lithium Battery, higher voltage 3.2 to 3.9V, Round BR Prefix = Lithium Battery with a different chemical makeup, 2.8 to 3V, Round ECR Prefix = Lithium Battery made by Energiser. Same as CR. Alkaline and silver oxide batteries are only 1.5 Volts. Their prefixes are: LR prefix - L = Alkaline, R = Round (coin or button) SR prefix - S = Silver Oxide, R = Round (coin or button) The zinc-air are used in hearing aids so are very small and the plus (+) is about the only marking on them. They are 1.4 Volts and the packaging should have: PR prefix - P = Zinc-Air, R = Round (coin or button) Visit us online or in your local Repco store for all your battery needs. You may also be interested in: Keyless Entry Novelty Games & Toys Security AlarmsWARNING: Product contains coin or button cell battery. Keep batteries away from children.Coin and button cell batteries can cause severe or fatal injuries in 2 hours or less if they are swallowed or placed inside any part of the body. If you suspect your child has inserted or swallowed a coin or button cell battery, call the 24-hour Australia Poisons Information Centre on 13 11 66