Battery Expiration Dates. Learn about alkaline battery life, AA battery life, 9V battery life and more.
Since the life you’ll get from a battery is dependent on when the battery was made, not necessarily when it was put into service, it’s important to know the date code so you can be sure the battery you buy is “fresh” and hasn’t been sitting on the shelf for a couple of years.
Batteries operate on a chemical reaction. The reaction continues even as the battery sits outside the device. If it is left to sit long enough, it will eventually burn itself out.
Energizer and Duracell battery cases are stamped with the manufacture date, not the expiration date, so do not be concerned if you receive a shipment with the case stamped 6 months or a year on the back. The batteries inside are still fresh – and that’s where you need to look – on the actual battery to determine AA battery life, 9V battery life, as well as all alkaline battery life. (Rayovac Battery cases are marked with the expiration date – also noting the AA battery life, 9V battery life, etc.)
Manufacture and expiration dates most likely have little to do with each other. It will probably depend on the manufacturer. The expiration date is usually the date past which the manufacturer will not guarantee that full life is left. It is probably a conservative date, so most batteries will have a full life after that time. Better batteries will show a later expiration date. Alkaline battery life is so dependent on how the batteries are used, and there are no standards.
Button Cells – One important piece of information that missing…there is no battery expiration date code. Nothing is written or printed on the packaging or on the battery.