Letter Re: Red Dot Sight Battery Longevity

JWR,
I have a red dot sight battery, lithium Energizer CR2032, which was stored in it’s original packaging in a refrigerator since May 1996, almost 13 years ago. I recently opened it and have been testing to see if it would still work, at present I have about 11 hours of use on it. I know this is anecdotal, but the point is, if you use red dot aiming devices and it uses one of these type batteries, it is probably worthwhile to store a good supply of batteries for long term use. Regards, – K. in Texas

JWR Replies: Lithium batteries should be stored in a refrigerator. But reader Shirley A.–who is an audiologist–mentioned that this is a bad idea for zinc air batteries. She notes: “…do not store zinc air batteries in the refrigerator. The batteries are inert until the tab is removed. Once air reaches the hole(s) on the back of the batteries, they become activated, hence “air-activated” batteries. The humidity in a refrigerator will cause the protective tabs to become loose, thus allowing air to reach the holes and activating the batteries.They will all go dead in a short time. Zinc air batteries should be stored in a cool, dry environment, like a dresser drawer. For the same reason, don’t store your batteries (or your hearing aids) in the bathroom.”