With so many battery-powered devices available today, following proper battery storage practices is important for nearly everyone. Chemical batteries are more like loaves of bread than canned vegetables in terms of shelf life, so it is vital that consumers store batteries in ways that maximize their usefulness. The days of throwing loose batteries into a dark drawer along with dozens of other forgotten household items should become a distant memory if maximizing a battery's lifespan is a priority.
One thing a consumer should know about proper battery storage is that temperature is critical. Batteries should not be stored in drawers or shelves near heat sources such as stoves, car interiors, water heaters or refrigerator coils. Excessive heat, especially without ventilation, can cause the interior of the batteries to expand. The stress of expansion can cause the seams to burst open, which in turn releases the battery's alkaline fluid. An unsealed battery is an unusable battery, not to mention a health hazard and a difficult mess to clean up.
Some people may have heard that batteries can be stored indefinitely inside a refrigerator or freezer. This practice does slow down the chemical reactions inside the battery slightly, but not enough to qualify as safe battery storage. The humidity inside a refrigerator can cause batteries to swell and burst open, and frozen batteries must be thawed completely before they can produce any electricity. The excess condensation formed during the thawing process can also damage electronic circuitry.
It is also important to remove batteries from devices before putting them into long-term storage. Batteries can be kept in many appliances for a few weeks without ill effects, but keeping chemical batteries in a series for months at a time can be hazardous. There may be a completed circuit even if the device itself is set to an "off" position. The batteries continue to produce a trickle of electrical power and this in turn generates heat. The batteries may not be able to ventilate this heat, so they develop leaks around their seams.
Proper battery storage in a dry, cool area with sufficient ventilation can extend the lifespan of most chemical batteries. Old batteries which have lost their charge should be discarded separately from regular household trash, much like other chemical substances such as household cleaners, paint and solvents. Old and new batteries should never be combined in any electronic device. When the old batteries no longer produce a useful charge, they should all be replaced at the same time with new batteries.