Batteries are toxic if ingested. Be careful to keep all batteries (and hearing aids) away from children and pets. Swallowing a battery is a medical emergency and requires immediate physician care.
A common hear aid device question is "How long does the battery last?" Well, on average, they last 7-14 days if you are to use them 16 hours a day. Hearing aid batteries are inexpensive and are usually less than a dollar each. Most often, the smaller the battery size, the shorter the battery life. The sizes of hearing aid batteries are listed below along with their standard number and color codes.
Today's hearing aid batteries are "zinc-air." Meaning the batteries are air-activated, so a factory-sealed sticker keeps them "inactive" until you remove the sticker. Once the sticker is removed from the back of the battery, oxygen in the air contacts the zinc within the battery, and the battery is "turned-on". Since many of today's hearing aids do not have "off" switches, removing the battery from the hearing aid or opening the battery door, when not in use, assures the device is turned off. Zinc-air batteries have a "shelf life" of up to three years when stored in a cool, dry environment. Storing zinc-air hearing aids in the refrigerator has no beneficial effect on their shelf life. In fact—quite the opposite may happen. The cold air may actually form little water particles under the sticker. Water is made of oxygen and hydrogen. If the water vapor creeps under the sticker, oxygen may contact the zinc and the battery could be totally discharged by the time you peel off the sticker! The best place to store batteries is in a cool dry place.