Battery life varies with hearing aid styles. Some hearing instruments require more power to function at optimum levels. Digital hearing aids contain sophisticated circuitry to deliver near-to-natural hearing in a variety of environments, and this requires more power than analog hearing aids need. Typically, wearers of digital hearing aids can expect a battery to last from 5 to 7 days. If you experience shorter battery life, your hearing care professional can check the battery contacts in your hearing aids, as well as, test for battery drain. Most batteries have a “shelf-life” of about three years.
Unlike common household batteries such as AA, AAA and 9-volt, zinc-air batteries are activated by the oxygen in the air. Without oxygen, zinc-air batteries can’t power hearing aids.
Before a hearing aid battery is inserted, a sticker must be removed from the back. This sticky tab keeps the battery fresh, and protects the zinc inside the battery from being activated. Once the tab is removed, tiny holes in the battery casing allow molecules of oxygen to enter. The holes are big enough to let oxygen in, but small enough to prevent battery fluid from seeping out. A filter behind the holes also helps thwart leakage. Remember, once you remove the tab, there’s no turning back! Resealing the battery will not stop the activation process and save it. So, be sure to keep the tab intact until you’re ready to use the battery.
Because oxygen must pass through fine holes and a filter, it’s absorbed slowly. That’s why it’s important to wait a full minute before you insert the battery and close the battery door after you’ve removed the tab. If you don’t wait, the battery may not absorb enough oxygen to properly power your hearing aids.