Every hearing aid needs a source of dependable power. The source of that power is the hearing aid battery.
Running on air
Hearing aid batteries once had as much as 50% mercury. By the mid 1990’s that level was reduced to 1%. Now hearing aid batteries have absolutely no mercury.
Modern hearing aid batteries use zinc as their major component. The second major ingredient is air, which comes from outside the battery. That’s why some manufacturers label their batteries Z (zinc) or ZA (zinc air). While the number on the battery is important (size 312, for example), the letters are no longer meaningful since all hearing aid batteries are zinc air.
Why don’t my batteries last longer?
Batteries have gotten smaller. The first hearing aid batteries weighed several pounds! Now the most popular batteries (#10 and #312) are about ¼ the size of what was once the standard size (#675). Regardless of size, hearing aid batteries have at least 25% more stored energy than they did even 10 years ago. So why don’t they last longer?
Batteries work harder. Hearing aids today do much more than simply amplify sound. Digital hearing aids now monitor the incoming sound, process speech, control background noise, and cancel feedback-all of which takes battery power. Hearing aids also use wireless connectivity to connect to phones and televisions, and to communicate with each other-and that uses power too.
In other words, while the amount of energy stored in a hearing aid battery has increased significantly, more of that energy is used to process all the sounds around us. As a result, even these improved batteries don’t last longer than batteries of years ago.
Rechargeable batteries are an alternative to traditional disposable battery. Many hearing aids are now available with batteries that last about a day, but are recharged every night. The battery itself doesn’t have to be changed for about two years.