Hearing aid batteries are a vital part of the hearing aid itself. Without power from the battery, the whole device is essentially useless. In fact, they’re so important that a lot of people who wear a hearing aid keep a hearing aid battery tester handy. It makes it easy to know when the battery is running low on power. Then they will know to have other batteries on hand to replace it.

The life span of hearing aid batteries will depend on what kind of device you’re using. The smaller hearing aids that fit into the ear canal have a shorter battery life. The reason is that these are smaller batteries and don’t have as much of the power producing components.

The older, more traditional kind of hearing aids utilized mercury batteries to keep them going. These batteries are much less effective than the newer zinc batteries that are popular these days.

Zinc batteries utilize zinc air. This is a combination of the zinc contained inside the battery along with oxygen present outside the battery. The resulting reaction gives power to the battery. They have about twice the life of the conventional mercury batteries.

Zinc hearing aid batteries come with a color coded tab on them. One purpose for this is to be able to tell what size the battery is. However, it also prevents air from entering the battery until you’re ready to start using it.

As soon as the tab is pulled off, oxygen starts to enter the battery. As the oxygen combines with the zinc, the battery becomes activated. For this reason the tab should not be removed until you’re ready to use it so it doesn’t start losing power.

There are four common sizes of hearing aid batteries on the market today. There’s a specific size of battery for every type of hearing aid out there. A number 10 battery with a yellow color code is the smallest you can purchase. The blue labels indicate the largest size available, which is 675. Hearing aids that fit inside the ear canal typically use the smaller sizes. The behind the ear devices will use the larger sized batteries.

The larger sizes are longer lasting since there is room to hold more zinc inside the battery. But they do take up a lot more space. For some people, it’s more important that their hearing aid is discreet than it is to change the battery less frequently.