Have you ever wondered about hearing aid batteries? If you wear any hearing technology, or you know someone who does, the issue of batteries is a common issue. So, for this blog entry, we thought we would provide some information and background on the hearing aid battery.
Nearly all hearing aid batteries are zinc-air batteries. Zinc-air batteries are used for hearing technology because they provide the right amount of power a hearing device needs to operate correctly. Other button-cell batteries (such as those used in watches) cannot provide enough energy for digital hearing technology.
Zinc-air uses oxygen as an ingredient — when the oxygen enters the battery, it reacts with the internal zinc, causing the discharge of battery power. This is the reason for the sticker, or seal, on the vent holes of the battery. Once the tab or sticker is removed, it is impossible to stop the discharge of power. This is also why, after removing the sticker seal, you need to give the battery a minute to sit before placing it into the hearing aid. This allows the voltage in the battery to rise to full capacity so that there are no shortages or problems with the aid at startup.
These batteries come in all sizes and colors. The smallest size, 10, is indicated by the yellow packaging and is used for the smallest hearing aids, such as the CIC (completely-in-the-canal) custom aids. The next size up is 312 (brown packaging). These batteries are probably the most widely used and are often found in ITC (in-the-canal) and RITE (receiver-in-the-ear) technology. Next comes size 13 (orange packaging), which is used for slightly larger aids, such as ITE (in-the-ear) custom devices. The largest battery is 675 and is in the blue packaging. These batteries are used for large power aids.
Keep in mind that as the battery size decreases, so does the amount of zinc in the aids and, therefore, the life span of the battery. Smaller batteries will last 3–5 days, whereas larger batteries will last 15–20 days. It is important to talk to your audiologist about the typical lifespan of your hearing aid batteries. Note that if a battery lasts much less than the average, this could suggest a problem with the hearing aid itself.
Many different environmental aspects can affect the life span of a battery. The biggest culprit is humidity — too much will cause moisture to leak into the vent holes, causing a shortened battery life. Very dry environments with little humidity can dry the batteries out, preventing them from producing any energy. Temperature also can have an effect: colder temperatures (over the winter, for example) can shorten the overall battery life. Additionally, altitude plays a role. Higher altitudes have less oxygen, so the battery has less to use to activate the zinc. Sometimes this does not allow the battery to reach its full power.
One more thing that is important to note with regard to hearing aid batteries: they are dangerous if ingested. It is important to keep batteries away from children and pets!
Source: Audiology Online. Rayovac Hearing Aid Batteries and Important Things To Know. http://www.audiologyonline.com/articles/rayovac-hearing-aid-batteries-important-12293.