Hearing Aid Batteries: History, Lifespan, Storage, Disposal
With our winter hearing aid battery sale coming to an end soon (January 15), we thought a post about hearing aid batteries would be quite timely. Although small in size, there is plenty to be discussed in regards to hearing aids batteries, so for this post we are keeping it to a short history, lifespan, storage, and disposal.
In the 1930s and 1940s hearing aids needed two batteries that were worn on the body of the user. The batteries used at that time could weigh more than two pounds and were inefficient. The 1950s brought the introduction of transistors, which allowed for a much smaller battery to be used in hearing aids. The silver-oxide battery and mercury battery became the choice for hearing aids. In the 1970s, the hearing aid industry saw the development of the zinc-air button battery. A zinc-air battery offered twice the battery life of its button battery predecessors. Currently, zinc-air batteries are the primary power source for hearing aids. Zinc-air batteries require a constant source of oxygen to stay fully functional once activated by removing a sticker seal.
Hearing aid batteries typically have a long shelf life (up to about four years) if stored properly. They come in the package with a sticker seal on them, which protects the zinc from oxygen. Once the sticker is removed, the battery becomes active. Waiting 2-5 minutes after pulling off the sticker before placing it in a hearing aid will allow the voltage to increase, providing a longer battery life.
Hearing Aid Battery Lifespan
There is no exact battery lifespan for hearing aids because there are many factors that will influence the lifespan of the battery.
Hearing Loss – A person’s degree of hearing loss will impact the amount of amplification a hearing aid provides. As the severity of hearing loss increases, the hearing aid is required to provide more amplification. This increases the amount of current that the hearing aid requires, which reduces battery life.
Hearing aid use – Hearing aids have different amounts of battery drain and can vary based on manufacturer, technology platform, and technology features. The use of wireless streaming from the hearing aid to another device can also shorten the lifespan of battery.
Battery Size - Although many hearing aid battery sizes have come and gone over the years, there are currently four different sizes that are used in the hearing aid market. Smallest to largest, hearing aid battery sizes include: size 10 (yellow), size 312 (brown), size 13 (orange), and size 675 (blue). A smaller battery size results in less amount of zinc in the battery. Less zinc will result in less time that it can power the hearing aid.
Temperature – A lower temperature will result in a lower battery voltage. Extreme cold temperatures can reduce the life of a hearing aid battery. Heat accelerates the chemical reaction that occurs in the battery cell, which will also shorten the battery life.
Altitude – The percentage of oxygen decreases as altitude increases, something we know very well here living in Colorado. Zinc-air batteries need oxygen to operate. So less oxygen can result in a shorter battery life.
Humidity – Living in a dry climate, which is typically the case here in Colorado, or furnace use during the winter months can cause hearing aid batteries to dry out more quickly. High amounts of humidity will cause the hearing aid batteries to absorb moisture, which can shorten battery life and cause leakage.
Using what we have already reviewed about hearing aid batteries, you should have a head start on proper zinc-air battery storage suggestions. The ideal place to store hearing aid batteries is in a room temperature, dry location. Storage in the bathroom, refrigerator, and car are less than ideal. Hearing aid batteries should be kept in their original package or in a special battery caddy. Metal objects like coins and keys may short circuit the battery and reduce the lifespan. Do not store batteries in reach of children or pets, they can cause serious injury. If swallowed or inhaled, contact the National Battery Ingestion Hotline immediately (1-800-222-1222).
All hearing aids batteries sold now must be mercury free, which means they are environmentally safe to dispose of in the garbage. Never dispose of batteries in a fire, doing so may cause them to rupture, releasing internal ingredients.
For other hearing aid battery topics, check out the battery section of our website. You can also contact one of the Audiologists at Mile High Hearing, we are always happy to answer questions and educate patients.