Mercury-free hearing aid batteries have some problems

July 2010

Editor: I'm all in favor of efforts to preserve our environment, but should we accept dysfunctional hearing aids as the price? It's not that cut and dried, but this is an issue we may have to deal with before long. Thanks to the folks at hear-it.org for this story. You may want to brew a fresh pot and visit their site at http://www.hear-it.org

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New mercury-free batteries can not only benefit the environment but also give hearing aid users a clearer conscience. The new types of batteries can cause problems for the hearing aids users. Both the battery manufacturers and the hearing aid manufacturers work hard to solve these temporary problems.

We are all concerned about preserving our environment. Removing mercury from Zinc-Air batteries is a natural consequence of this concern. It is now possible to produce mercury-free Zinc-Air batteries of a high quality and in certain market areas all hearing aid batteries will soon be required to be mercury-free. The major battery manufacturers have therefore voluntary agreed to achieve this goal by the end of June 2011.

The battery industry has already made remarkable progress technologically, but there can still be problems when using the new mercury-free type of batteries in hearing aids. Hearing aid users have reported cut-outs, shorter battery life than expected as well as battery low warning tones even when batteries are quite new.

Lower capacity

The problems are not caused by any fault in the hearing aids as such, but are caused by a low battery voltage that in many cases results from the mercury-free battery technology. The user will often experience lower battery capacity. Such problems occur in particular in hearing aids having high current draw from the battery, such as power aids and hearing aids with wireless connectivity. The incidence of these problems has increased significantly after the introduction of mercury-free batteries.

If you consistently experience the problems described above, it would be advisable to try a different type of battery. Your hearing aid supplier may be able to advise you on which types cause the least problems.

Power aids and wireless solutions

The hearing aid manufacturers are well aware of the challenges which the new type of battery faces and will work towards products that can function well on lower voltages in order to minimize battery related problems. Many hearing aids on the market such as power aids and hearing aids with wireless connectivity are designed to work with the voltage levels provided by batteries relying on mercury. These hearing aids require batteries with performance comparable to good batteries using mercury-based battery technology.