AudiologyOnline Phone: 800-753-2160


Extending Hearing Aid Battery Life

Denis Carpenter

May 26, 2003

Share:

Question

What can I do to make my hearing aid battery last as long as possible?

Answer

Zinc air hearing aid batteries use oxygen to produce energy to run the hearing aid. Since zinc air batteries contain tiny air holes, certain environmental factors like water vapor can affect battery life. Normally, the concentration of zinc air eloectrolyte will cause the cell to have an internal humidity of 50-60 percent. At lower humidity levels, the cell will lose water, concentrating the electrolyte. Eventually, at this lower humidity level, the cell will lose its effectiveness. When the ambient air has a higher humidity level, the cell takes up water, which dilutes the electrolyte and floods the cathode. Again, the battery cannot function.

This is why the best way to make your hearing aid battery last longer is to minimize water transfer. All zinc air cells have a tab that covers the air holes to insure freshness prior to use. Once the tab is removed, water transfer begins. You can try re-tabbing the cell when the hearing aid is not being used. The effect of re-tabbing will vary based on the ambient environment the battery is subjected to. Re-tabbing will have little effect if your typical battery service life is less than five days, or if the ambient humidity conditions are around 50 percent. Re-tabbing could be very beneficial if your typical service life is longer than 10 days, or if the ambient humidity conditions are either to low (northern climate winters) or too high (non air-conditioned summers).


Denis Carpenter
Rayovac Corporation
Zinc Aid Technical Manager
BS-Chemistry UW-Lacrosse
25 years experience in zinc air research and development


Click here to visit the Rayovac website.


Denis Carpenter

Zinc Air Technical Manager, Rayovac, Madison, Wisconsin.