Question
I always use a new battery when fitting a patient with new hearing aids. But why is it that some batteries will work as soon as I take the sticky tab off, but others are bad batteries and do not power the hearing aid right off the bat?
Answer
As the name implies, zinc-air technology uses oxygen from the atmosphere as an active ingredient. This technology is used almost exclusively in hearing aid battery applications. Zinc-air batteries are best used soon and consistently after activation, because the battery begins to discharge as soon as that tab is removed. Removing the sticky tab activates the battery as air enters through the small holes. After the tab is removed, the battery literally requires a moment to “catch its breath.” As air starts to enter the battery, it becomes able to be activated. We always recommend that you let the battery sit for a full minute before you insert it into the device and shut the door. That is important because it allows the voltage in the battery to rise and ensure that you will not have start-up problems with the hearing aid, as you mentioned.
Although the package of most batteries will state 1.45 volts, batteries that are still tabbed on the shelf will measure anywhere from 1.1 to 1.3 volts if you were to test them with a volt meter. After you take the tab off, the voltage will rise enough to power a hearing aid within one minute, but the entire cell could take as long as 24 hours to rise to the maximum 1.45 volts. Un-tabbed voltage after a maximum of one day is 1.45 volts. The important thing to know is that the hearing aid does not require 1.45 volts to operate.
Furthermore, always use a fresh hearing aid battery when you are programming the instrument. The programming cycle of many of the hearing instruments on the market today can put high demands on the battery and even use up the entire battery during programming. Therefore, make sure that you do put in a fresh battery when you are done programming.
To avoid seemingly “bad battery” situations during a fitting, un-tab the battery, wait a full minute for it to air up, and then insert the battery into the device.
This Ask the Expert was taken from the webinar presented by Kevin Kouba, MBA and Ann Rule, MBA. To see the complete recorded course, go here.
