Granada Batteries is a leading stockist of battery and charging solutions including specialty items like this selection of hearing aid batteries. We stock high quality products from Rayovac and other top brands. Buy your hearing aid batteries online today.Removing the sticky tab activates the hearing aid battery as air enters through the 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. Voltage is another thing that should be explained. Although the package of most batteries will state 1.45 volts, the fact of the matter is that 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.