Power One zinc air batteries , Power One is the most advanced hearing aid battery manufactured in Germany. Power One is Perfect for hearing aids because of the air electrode (1.45V system). It is Corrosion free due to a stainless steel case. With the mercury-free hearing aid batteries wireless approved, power one has developed efficient batteries that especially meet these requirements of the new hearing aid generation. Why do zinc air hearing aid batteries have a tab? Hearing aid batteries utilize air as an energy source. The tab seals the battery’s air holes. Once the tab is removed, the hearing aid battery is activated.