Bests & Worsts Reviews from Amazon

These batteries always, always work! If you come across one that doesn't work, don't throw it away. There's something weird about hearing-aid batteries your audiologist might have failed to mention: They don't work at all if you strip off the brown tab and slam the battery door on the hearing aid closed really fast. Instead, you have to let them breathe for a minute, literally. (This is a property of all brands, not just Duracell.) Explantion (with thanks to Dasher for his clarification): If you look at the fine print on these cells, you'll find the words, "Zinc Air," indicating they are a special variety of of alkaline batteries that use oxygen as their cathode. Put these cells under strong magnification and you'll see three tiny holes on the cell's surface. When you strip off the brown tab, air—specifically, oxygen—is given entry. If you slam the door too fast, the oxygen doesn't have time to penetrate. Open the door, wait for a minute, and close it again. The battery will come to life. (If you wait a long time to open the door, the battery can fail.)