Quote Originally Posted by E. von Hoegh View Post
Hearing aid cells. Block off 3 of the 4 holes, it will last a year or more. You'll have to make a holder for them, I used some plastic tube and sheet copper. You can also recalibrate the finder to use silver oxide 625s (they are available).
I've read about your technique for blocking off holes, and it makes sense for longevity's sake. But what about capacity? Seems like by the time you took repeated meter readings in quick succession, that the air intake and chemical reaction would not be able to keep up, and voltage would drop. Further, are you drilling air holes in the battery cover?