Been using hearing aids for several weeks that run on size 312 zinc-air
button batteries. They last about a week then go dead along a very sharp
discharge curve.

I measured some used ones in a battery tester and their voltage has
returned to normal- around 1.45v. Not sure how long they'd last if tried
them back in the hearing aids- or it's a good idea to put them in there.

--
There are two theories to arguing with a woman. Neither works.