Question
Can a dry-aid kit be used successfully to extend the life of zinc-air batteries? What about other types of batteries: such as NiCad, mercury, carbon, etc.?
Answer
We have tested zinc-air batteries with various hearing aid drying kits. We have found that generally, drying is harmful to zinc-air batteries. This is not surprising since exposure to dry air tends to dry up the electrolyte, leading to shorter service life.
While dry-aid kits may be good for hearing aids, they are not good for zinc-air batteries. It is best for the zinc-air battery to be removed from the hearing aid prior to using the dry-aid kit.
Now on to your question -- Since other battery types (NiCad, etc.) are
sealed (do not have vent holes for air access), it is very unlikely that
putting them into a drying kit would affect their performance one way or the
other.
BIO:
Randy Rea has a B.S. in Chemistry from Lynchburg College and a Ph.D. in Chemistry from Cornell University. He has been in the business of developing batteries for consumer applications for over 25years. For the last five years, he has been Director of Zinc-air Technology at Rayovac. In this capacity, he directs all aspects of hearing aid battery development.