Does a hearing aid battery stop working after getting wet / being dropped in water?


I was reinstalling the one day old Costco 312 batteries in my Kirkland Sig 5 hearing aids. I dropped one and it went immediately down the drain to the water pool in the trap. It was a bathroom sink so I was able to disassemble the trap without any tools, I estimate the battery was under water for about 5 minutes. I dried it and installed and all seemed well. But within a few minutes I got the low battery signal.

I let the battery air dry the rest of the day but it soon dies when installed in a hearing aid. Is this just a coincidence or does submersion in water destroy this type (zinc air) battery?


way more effort then I would waste trying to save a battery.

— Updated —

way more effort then I would waste trying to save a battery.


I have read that high humidity or water can destroy zinc air batteries. I don’t know the specific chemistry of this phenomena. I think your battery is effectively dead but it would be an interesting experiment for you to dry it and see if it has a long remaining life. Good thing it wasn’t your aid in a sink filled with water.


Thanks, I am much curious as concerned about cost. Taking the plumbing trap apart in fact didn’t take more than 5 minutes, of course I have to put it back together.

I have reinstalled the drown battery again about 2 hours ago and it is working fine so far. The battery has three very small (big compared to a oxygen molecule but not to a collection of water molecules - but I suppose a few molecules could squeeze through those small holes… and work their way back out during drying. I’ll keep using this battery and see if it comes anywhere close to the 6 day life my first Costco batteries lasted. The fitter threw in two cards, 20 cells, in the box when I had the HAs fitted. I’ll see him again on the 11th August. I really have no complaints, but there may still be some improvements in the “program” he can make to make the HAs even better.

As for batteries, I was surprised and very happy to learn how long those little energy cells last and how little they cost. Hearing aid batteries don’t cost enough to earn even a mention in the budget.


The reason why it partially died is that you shorted it completely and starved the oxygen feed. Shorting a battery like this can cause it to overheat (but not in water). The oxygen feed is needed to let the Zinc ‘burn’.

Excess humidity or moisture at the battery drawer can have similar effects.


Interesting, the water submersion on the one hand shorted (by what ions in the water) and on the other deprived of oxygen to discharge.

Now a bit over 24 hours later the subject battery is still working and was used since about 11 am this morning, 12 hours ago.


Just for the record (one data set) my right HA battery is signalling for replacement. The left battery which took the bath has not yet dropped below the voltage threshold for good battery. I have been sticking each on a piece of scotch tape each night to seal (at least partly) air holes As this is the 7th day, the tape on the holes appears to add one day to the battery life. Again, just one test run, only an indicator. More important, the battery that was submersed in water for a few minutes seems not to have been damaged in any way.


Do you have one aid producing more power than the other? Do you think that this variable could explain the power variance you are experiencing?


Interesting, yes my right ear is worse than my left, both need help.

I replaced the left battery yesterday, 9 days or so. I’ll watch to see if there is a pattern to the replacement, right always going first.

My main interest in starting this thread was the affect on a battery by being submerged in water for a short period (minutes, not hours). My one test says the water did not damage the battery.

I’m “okay” with batteries lasting 6 days, my first set… but I am not sealing the back of the batteries when I remove the HAs at night - bedtime. I am using just clear plastic (scotch) tape. There may be a risk of plugging up the air holes, but so far no sign of that, just a longer use life.


Ok. I am now similar type situation. Last week, My battery
got wet. Although, it’s still working fine, but I am feeling that it has lost
his 100% efficiency. How can I test that my battery efficiency is not
decreased? However, here is my new battery Best 18650 flashlight review 2018(December) . I have decided to buy new 18650 battery for this.


They are cheap enough that I’d just replace them. I accidentally left a battery in my former aids and oxidation to the contacts resulted. The moisture could make that a possibility and the battery is so cheap that I’d want to replace it to avoid any possible issues.


Help me understand the logic of not throwing the wet battery away? The risk to hearing aids far outweighs the reward of RE-using a wet 20 cent ($9.99 for 50 at Costco)battery???


Batteries are cheap enough. I would of just chucked the wet battery away and put a new battery in my HA. I wouldn’t of risked it.