Why wait to insert new batteries in their receptacles?

I’ve always been impatient. So, I interrupt my wife; I send emails without proofreading them; I fasten my seatbelt while backing out of the garage.

AND, I pull the stickers off new 312s and put them in my Phonak hearing aids immediately rather than wait for 10 seconds, or 30 seconds, or 2 minutes.

What’s the reason we’re advised not to do that, and how long, really, must we wait? Can we wait with the batteries nestled in the HAs with the battery receptacles open, or must they sit uncovered on a non-conducting surface where they might be discovered by my cat while I wash my glasses?


Waiting allows the chemical reaction to proceed long enough to raise the voltage. I’m not an engineer, but my understanding is that if one doesn’t wait to let the voltage rise and use immediately that the batteries won’t last as long. I haven’t read anything convincing for waiting more than a minute and waiting with hearing aid doors open should be fine. That said, I tend to wait several minutes and anecdotally, batteries seem to last a little longer.


One minute is enough to get the chemical reaction going. But having said that, I rarely wait that long and I can’t say I notice that the battery life is any less.

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I never wait after peeling the label and cant say that I’ve noticed any less battery life. I get at least 5 sometimes as much as 7 days between battery changes. My data logging says I use my HA’s an average of 14.7 hours a day, all of my mobile calls, music etc. are streamed, and that’s with at least a couple of hours a day of TV streaming to them as well.

I’ve noticed some say wait a minute, others as much as 5-7 minutes. It may have come from a time when the batteries actually needed time to start up, I doubt with todays technology they still need this time.


I was told to wait 1 minute to 2 minutes just because of the chemical composition of the batteries. I did have a hearing aid battery tester back in the day and tested it out by placing it on the tester. It’s about 70-80% with the tab still on. Once you peel the tab, it goes to 90% and after 1-2 minutes or a little before, it goes to near full capacity.

When I change my hearing aid batteries, I’ll pull out my multimeter and take a look for you and report back!


I believe I should wait a minute+ after all I’ve read. But I don’t. I assume I’m getting 10% less battery life due to this. For a total annual cost of under $5. Worth it!

I’ve measured the voltage and you can see a fresh battery increasing it’s level over about a minute. Having said that, I don’t always wait either and they always seem to work. It’s a mystery really. At the low voltage you’d expect the aids to either not start, or give a low battery warning. Maybe the extra current draw causes the voltage to rise quickly??

1 have never waited even a second to install the new battery in my aids.I did, however, in a brief test wait 5 minutes or so, that making no difference in the 5 to 6 day life of batteries. I do much listening to music with headphones (for bass) leaving my aids active (for treble). My hearing loss is severe and my aids are put to the test. IMHO waiting is completely unnecessary. The battery (ies) are open to oxygen and moisture immediately upon removing the seals. Inserting into the aids doesn’t impinge in this action.


My experience has been that waiting doesn’t matter. By the time I peel off the tape, put the battery in the door and shut the door, the chemical reaction has occurred and I’m good to go. I use rayovac. Maybe other brands are slower to react.

Thanks to all who’ve weighed in. My sense is the consensus is "why not wait a minute or two if you have a few other 30 second tasks you can do in the moment, but that it’s probably not worth any more concern than we’ve already expended on the topic.

Thanks again,
Jim Robertson

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Isn’t that a given, if you never try the other option? :slight_smile:


I’ve got no horse in this race, but whether you need to let the battery ‘charge’ is likely to be the availability of air, which is usually a function of how gunked-up your battery drawer is.

CIC and ITE, it won’t matter, due to the volume of air inside the shell.

RIC and BTE, ensure that the closing faces aren’t greased with earwax or covered in moisture. If there’s a goretex filter into the compartment, keep it clean or remove it completely.

I think you can pretty well guarantee that RIC and BTE HAs won’t have ear wax around the battery housing! Might have some hair grease though of course.

You’d be surprised, skin oils, wax, sweat, skiing fragments, cement, soil, clay, plaster dust, artex, hairspray, sunscreen, makeup, food fragments, dried drinks of all sorts, seawater, poolwater and other random gunk.

Some doors are really gummy when you open them. It mostly dissolves with alcohol and light agitation.

Old Phonaks used to have a goretex filter under the aid to allow air into the battery compartment, worked great until you had a the slightest bead of sweat wick in there.

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Sorry if I wasn’t clear, I meant to say that I have not noticed any difference in waiting after peeling the tab vs peeling the tab and using the battery straight away.

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Hi shelldrake: can I ask how you perform data logging?

Sure, I was referring to the average hours per day that the Target software software reports.

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I put mine in the battery slot then I peel the sticker off…
Then I’ll pause a bit before closing the door. How long I pause depends on if I’m in a hurry. Usually about a minute…but I’m not counting.

I did an anecdotal experiment for a while, closing the door right away. My theory being that there’s plenty of air inside the battery compartment for the reaction to keep going. I didn’t note any sort of significant degradation in life span but there might have been an extremely slight difference…
My theory after that was that even though there’s air in the compartment, maybe that first draw of energy happens before the voltage is fully up if you close them right away and that might in theory shorten their capacity a smidge…
so I figure why not pause if I can? it’s only 30 seconds or a minute or two and I usually need to brush teeth or other things anyway…and my case is right there to put them in for safe keeping

I have to wait at least a minute - if I put fresh batteries into my KS9 aids they don’t work - if I don’t leave them long enough then I get the low battery warning until I open them up for a little longer. Once they are active, I get the normal 3 or 4 days from the Costco 312s with regular streaming. As no-one else mentions this, might there be something wrong with my aids?

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3-4 days sounds about right since that’s how much my KS9’s last for. The low battery beep is because the batteries have not reached their optimal voltage yet. In some cases other people may have different things happen, but there are plenty of variables to take into account for sure.

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