Batteries in My Aids

I’m using the batteries that came in the bag with my hearing aids.

I think I remember reading somewhere that #10 HA batteries average about 5.6 days.

Micro Tech Focus 40 Hearing Aid
Microtech Premium #10 battery (not sure who makes them, print is too small)

I heard the low battery beep in my left hearing aid at the end of the 5th day. I replaced both batteries.

As soon as I replaced them it became obvious to me that the hearing aids were louder.

I did the same thing again at the end of the 4th day this time before I heard a beep. The last two ours I had the aids in I could tell they were low. As soon as I changed the aids were louder.

That’s my story anyway.
Does this sound right to you guys?

That is not what I experience. I think my HA’s pull more as the batteries get weaker, so I don’t notice a difference with a fresh battery. Mine used to last three weeks, now they last ten days, with new audiogram. Once the beep starts, I have about 90 min of power left, before they go dead.

I don’t even know if what I’m describing is possible but it sounds like the hearing aids are getting softer because the batteries are low. I guess I’m asking if this is possible or if I’m imagining it.

We will probably have to wit until tomorrow for an authoritative answer, but I know they used to be like that, but more recent ones had a correction for nearly drained batteries built in. Mine must. IDK, maybe that is not working on yours, which are substantially newer than mine.

Hearing aid batteries are supposed to function until a cut-off level is reached, after which the hearing aids will signal that the battery is low. However, I’ve had numerous patients tell me their aids act funny or make strange sounds just before their batteries go out, so I wouldn’t discount the possibility that this is what’s happening with yours.

I experience sounds to not be as good and I use #675 batteries. My friend experiences it as well with #13 batteries so I think it’s pretty normal!

Sho - this exactly happens to me as well with my #10s - can always tell the day my battery will beep and go dead. And as soon as I put in new batteries, there is improvement to sound.

if you avg x numbers of days from your batteries why not simply change them the morning they are scheduled to go dead? I would like clock work get 7.5 days out of size 312 batteries in my rextons so I just got in the habit of replacing them every Sunday morning.

I have size 13 and although it doesn’t happen every time because I change them at 9 days (if I look at the calender) but it does happen occasionally that the sound is not as sharp at the end of battery life.

I probably don’t notice mine getting a little less sharp toward the end of the battery life, but I do notice that they are a little louder with a fresh set in…so they are probably a little lower at the time the battery alarm goes off.

This effect is probably in the last 10 % of the battery life or so…Zn air batteries are designed such that they produce full power until they (almost) die.

I"d say there is nothing to worry about and just change your batts when you notice the change…

I have been using Energizer 312 batteries from Sam’s Club. I notice my aids are just slightly louder after replacing the batteries. Today I found a manual for the battery that shows the discharge curve.

On that curve, the voltage is just under 1.4 volts at the start, then after about 5% discharge, the voltage is just under 1.3 volts until over 90%. So I think I hear just slightly louder at first just after replacement, then I don’t notice it.

I can’t post links, but here is an incomplete link:

data.energizer dotcom /PDFs/zincair_appman.pdf

I read that manual more and learned something I did not know: It says to wait 30 seconds after removing the tab before using.

Here is a paragraph for the manual:


The key to miniature zinc air battery shelf life is the tab seal. This seal should not be removed until the battery is put into service. Miniature zinc air batteries stored at room temperature with the tabs left in place and subjected to typical hearing aid service tests show 95% of initial service after one year and 90% after two years. Accelerated testing indicates that room temperature service maintenance at three years should exceed 85%.
To activate air cell battery remove tab. For maximum power, allow the battery to be aired for 30 seconds before placing in device.
The activated (tab off) air cell batteries have an expected fresh capacity maintenance, depending on cell size, of 50% after 3-12 weeks at 20oC (68oF). Beyond 20 weeks, at 20oC (68oF), fresh capacity maintenance drops to 0-10%. It is therefore very important to keep the tab seal in place until usage.


Last time I looked at the situation, PowerOne had the best discharge curve (nearly flat) as well as giving out 1.45v. The cheap Chinese junk tends to have poor discharge curves, but even non-Chinese batteries can give off only 1.4v. Its usually indicated on the back of the pack what the power level is.

An HA battery dealer here in Australia sells a mystery pack where you get a packet of every brand, both well known and no-name Chinese, so I bought one. (size 10)

I carefully set up a log and recorded the results over about 4 months, and the result was surprising. There was very little difference! I found that wearing my CICs 14 hours/day, I got between 8~9 days regardless of brand, and as they cost me only 40cents per week per ear, I decided to hell with the expense, I’m going to change them first thing monday morning, avoiding them going weak or flat in the middle of my work day. Trying to stretch out that extra 5cents by going until they were flat was just not worth the hassle.

There are plenty of ebay and non-ebay dealers selling packs of 60 batteries for around $25, which means approx $0.40 each, and out of the mystery pack I chose the cheapest Chinese brand as my regular battery, and have never regretted it.

you can get 60 #10’s from this site’s owner for $19.99.

my 312 batteries last two days in my Phonak BI CROS (I love the BI CROS)
wonder if anyone gets better time than that?
I had my audiologist give me a bigger transmitter that takes 13s but I don’t want to give up the smaller aid that takes the 312
The audiologist said the constant streaming eats the batteries
Is there a cheapest place to buy batteries? I look for bogo offers around here

A friend of mine gets 2-2 1/2 days out of his BI CROS with 312’s, so you’re in the ballpark. He got his HA’s from the VA so batteries aren’t a problem since they are free. 13’s are only going to get you a couple more days. For cheap batteries Costco gives you 40 for about $10.