I am extremely skeptical about the 1 Minute and 5 Minutes rules simply because I looked closely at my hearing aids and it is very clear that they do not have an airtight seal on them. I have not seen any battery powered aid that says it has an airtight seal. And even if it did there would still be residual air inside once the seal is closed. Air is inside the aid at all times so air has to be getting absorbed into the zinc mixture. Oxygen is absorbed on the molecular level so that any battery having the tab removed will freely absorb oxygen from the air. also the 1.4 - 1.45 volts is standard for 312 batteries but many sites including Sony and Rayovac mention that it can and does vary based on conditions. I would expect conditions such as moisture content (humidity) to be an important factor on the voltages produced.
Funny! My uncle worked at 3M in MN his entire life! That is a company with a looooOOOooong history!
Yes, I totally get you on the “adhesive transfer” issue. That’s why I started rubbing the tops of my stickered batteries with a Q-tip dipped in rubbing alcohol after removing the tabs. I also felt like the cleaner the surface, the faster the O2 holes could get the battery ready to go.
@don2
as a has-been pro photographer with equipment that had to work always…I use a coarse eraser. I prefer white Staedtler erasers. Failing that, any eraser on a pencil will do and the size is better
As an engineer who was trained on a drafting board, I’ve always had a pencil size Staedtler eraser. Works well.
Thanks for the reply. I have used erasers that way for many years also. Unfortunately they wont fit into my ks9’s. Maybe somebody should make an eraser in the shape of an eraser. lol
I actually whittle an eraser down to size if I need to…
and I’m careful there’s no eraser dust in the hearing aid battery case.
The only time I’ve had a hearing aid fail because of adhesive on contacts the eraser fixed it. Back in drafting days I carried a mechanical pencil that had a very small eraser under the top. That worked too.
Now I have rechargeable bateries in my Paradise P90R’s. It’s easy to clean the contacts. However, the batteries don’t last long enough.
DAveL
Toronto
Metering the voltage of the 1.4v cell sitting on your table is probably not very meaningful because almost all precision battery powered circuits are designed and regulated to operate at a lower voltage. The op was testing the cell under a no load condition, but as soon as the hearing aid is turned on, the cell voltage will drop. It would be very difficult to measure the operating cell voltage unless you knew the design current load and had a variable load for your bench tests.
Also as the hearing aid gain is increased the current draw will increase too. Those that have noticed a reduction in sound quality as the cell is reaching the end of life, are at the point where the cell voltage under load is fluctuating at or below the designed regulated voltage which is causing the distortion. For a voltage regulator circuit to work properly, the voltage of the 1.4v cell must be somewhat above the desired operating voltage. As the cell voltage under load approaches the regulated voltage the audio sound peaks will drive the cell voltage down to the point where the regulator circuit fails, thus distortion.
Wonderful explanation!
Is there a meter that will test batteries simulating load?
DaveL
Toronto
some folks seem to need a hobby…
Grandpa what did you do today? I got my voltage meter out and was checking my hearing batteries…
I open a pair of batteries, then I remove the batteries from my aids. I check the filters, run the wire through the vent holes, wipe everything down, install fresh batteries and good for another 4 days.
rubbing alcohol works! It will dissolve solvent based adhesives such as those that 3M (used to?) make. I found that just letting the bare battery sit uncovered prevented my problem. My first audiologist emphasized I needed to do that. She said it “energized” the battery. Whatever the reason, it works.
We used to refer to RM19. It was a good cleaner. Whatever it was, someone used to take it home in quantities somehow and did dry cleaning in his basement. Until he did too much. It was flammable.
I did a search, but couldn’t find any consumer priced testers that stated that they will test a hearing aid battery under a load. There are laboratory grade instruments available, but they will cost more than your hearing aids. I would stay away from the simple analog meters because the meter itself will become an un measured load.
In my case, this discussion has been of academic interest only, because when wearing my Phonak Bolero V70 aids, I just pull the tabs off the new batteries, remove the old batteries, insert the new ones, place the aids in my ears, and turn them on. I don’t wait for them to get to full voltage, and I consistency average 6 days per battery change.
And as another person posted; yes we all need a hobby, which is one of the reasons I acquired the software to program my own hearing aids.
Not the same. A car has an alternator that charges the battery and also powers the car once the engine is started.
Once a car engine is running, you can disconnect the battery and the engine will run fine. A low battery in a car may affect the electrical system some, and of course, not start well, but not really the engine or tranny because the alternator takes over once the engine is started.
I downloaded the technical data sheet for a 312 Ray-O-Vac battery, and it states 1 minute to activate a cell after pulling the tab. Also a sealed cell will loose 10% of it’s capacity per year in storage.
This is from the manufacturer, so I would disregard any of the stuff being spread around by others.
Years ago when I had OPN aids with 312 zinc-air batteries, I looked at battery manufacturer’s documentation and found wait times for activation between 1 and 5 minutes. More recently, the times have changed, possibly with the changes to the chemistry when mercury was removed.
Of interest is another Ray-O-Vac on-line document about performance in non-standard conditions:
https://rayovac.eu/how-humidity-temperature-and-altitudes-can-affect-hearing-aid-battery-life/
my mistake mr. smithster you are correct, but I did experience low voltage symptoms which had to be a bad alternator, not a bad battery. -op
Just for fun I tried exposing size 13 Rayovac batteries for 24 hours and suprisingly got 18 hours better life, ie from 6 to 7 days.
They power Naida M90 SP and are worn for 11 and 3/4 hours.