Battery life

I have 2 Sterkey Zon hearing aids the battery life is about 25 hours of use or less is this normal ? I was told when I purchased them battery life would be 80 to 100 hours I have had them sent in for repair several times and been told that there is no problem with them

I assume you mean Starkey Zon hearing aids. They come in 2 power levels of receivers (speakers), 40 gain and 50 gain.

According to page 4 of the Starkey specifications here [PDF], you should be able to get 6 - 8 days with the 50 gain and 8 - 9 days with the 40 gain, based on 16 hour days when using zinc air batteries.

I find that the brand of batteries can affect battery life too. I have had good results with Ray-O-Vac batteries.

This comes up a lot.
For $25 or so you can buy a multimeter and a few resistors at Radio Shack and run your own battery capacity checks, and with some difficulty you can check the current draw of your aid. You will not be looking for subtle differences in this case.

In these kinds of situations I’d ask your aid supplier “How short of a battery life would you consider flat out abnormal?” before you tell them what life you are getting.

Your house’s energy consumption is measured with an AC watthour meter - ideally, if you had a DC milliwatthour meter you could check your aid pretty thoroughly.
It could be built for approx. $50 in parts (with voltage-to-frequency convertors, opamps and counter ICs) but nobody seems to sell such a device so I assume the hearing aid companies have their own custom-built test setups for this.

Checking the current draw would probably not help much since zinc air batteries are really like fuel cells. Once the tab is pulled, allowing air to get into the battery, a chemical reaction starts that cannot easily be stopped. This reaction runs, producing electricity, until the battery is depleted.

For a given environment (same temperature & humidity), the battery lasts about the same length of time whether or not there is a current drain on it. You can oull the tab and not use the battery and it will still deplete in the same length of time.

Pat,
Are you wearing the HA everyday and only getting 25 hours out of the batteries or are you wearing them only occasionally and only getting 25 hours out of the batteries. If you are wearing them everyday and only getting 25 hours out of them I would say something is wrong with the HA. However, if you are wearing them only at meetings or when you think you are going to need them and 6-9 days go by with the 25 hours of battery life, then I would say the batteries and the HA are ok.

Referring to the posted datasheet, here’s some calcs using a spreadsheet

zinc air 312
130 =mAh capacity

6 =how many days
16 =how many hrs/day
96 = total hrs

current draw
to get these many hours is

1.354166667 =mA = mAh/hrs
rounded to two significant figures this is 1.4 mA.

for

25 =hrs
you’d need to draw
5.2 =mA

And mAh = hrs x mA and hrs = mAh/mA

There are several unknowns:
what mAh usage can the typical customer (50th percentile) and the worst case customer (95% percentile) expect from the aid?
how much does self-discharge contribute to this? Trying a different cell technology may help answer this question.
what mAh rating does the cell typically provide at the current draw of the aid? Cell capacity varies somewhat with discharge rate.

Or, just get some better batteries. 312 should last a week unless they are partially discharged. Only exceptions to this would be a mega power receiver or use as a CROS mic.

Given the premises, the customer’s results should not follow. It’s a non sequitur of the “if p, then q” variety.

Pinning down the HA and battery providers with very narrow questions should resolve this and put them on notice that this user is more informed than most.

If you can get past the marketing people and e-mail an engineer on the factory floor some answers should hopefully follow. Sometimes e-mailing your state’s attorney helps with this, but if he starts talking about “mediation” you’ve wasted your time.

WTF?

They are batteries, try a packet from each manufacturer and see which works best.

I think ?tahW likes to overanalyze everything to “prove” their knowledge.

I agree. Try different manufacturers. I usually got 4 days using size 10 batteries in CIC or 312 batteries in ITC aids. I now get about 8 days with Ray-o-vac size 13 batteries in my RIC aids.

The OP asked for help, I’m giving it.

You can also model the zinc air self discharge as a constant current drain and, using a weighted average, again check whether the HA or the batt. manuf. or both are making false statements. Right now, each can blame the other.

If my IQ, knowledge, skills, abilities or life experience bothers you, I can tell you at this point that, among other things, I do not qualify for Mensa.

I will leave this forum
when my “net gain” therefrom crosses through zero
or
when this forum’s net gain from me crosses through zero
or
when I get banned,
whichever comes first.

To some extent each OP and forum member has some influence as to when this point will arrive.

Well said. Not only that, different packs from the same manufacturer may vary. Tabs that are not sealed well can be a major culprit.

this can not be answered until the OP explains what he means by 25 hours of use? as stated earlier if he’s talking 25 hours of use over 7 or 8 days it is what it is. 312 batteries go 7 or 8 days depending on how high the aid is set, streaming hours, etc… if as most would think of 25 hours use over 2+ days then he does have a problem. We need to know over how many days his 25 hours of use is spread.

Now wait until the end before you get all upset about this post…I promise it’s worth it.

25 hours is 25 hours regardless of whether it’s spread over 2 days or 8 days.

REGARDLESS, 25 hours is abysmal for a 312 battery, if it was a 10A and the person had a pretty significant loss, it might be acceptable but IMHO, not for a 312 or larger (definitely not larger) the ONE exception being the Phonak CROS transmitter. It has a 312 and you’ll have to change it every other day - at most every third day. Here’s where it gets good so hold onto your britches, I agree with Sweetcheeks here…this person has a problem. Something is pulling the battery and it should be looked into.

if he means he wear the aids for 25 hours over 7 or 8 days he really has no problem. as a 312 battery once opened is eating itself. it would also be interested in how he is not wearing the aids. battery out? aids on mute. if he means he is only getting 2 days from a 312 battery then there is a problem assuming he is using fresh batteries. as is during those 25 hours if it is mostly streaming music or bt phone would also impact how long they should last.

Well, I just came from my dispenser and the computer stated that I was getting about 85 hours per battery wearing them 15 - 16 hours per day. I use 312 and am pleased that I get 5 to 6 days of use per battery.

JMHO

I actually agree with you too. The “battery” will eventually consume its fuel. Wait a minute… where am I?

If a given HA has to be cranked up a lot more to service someone w. bad numbers, wouldn’t they wear out sooner than the same HA programmed for someone w. moderate numbers?

   Could you extend the life of a battery each nite if you simply put scotch tape over it to keep air from getting in?    A couple times I've pulled the tab off a battery only to discover the old battery was good (just needed to replace the wax guard).  A few weeks later when I remembered I had a "used" battery - pulled off the tape and it worked like new.

…mike

The more the HA has to work the faster it will go though the batteries. However, as long as the batteries are getting air they will be expending their energy, it might be worth a try to cover the holes each night and see how much longer the batteries last.

Covering the holes won’t result in any noticeable change in life of the battery. Once the oxygen gets in the chemical process starts that results in the current, while it’s true that a battery needs oxygen to work, putting tape over the holes doesn’t shut off the chemical process that has already started.