Rechargeable versus battery hearing aids

You make a very important point in your post. EVs use very advanced battery management systems to assure balanced charging and discharging,temperature cutoffs to protect the batteries, and usually a reserve set of batteries that can be brought “online”should one pack no longer perform to specs. No HA will have anything like that. There’s barely any room in there to begin with, these are tiny Lipo batteries of some chemical configuration (from clsssic to the lower voltage LiFe designs which I’m not sure are even available in the right form factors). The other big difference, changing a rechargeable battery in a HA is way easier (even if it needs a factory visit) than changing out EV battery sets.

And yes, those electric motors give incredible speed and generate excellent torque. The new Tesla S plaid edition (pretty sure it’s called plaid) is now the fastest production car available capable of 0-60 in just under 2 seconds. The quarter mile was also impressive 9.3 seconds. Top speed is 200 mph. Now those are amazing specs. No, it’s not cheap, but if you’re looking for say a Mercedes S class and AMG versions, the Tesla is a very competitive car looking at performance (oh yeah it measured at 1,100 hp).

@eskie227 said:

There’s barely any room in there to begin with

I think size is a constraint induced by the user of the device not wanting to reveal wearing HA’s and by marketing - HA’s were originally larger than today and it wouldn’t take much of an improvement in power density - for EV’s I understand the goal is to achieve ideally a 10-fold increase in power density with a newer, battery battery chemistry (which might not be Li-ion). I can already essentially practice battery management of range with ReSounds - the battery life of those rechargeables is significantly better than Phonak’s because of Phonak staying with Classic Bluetooth. Going from 80% to 20% with ReSound gives me 18-hours of usable battery life (6 hours per 20% charge) and one can stream a lot with very little dent in battery life, unlike streaming with Phonak’s “solution.”

So saying it can’t happen is just plain wrong - ReSound already belies what you’ve written. Phonak would have to upgrade battery size or switch to BLE, though.

Edit_Update: I just threw out the word “marketing” but “economics” might have been a better word to try to summarize EV batteries vs. hearing aid rechargeable batteries. An EV battery is still so expensive, even though greatly reduced in price in recent years, still about $125 per kWh. So an F-150 Lightning battery is $125/kWh x 150 kWh = ~$18,750. No one would buy an EV if the battery was only good for 5 years. So EV makers have to preach the gospel of how to get the most life out of your EV car battery and induce EV buyers to join the cult of battery lifespan preservation. A rechargeable HA battery is so small, its replacement is nowhere near as painful, and not worrying too much if the battery ages relatively rapidly fits nicely with the tendency of many HA wearers to get new HA’s every 5 years (or less) because of evolving HA technology. But with a little improvement in battery power density compared to what EV makers aspire to ( just a 50% power density improvement for HA rechargeables?) and/or maybe a slightly bigger HA body size, 20% charged and 80% charged could be redefined as the new 0% charged and 100% charged levels and HA OEMs could extend the usable lifespan of their rechargeables without having the user really think too hard about it - and what harm would there be to give rechargeable HA users the same advice EV makers are giving their buyers to get the most life possible out of the expensive product they bought? The possibility for good battery management in rechargeables is borderline now but if no one tries, it won’t get any better and manufacturers don’t even have anything as simple as reminder alerts built into their apps for crossing user-defined low or high charge levels or the ability to stop charging up the HA’s at a preferred high charge level that’s less than 100% charged. It would be great if battery power density improved some more but in the meantime I’d like better facility in the smartphone app to allow a user, if that person wanted, to practice better battery power management just like EV owners can with a lot of help from their car software. Perhaps its the economics of HA rechargeable batteries again- it’s not worth the effort to develop such monitoring, easier just to treat rechargeables as a longer-lived form of disposable battery.

Simple Calculation Showing a Small Increase in Size HA Body Size Could Lead to a Big Relative Increase in Rechargeable Battery Capacity.

Our perception of size is ~1-dimensional. If asked to compare HA body sizes between two HA’s (it’s been done on this forum before), we might compare the two lengths vs. each other, the two widths, the two thicknesses. If one HA body was 10% bigger in all dimensions, would that be a big deal? Maybe not. But it could significantly increase relative battery capacity. Because battery capacity is a function of volume (dimensions cubed) - the increased mass or space occupied by battery material.

If every dimension increases 10%, the volume of the hearing aid (length x width x depth) is 1.1 cubed greater, i.e., 1.1 x 1.1 x 1.1. That’s a 1.331 times increase in overall volume of the HA body. What if this 33.1% increase in volume was all devoted to adding more Li-polymer battery to the HA body? Is the HA to begin with 100% battery? Certainly not. If the battery occupied 50% of the original HA body and you increased its size by 33.1% of the original body size, the battery is now 33.1% increase in original body size to HA battery increase/50% of original body size is battery = 60% increase in HA battery size for only a 10% increase in each dimension.

OK. Let’s get extreme. Let’s say the original HA battery size was 75% of the original body. Then 33.1% increase in body size to increased battery size / 75% original body size is battery = 44.4% increase in HA battery size for only a 10% increase in each dimensions.

I think both these thought experiments overestimate the original size of the battery as a proportion of the overall HA body size so a 33.1% increase in body size entirely devoted to more battery likely would be an even bigger increase in relative battery size-if the battery were 33% of the original body, 33%/33% would be a 100% increase in battery size for a 10% increase in each dimension. But the point of these calculations is that even if the Li-ion battery already occupies a substantial portion of a rechargeable HA body, with a very modest 10% increase in each linear dimension, you can significantly increase the relative volume of the rechargeable battery and get enough extra battery capacity not to have to go between 0% charged and 100% charged in using the Li-ion battery. But users want small hearing aids and HA OEMs want to sell them new HA’s every so often so who wants to make a hearing aid bigger than the competition’s and one that lasts much longer so there’s less inducement to upgrade every few years.

So just checking to see if this was my thread. appears to have gotten off topic!

My impressions after a year of using rechargeable HA (ReSound Linx Quattro).
I don’t travel, I sit at home almost all the time (remote work).
I have never thought about the charge level.
Only two times were rechargeable batteries discharged: when I worked continuously for more than 24 hours and listened to music almost all the time. Both times I was extremely exhausted and just went to bed.
If you are not traveling to places without electricity, you can take the rechargeable version.
P.S. And in case of travel, just buy a large power bank 30000-40000 mAh (it should last 10 weeks and more of HA use).

Went on holiday last week, forgot my sponge bag and charger. How I wished I had batteries!
Luckily my daughter was able to get them and send the charger to me.

Yes, this is a disadvantage.
But you can forget the batteries too. They are easy to find in big cities, but difficult in small towns.

I know this is a pretty old thread. And some may have already addressed my points already but as far as I’m concerned, unless you have dexterity issues, replacement batteries are MUCH more convenient and cost effective than rechargeables.

You’re not tied to a charger (the thought of another thing to charge daily makes me cringe), batteries are available almost everywhere if I forget to bring backups (but I always have 2 on my keychain, anyway) and the cost can’t be beat. I use 13’s, and with ~16 hrs of daily use (of which at least 6-10 hrs is streaming) I get 8 days on average from a pair. I always change in pairs, regardless, when one chimes to be changed. At $8.29 for 48 batteries from Costco, that’s 24 pairs that will last 192 days. Less than $17 for over a years worth of power and my aids are always ready and available for use. To me this is absolutely a no brainer!

I once felt your way, but I get my aids from the VA as I am a disabled veteran. So it has never been a money issue for me. I personally now find rechargeable aids to be more convenient and even time saving, if only a few minutes. I no longer worry about a battery go dead in the middle of an important meeting or appointment. As for as the charger, well I keep one available in my to go pack for over night stays. I have to do that for my phone and laptop anyway, so it isn’t a big deal. I love camping and it is easy to charge the aids in the vehicle, camper and even a battery backup charger I keep in my go pack. The charger weighs nothing and takes up very little space a small 3000 battery backup keeps the aids charged for about a week.

@mrmeyers said:

and the cost can’t be beat. I use 13’s, and with ~16 hrs of daily use (of which at least 6-10 hrs is streaming) I get 8 days on average from a pair… At $8.29 for 48 batteries from Costco, that’s 24 pairs that will last 192 days. Less than $17 for over a years worth of power and my aids are always ready and available for use. To me this is absolutely a no brainer!

Yeah, sounds like in your case it’s a no brainer.

But for others, like myself, my disposable batteries don’t last me 8 days. They only last me 3 or 4 days max (if I stream less). That’s because I don’t get to use size 13 like you, I’m stuck with the size 312, and my HAs drains a lot of juice if streaming. So it’s more likely to cost me $42/year for disposable batteries, not $17 like yours.

A lithium-ion battery is supposed to last about 5 years. So $42*5 = $220 for 5 years cost of disposable batteries. I’m guessing that the Lithium-ion battery replacement (assuming that you can easily replace it yourself and don’t have to send it in, which you can in some HA models), is about $50/battery or $100 for a pair. So the economics don’t always work out in favor of disposable batteries. It varies per individual cases.

So since original post life has changed. Trailed Rexton rechargeable and they were horrible. Costco HIS adjusted to level he said would restore my hearing. I have had this HIS for a few years and have been happy with him til he made this statement. Have Octicon Ruby 2 rechargeable for a month now. Aetna Medicare Gold plan paid for them so got them. Even paid for molds.
Work in extreme heat and sweat a lot. Appears rechargeable sealed better since no battery door to break!. Only issue when they made mold they put vent on bottom so they clog with wax. Getting remade. Hearing better than old Resounds. Audiologist doesn’t have REM that worried me.

Had COVID in December in ICU for 7 days. Still recovering from that so hearing aids were low priority.