Yeah @auntpie… You open up a can of worms, by breathing new life into this thread…In truth, rechargeable aids only work mild/moderate & “Some” severe thresholds, occasionally into profound with 105db receivers… But, for most severe/profound losses, the battery drain would be very excessive, so these Super Power BTE’s (SP) or Ultra Power BTE’s (UP) aids, cannot work at present with rechargeable LifePo4 Batteries, they aren’t powerful enough yet, so 675 or 13 batteries, are the only game in town! That, I believe is about to change in the next few years… Nissan is developing “ A Lithium-Ion Solid State Battery” capable of storing “Allegedly” 4 times the energy, or 1200 miles, on a 10 minute charge, these batteries are much denser than Lifepo4, and might, if successful, see the demise of the “Automobile Industry” as we know it? I am almost certain the major hearing aid manufacturers, will be developing their own type, solid state or whatever? Personally, I am Pro rechargeable everything, but only if they are fit for purpose, at the moment rechargeable doesn’t cut the mustard for my loss, we are not there yet, but I think and hope that is about to change… LifePo4 batteries have a couple other drawbacks, when they short circuit, they can cause a fire, water damage is usually the main enemy… The fumes are highly toxic, I was reading a report last week on e-cars, it would appear, electric cars are becoming a major problem for the UK Fire Service, as they become more popular, any e-car fire, is a major hazard, toxic fumes are one problem, the other is it’s extremely difficult to put a battery fire out, the preferred method is to let it burn, but it takes about 4 hours or so to burn out, and the fire can restart at any time, so waste disposal companies will not look at them, and refuse to accept them! Not to mention, it’s time consuming for a busy Fire Service! Rechargeable hearing aids have a BMS (Battery Management System) they will cut out in subzero 0-C temperatures, this happened twice to me, in challenging circumstances out in the sticks, with rechargeable aids, the aids will not reboot until placed in the charging dock! I would imagine, once these new batteries are developed, 4 or 5 days runtime might be feasible for under an hour charge? At present there is no perfect solution, one size doesn’t fit all, rechargeable is a reasonable solution for the vast majority, and as the battery technology becomes better, hopefully we shall see a vast improvement on hearing aid runtime & charge time… As always, YMMV… Cheers Kev 
Well, yeah, but none of that is an issue for rechargeable HAs. Of course you didn’t mean that it was, but sheesh, for someone on the fence, for whom rechargeable aids are appropriate, all of that might seem frightening.
For the majority of HA users, rechargeable aids are safe and secure option. I was a replaceable HA battery user. My new-ish aid are rechargeable, and I was skeptical. Not any more! I hope not to go back to replaceable batteries. No fires or short circuits or toxic fumes so far!! And I haven’t heard of that happening with hearing aids…ever. Its’s a non-issue.
Hi @jeffrey, my apologies, I am not wanting to get too embroiled in a conversation about the merits of rechargeable v disposable batteries, both have advantages & disadvantages… Suffice to say, I wasn’t trying to be alarmist… Cheers Kev
Just being picky, but as far as I know all rechargeable hearing aids use Lithium ion batteries, not LiFePO4. Lithium ion batteries are more energy dense (thus being better suited for hearing aids) whereas LIFePO4 batteries are less energy dense (heavier) but are considered more stable and retain their ability to take a charge over more charge cycles. LiFePO4 is the preferred battery chemistry to use with solar energy systems. Here’s a link for those who want more detail. LiFePO4 vs Lithium Ion Batteries | An In-Depth Comparison - Anker US{}{}&gad_source=1&gclid=Cj0KCQjw2a6wBhCVARIsABPeH1uLPp1ApE_jLeC72tIUjJDeqCpv0eR9M-SlKGSKO0H8uBLNcwn6mYMaAgkVEALw_wcB
As far as I know there have been no battery fires related to hearing aids.
Yeah @MDB, apologies, it’s my laziness calling them the same, LifePo4 batteries are Lithium Iron Phosphate, and much more stable (safety wise) than Lithium Ion, they use Cobalt, both work similar though, the chemistry is rather different… I have both these types of batteries, I have 4kw of solar panels, with 8 x 200ah 12v LifePo4 batteries, running 2 x battery banks, of 48v at 400ah, or around 21kw at 240v, although it’s switched off just now as it’s needing tweaked, to run off the new 5kw inverter… I also have approximately 24 Lithium Ion Dewalt batteries, (I haven’t actually counted them) for my battery powered tools, running both between 18v & 54v systems, from 4ah to 9ah, I have inordinate amount of Dewalt battery tools, I am rather obsessive with tools, which I add too fairly frequently, for instance I have 6 different types of Dewalt battery drills alone, which might give you some indication of my obsession with Dewalt 
I know, it’s rather ott… I regularly rotate these batteries for longevity purposes… TBH, I would be surprised if the odd rechargeable Lithium Ion battery hearing aid hadn’t gone up in flames, on an extremely rare occasion, the law of averages say it will happen, it may be extremely minuscule though? The UK Fire Service report said 150 e-car fires last year (I believe?) with battery fires reported, but not all where reported reported as such, I have not heard or seen one, but that doesn’t mean they don’t happen, from 500k e-cars approximately in the UK… Personally, I had a new BMW i3 e-car for approximately 18 months, range anxiety eventually got to me, charging points around the Scottish Highland’s where few, and far between, so I got rid of the i3, I loved driving that car though, there is something about quietness (apart from wind noise) and the sheer torque of an e-car is quite exhilarating! For someone who doesn’t like driving, that says a lot… Cheers Kev
I can’t prove a negative, but I don’t think the law of averages says a rechargeable lithium ion hearing aid will occasionally go up in flames. I’m no expert but I think susceptibility to fire is related to the mass of the battery (bigger batteries being more susceptible to building up heat). Since hearing aid batteries will by nature be pretty small, I don’t think it’s a given that it will happen. The only report of a hearing aid fire was connected to a zinc air battery (non rechargeable)
Sounds like you have a pretty nice solar system and an amazing amount of battery powered tools! :>)
You didn’t come off as alarmist, or controversial! You know a hundred times more about rechargeable batteries than I. I just wanted to underline their safety for hearing aids.
Thank you @MDB I see the logic in your argument… Funny enough, some LifePo4 battery banks, have built in heaters, to keep the batteries at above 0-C, if not, in subzero temperatures, the the BMS will kick in, making them inoperable or indeed unable to be charged…
Thank you @jeffrey, I am much obliged for your kind words, but in truth, I am no expert, I know enough to get bye… Cheers Kev 
In a word “NO”. My Jabra EP20 holds a charge for several days, although I don’t tax it with challenging usage.
I’m retired and do lots of outdoor activities, downhill skiing, winter steelhead fishing, boating and camping. I stream books while doing house chores, yard work etc. The Kirkland 10 rechargeables (by Phonak) were a headache. The batteries were dead by 8 PM most days. If my ski goggle straps or fishing glasses hit the power button for over 10 seconds they went into standby mode and needed a charger to restart them. Total pain in the butt. The “brick” was always having to carry on my person a small battery and a custom made mini charger, just enough to reset the HA’s. I also discovered that most small 5.5 volt USB personal chargers have a voltage protection circuit that shuts off after a certain time (10 minutes or less) as the circuit reads the very low HA charger amperage as a voltage leak. If you try your cars accessory mode that will turn off after 20 Min, not long enough to get a charge overnight camping. I see most newer chargers have a built in battery now to correct this problem.
While camping I had to have a small 12 volt battery that would maintain a “power on to” state charge the HA’s at night.
I’m replacing them with battery type Jabra Enhance Pro 20 (RIE 13) from Costco. I’m tired of dead or un bootable rechargables. I always had to kept my old battery types with me as I knew I’d be needing then by evening. In 10 years of wearing battery types there was one time I forgot to bring a battery with me to a party. Guy two tables over had spare batteries!
If you are concerned about having batteries types go dead just replace them on a timely schedule based on your use pattern.
PS: I had Costco replace the batteries twice in the rechargable Kirkland 10’s. Never made a difference.
PSS: One thing I loved about the Kirkland 10 was the volume button becomes a fader button when streaming any sound source from my phone. It allowed adjustment between outside and internal sound sources. I’m going to miss that.
I was just about to get the Lumity Rechargable to try out last week, and read a post on here that someone was taken to hospital ill. That night he lost power in his rechargeables while in hospital.
It reminded me of a few years ago when my wife fell on our doorstep and broke her arm. It was about 8pm and I took her to hospital. We were there until 3am the following morning and it dawned on me I would have lost HA power at 11pm or so. With profound loss, an already difficult and stressful would have been severely compounded with no HA’s.
Pro’s and cons either way, but for someone with profound loss, I’m not there on rechargables as yet.
My Audi did say that approx 90% of his clients have rechargeables. The other 10% or so with disposables are mainly in the profound loss bracket.
If there could be a universal charging method, even as a backup that may be slower, then hospitals could keep some chargers on hand. Do hospitals stock hearing aid batteries? Could the current wireless charging tech be crammed into a hearing aid shell?
With your active lifestye, I’d not only go with disposables, but also try and obtain a spare pair of aids, again disposable. These spares can lie idle for months, but can be instantly ready, with a fresh pair of batteries inserted. A rechargeable spare pair would need recharging if left for months. I find them just more practical.
Peter
For those who have problems with their rechargeable batteries not lasting long enough, I can report that with the bluetooth on my phone turned off, and my Costco Rexton R-Li T (telecoil) hearing aids turned off at bedtime and turned on in the morning, with no recharging, the batteries functioned for a true total of 39 hours before dying. From what I’ve read, the current Rexton Reach should be similar.
Forgetting to charge them or leaving the charger behind is operator error, no fault of the hearing aid.
Not being able to find the charger because it’s black and got ‘lost’ in a suitcase lined in black, as I did, is user error, too. With rechargeables, I lost the use of the aids until I found the charger. With disposables, I can get the aids back online virtually anywhere I’m going to be.
Absolutely you should be… You never know when someone may deploy DEWs and suck all energy from your area. Maybe you misplace your charger or a tornado, hurricane whatever hits your area. Maybe end up in the hospital and have no friends or relatives to bring you your charger. Your AuD won’t have someone drop one off to you. Hell I can get one from amazon in a couple of days.
Have you tried to buy a charger? I called multiple ReSound dealers and Costcos. Everyone told me I had to wait 2 weeks.
I imagine my home Costco would have helped me more, but I was 1000 miles from home.
I’ve had to change batteries mid conversation, but only occasionally because I will replace them in advance if I know I’ll be needing to talk to someone and it would be inconvenient to stop and change them (e.g. a Zoom or Skype call). If the batteries give out during a physical chat, I just get on with changing them. I don’t see anything to be embarrassed about.