Buying used Rechargeable hearing aids? - Be careful

[pvc]

Oticon:
The first generation of Oticon Rechargeable ZPower had issues. I won’t get into the issues in this topic. But personally, if I were to inherit a pair of these HAs then I would change the battery doors back to old doors that accept disposable batteries. Oh wait; Good luck with finding battery doors. I don’t know where to find them? Oh wait again; You can still use disposable batteries even with the ugly rechargeable doors so there is no need tho change doors…
https://www.youtube.com/watch?v=-phC8yQ21wU

The next/(current-2022) generation of Oticon Rechargeable HAs have less issues. And, if you can find a source for purchasing Oticon rechargeable Lithium Ion Batteries (currently about $80 each) then the batteries are replaceable;
https://www.youtube.com/watch?v=Qx4NNE5BOwk

Phonak:
Phonak Rechargeable hearing aids; Now that’s a horse of a different color. It appears that Phonak rechargeable Lithium Ion Batteries are not intended to be replaced. Instead, maybe you will have to send the hearing aids back for expensive $factory-repair$. Which may be okay for HAs still under warranty. But after warranty expires, Be Careful.

Some details about Phonak Rechargeable HAs were revealed with the B-Belong platform;
https://www.hearphonak.com/lithium-ion-batteries-reliable-choice-phonak-hearing-aids/

Watch this video at (1 minute and 30 seconds) to see case removal for Pkonak Audéo P Paradise. Maybe this is what we would have to do? But what happens to (Ingress Protection/IP rating) after opening the case on the Phonak?
https://www.youtube.com/watch?v=kJc4N6IEohk

Is this what we have to look forward to when obtaining used Phonak rechargeable HAs?

• Case tear down
• Open the battery compartment
• Replace the battery

and guess what happens with Phonak’s hermetically sealed Ingress Protection/IP rating?

I am guessing that the Green-PCB electronics will remain inside the black battery case while the Lithium Ion battery easily slides out after the cover is removed.

[Markismus]

One of my aids is starting to go off after 18hours. So what batteries would be usable for the Phonak Marvel Rechargeable?
And how to replace them? A quick look suggested that wires are directly connected to the cell. That is another problem.

[pvc]

I don’t know if that black battery case enclosure from B-Belong is an accurate representation of the battery connection inside later model HAs.

If I am looking at this correctly, the Phonak M-Marvel Rechargeable HAs and the P-Paradise rechargeable’s that follow, don’t have battery doors. They have two (+/-) charger contact posts on the bottom-rear of the case, and the case is pinned by one case pin at the top-rear of the case.

Because there is no battery door, I am thinking we would need to do a case tear-down to view how the battery is replaced.

But, if the intent for not having a battery door is to force factory-repair for all Phonak rechargeable HAs, then I am worried that access to a readily available replacement battery may also be restricted to factory repair. btw> I am not suggesting than you need to tear-down your Marvel

[pvc]

I found a video review of the Phonak Paradise rechargeable. The review itself is not very interesting. But if you are quick with clicking the video Play/Pause buttons then you can capture some still-images when they show fast moving parts illustrations.

It appears that the battery is encased inside that black container with a cover that screws on. I doubt that it has a wire soldered directly to the battery. At least now we have clues as to what it looks like.

Remaining questions;

1. Where to find a replacement Battery?
2. What happens to the IP rating for moisture control if we open the case?

[pvc]

Updates; I searched these forums for information about (nano coating/IP rating) in a quest to find out what happens to the IP rating for moisture control if we open the HA case? Whew! Nobody knows, especially regarding factory repair and whether the factory would somehow re-apply nano coating? Personally, I am not going to worry about this, and open the hearing aid case when I need to do so. YMMV.

Also ZPower was used by several manufacturers; Here’s some comments from a popular seller platform: ZPower is the only manufacturer of its patented 312 Silver-Zinc rechargeable battery. Other ZPower batteries sold are surplus from hearing aid manufacturers sold by unauthorized parties. These batteries are either damaged or over a year old and expired. Leading to numerous comments from those who have bought them over short life or do not work. Do not buy these batteries. Buy direct from ZPower instead. ZPower Silver-Zinc batteries, made in the USA and shipped direct to you.
Compatible with ZPower Rechargeable Hearing Aids from the following manufacturers:

• Starkey- Unitron- Signia- Bernafon- ReSound- Widex- Beltone- NuEar- Audibel

[Vigilo]

Just popped an Phonak Audeo B70-R apart.

The battery in it is : a Power One Li-on accu -120

https://www.powerone-batteries.com/en/products/accu-plus/p13/

Looks like they’re soldered in place though (beyond me to replace)

[michael1]

Hi, if you are tempted - be careful!, lion don’t like heat, probably done with a laser.

[Markismus]

@Vigilo

Looks like they’re soldered in place though

Yes, the same with my Audeo M90’s. Soldering batteries is a very bad idea. It’s to small for point welding, though. Maybe if that paste solder for SMD (surface mounted device) is used, you can keep the temperature lower.

[pvc]

Yikes, rechargeable batteries soldered in place? Why would the manufacturer design it this way? Maybe planned obsolescence to kill the market for their used hearing aids??

[Markismus]

@pvc

Maybe planned obsolescence to kill the market for their used hearing aids??

Seems a little far fetched. If you rephrase it to “design didn’t have reuseability as one of its targets”, than yes.

Still, the batteries for PowerOne are 25€ in Holland, the paste is under 10€ on AliExpress. So I can change the batteries without a major hassle and costs. This is good thread! See next post!

I also don’t worry much about the nano coating and IP rating. I had to open my Audeo M90’s, because I had pushed the plastic holding the receiver plug too far. I have opened my B90’s and afterwards dived into the pool whilst wearing them and the damage was wholly to my mood.

[Markismus]

@Vigilo

Power One Li-on accu -120

Your link is wrong. It points to NiMh batteries. This one points to Li-ion. Can’t find a place to buy them, though.

(PowerOne’s) NiMh generates 1.2V
(Zpower’s) SilverZinc generates 1.55V
(PowerOne’s) Li-ion generates ~3.2 to 3.7V.

So if @Vigilo is correct, we’re not there yet.

[pvc]

Yep, I was able to google-search many sources for “PowerOne ACCU plus p13 Ni-MH”. Maybe first-gen Signia rechargeable HAs used these Ni-MH rechargeable batteries because I found many references for Signia. Note the warning about compatibility below;

But I can’t find any PowerOne ACCU plus p13 Li-Ion batteries and I don’t think that we will be able to find these. The battery manufacturer/PowerOne from Germany says-in-this-link “The power one lithium ion batteries are built into the hearing aids. It is therefore important for manufacturers that the service life of the cell is just as long as the hearing aid’s lifetime. The power one Li-Ion accus have demonstrated a service life of 4 to 5 years, which means they last just as long as a hearing aid. No more battery changing is needed.”

Is it too soon to say that some manufacturers may be intentionally “Bricking” their hearing aids/HAs after warranty expiration? Correct me if I am wrong. But I don’t know what else to call this? What else can it mean if the batteries are soldered in place and we are unable to find replacement batteries?

fwiw> In the past, our supply-chain friends in China tend to provide solutions for unavailable parts. But I suspect that it won’t be the same for the German supply chains.

btw> Please don’t try applying heat to Lithium Ion battery which might cause an explosion. This is what happens inside a battery right before it explodes

[sterei]

@pvc

It appears that the battery is encased inside that black container with a cover that screws on. I doubt that it has a wire soldered directly to the battery. At least now we have clues as to what it looks like

I think the video shows not all parts, the connection to the battery is missing.
Some time ago I made a 3D CT-XRay-scan of my P90R:

It seems to me that there are wires welded (not soldered) to the battery. Soldering is a no go in this case. Welding can be done in a real short time preventing the part to heat up. .
Note: There are only metal parts visible.

@Markismus

Seems a little far fetched. If you rephrase it to “design didn’t have reuseability as one of its targets”, than yes.

I think also the goal was to achieve more reliabilty. Replaceable batteries have disadvantages, contacts may corrode, sealing of the battery door etc.

Probably the rechargeable batteries Phonak uses are custom made. Therefore it will not be possible to buy them anywhere.

EDIT:
It might be possible to solder the wires on the PCB. If we get the replacement-battery with the wires attached.

[Markismus]

@sterei

It might be possible to solder the wires on the PCB. If we get the replacement-battery with the wires attached.

Or we just tape them using metallic tape (very thin). If the contact is lost, we’ll open it up again and re-apply tape.

Problem remains of how to get our hand on batteries before they die on us.

Does anyone know the diameter and thickness? Searching on Rechargable Li-ion battery button gave a lot of hits.

If they are regular orange 13 batteries, than according to this data sheet they are 7.9mm x 5.4mm and known as either A13 or PR48 (380mAh).

So if the A13 takes about a week to deplete and the Li-ion about a day, we would be looking for a battery that has about 55mAh.

Smallest one I found up to now is the LIR1254 (12mm x 5.4mm, 62mAH). LIR621 (6mm x 2.1mm, 5.5mAV).

If the estimate of 55mAh is in the right ballpark, than the LIR1254 or ML1254 has a comparable amount of energy with a width of 150%!! So that would mean that the lads at PowerOne really did some innovative engineering.

[tenkan]

Now this post is really starting to get fascinating, I’m following with interest.

[sterei]

@Markismus

Does anyone know the diameter and thickness?

I measure a diameter of 7.9 and thickness of 5.3.

[Vigilo]

Images of a B70-R

[pvc]

Wow!! Thanks!! I am wondering if these two features pointed out are Phillips head screws?

[Vigilo]

There is a single screw (the obviously visible one) - looks like it holds the PCB to the pink plastic battery casing

The other arrow (pointing nearer the silver external casing) is black resin that covers the components sealed onto the PCB

Sadly I don’t have a screwdriver that small to even attempt it - looks like its 1mm or less across the head

[pvc]

Oh okay, one screw. The miniaturization makes it difficult to visualize. Also, maybe it’s a Torx screw head or some other screw head requiring a tool that is not so common as a miniature phillips screwdriver.

ETA: This makes me wish that I could have a look at the workstations used by Phonak Repair. They must use some sort of magnification. But every time I look at workstations sold on EBay it is mostly junk, and you could end up spending a large amount of money for magnification. This linked video shows several magnifiers. Some are very clumsy. I don’t think I am ready to try magnifiers yet??