I think I’ve hastened the early demise of a couple speakers with my well-intentioned swabbing of them and the silicone tips with alcohol prep pads. Now I use Audeo Wipes.
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Those shots make me respect my aids! I had no idea there was so much going on inside, especially when they stop performing and I want to grind them under my heel in frustration.
I can sure see how my so-called “waterproof” Lumity Life aids would’ve drowned after a couple dunks in the pool. There are just way too many sensitive electronics here, and obviously, either the speaker or BTE unit is not waterproof sealed after all.
Any idea what’s in that matchstick-sized speaker/receiver?
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I’m pretty sure battery can be replaced without replacing the translucent plastic case / wire. From what I can see the contact between the wire and battery is not soldered. Might need to re-apply a coating after opening the battery case to maintain structural integrity / water resistance.
I was hoping someone would get bored and rip one apart for us.
There are normally spot-welded connections on larger lithium ion batteries: soldering such cells inside batteries can harm them as the temperature required to melt and flow the solder is well above what the chemistry can tolerate.
Even 18650s need spot welding so especially for a cell as small as the one here in the photos there’s no way it could survive any direct soldering.
I agree that it looks like the cell can be extracted from inside the plastic case, I was just pondering what the actual procedure could be for a Phonak trained engineer to save on time and cost. Those big lumps of solder just look suspiciously manually applied to those cell wires.
Are you asking about any hearing aid receiver for RIE style hearing aids (not shown in the above pictures)?? If so, then I believe that inside the receiver is balanced armature technology;
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An alcohol swab is 70% water plus 30% water. It is good for cleaning the dooms. The doom becomes clear and clean after cleaning with an alcohol swab. The thin layer of ear wax in the domes is removed after cleaning. It is done every 2 weeks. As for the HA, using a piece of tissue or the cleaning velvet cloth will do. Remember to use the brush to clean the MIC.
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That is exactly what I was wondering about! That little bent matchstick you’ve posted a picture of. WOW. This is better than Mr Wizard’s Science Hour! Love how all you folks come together to provide the answers to these tech questions.
Now I can see how even a tiny bit of moisture inside a speaker could be the kiss of death, too. Magnets, coil, diaphragm - none would perform well when soaked.
The distortion I heard at first when I swam with my Life aids was like a diaphragm issue - crinkly, crackly and almost like voices were coming from a well. But then the aids went into a steady, loud BUZZING sound, so that makes me think the electronics were fritzing - like a radio that drifts from the signal and just puts out static HUM.
Cool.
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I’m 99% sure those battery wires are spot welded at the battery case and hand soldered to the terminals that are part of the printed circuit board (PCB). The only way to automate that would be to very precisely and consistently form those very flimsy wires. It’s not practical. Tiny HAs are not laid out in a fashion amenable to spot welding both ends of those wires.
Hand soldering can be very quick (as in seconds). You just use a relatively big iron to heat the joint locally and quickly before the heat can get to the battery. It’s quite a common technique.
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Yes, agreed. That is what I was suggesting.
Please help. 70% water? 30%alcohol? or the other way around.
Question I have is, how does the wax get on our domes? Is it rubbed on? or is there a change of state?
I really am asking how do wax guards work? I’ve talked to so many seniors that wear HA’s. They don’t know they have wax guards and never change them. All those little holes must surely be plugged. If so, they have rubber earplugs in their ears, not hearing aids.
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Wax can be in various forms: dead skin cells, oil, moisture. It depends on the person’s ear. Some people have no wax at all! The domes do pick up wax, and could be rubbed on. Hearing aids can cause more wax build up, depends on the person’s ear. I also apologize in advance if my comment isn’t clear, it’s still early for me 
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Did a bit more digging online for the battery. If the previous measurements from the CT scan is accurate, the battery size should be identical to size 13 hearing aid battery. However I wasn’t able to find any li ion size 13 batteries.
I did get a few hits by searching with the metric measurement “854”. Moreover the size 854 agrees with the etching on the battery. If you search lir854 you’ll get some results from Chinese manufacturers who are making those. Not sure if I would be willing to put them in my hearing aid.
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You’ve helped a lot.
As I said, I’ve talked to many seniors who didn’t even know they had wax guards that needed to be changed.
I have a pet peeve with the P90R’s wax guards. I have nerve damage in my hands; changing wax guards isn’t fun. With the little lock strips it was impossible. Not a step ahead; it’s a design failure.
DaveL
Toronto
Varta make a battery that is very close to this a CP7840 F which is 7.8mm x 4.0mm and appropriate for medical devices: maybe the ‘854’ is part of something like CP7854 which would make it 7.8mm x 5.4mm which is exactly what we are after.
We just need to find a supplier…
EDIT:
Found an equivalent, LIR7854:
https://www.alibaba.com/product-detail/M7854S1-Q06-LIR7854-3-7V-25mAh_1600617598948.html
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Wow never thought of 7854. Thanks to you I think I actually found the correct battery:
The battery should be CP7854 by Varta in the pdf above.
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It looks like the wire is soldered to a small nickel plate which has then been spot welded to the top of the cell.
I think that I can make out the two dimples on the nickel indicative of the spot welds but it could just be my confirmation bias.
Yes, I recall seeing another image where two spot welds were clearly visible. I will see if I can find it and post a picture here. Here it is;
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I don’t think the wires are spot welded to the battery. I think the contact is simply made by pressing the naked copper wire against the battery. That’s why I think the battery could be replaced by opening the case.
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