This is the 5th part of my wishlist to audiologists and accousticians, hearing aid manufacturers, and the health care system. If you like to add something, share your experiences, or provide more information, I encourage you to submit a comment.
Peripheral hardware often needs their own batteries. Those are very often proprietary batteries and most often they don’t last very long. For example in order to use my bluetooth adapter a whole day, I need to buy an extra battery for it and often a charger station as well (if available at all). And situations where this is necessary are common for example when you travel have nothing else do to than listening to music while sitting in the air plane for 12 hours.
I would rather prefer peripheral hardware to use normal non-proprietary batteries which are available in every grocery store in the world and that I can use my charger for normal batteries for. And please don’t tell me those proprietary batteries are necessary for the design of the devices, most of them look dorky anyway, so I might at least have the benefit of using non-proprietary batteries.
See also the next point on my wishlist: Affordable hearing aids and full insurance coverage for devices and peripheral hardware and maintenance costs. Or the previous one: 24/7 Service and Availability of Replacement Devices.
I would like to know why hearing aid batteries are not rechargeable. It would be absolutely straightforward to recharge them at night, while sleeping. I don’t know anyone who sleeps with their hearing aids in.
You’ll need to know that the HA batteries are at one hand one of the powerful energy sources on market, and on the other hand they’ve got over a long time continuous power. For example a flash light is bright and getting darker and darker by time. For your HA, it would decrease needed volume over time. The power of a HA battery hard decrease at the last few minutes, depending on environment up to two hours.
Why not rechargeable? It is a capacity problem.
A accu with the size of a HA battery (13) got for 1,3V enough power to give power for round about 10 hours, if they are new. During the lifetime it will rise to 8h. And after 2 years, you buy new one. Even my grandma was more than 8 hours awake.
The cost for the technique, the charger and the batteries was in 2008 as much as you’ll pay for roundabout 2 years HA batteries.
Since the first tries I’ve seen from Hansaton[1], there are a lot of improvements from Siemens[2]. But I haven’t heard of a system, that don’t need a ’emergency battery’ for longer days.
I’m pretty sure all big player on market got at least one blueprint in their desks and right accu technology.
[1] http://hansaton-aq.com/
[2] https://www.medical.siemens.com/webapp/wcs/stores/servlet/PSOptionProductDisplayView?catalogId=-201&catTree=1028665,1028577&langId=-201&productId=200392&storeId=10001
In the beginning when I got my hearing aids, I was full of motivation to treat the environment (and my wallet) well and use rechargeable batteries. They actually exist, but they only last 8 hours. As LupusE explains, this is because they have to be that small and the industry has not managed to increase their capacity (yet, I hope). I also heart the rumor (but don’t have any sources) that this is because one hearing aid manufacturer has the patent on “using rechargeable batteries in hearing aids”. Thus, other vendors don’t dare to even advertise using rechargeable batteries.
Anyway, I bought a set of those rechargeable batteries. Of course 8 hours are way to short for my day, so I planned to switch to normal batteries or another set of rechargeable batteries after that. The first problem I ran into was that the charging station that was available from Siemens required to put the complete hearing aids with the batteries in there. There was no way to only put the batteries in there. Of course that is not possible if you still want to wear the hearing aids after the first 8 hours of the day. I wonder who thought of this stupid design.
So, the second step was to buy a charging station that does not require the hearing aids being placed in it. I used it for some weeks with two sets of rechargeable batteries, but it turned out to be really impractical. You have to switch them in the middle of the day and of course it is always in the most inconvenient situations. You have to have the charging station with you, because if you wait until the evening, you need it to recharge the second pair of batteries.
Switching to normal. non-rechargeable batteries after 8 hours does also not really work out, because when you wear your rechargeable batteries the first 8 hours on the next day, the normal batteries are lying around and because they are zinc air batteries, they continue to loose power no matter if power is consumed or not.
So, all in all, I meant well to save the environment, but actually it was a costly experiment. Btw, if someone is interested in buying one of the chargers. I still have them lying around.
Bluetooth is an extremely power-hungry technology, this is not the fault of the hearing aid designers. If you leave bluetooth active on your phone the battery drains a lot more quickly, especially if you stream signal through it. The peripheral devices you speak of are generally simply digital converters, they convert the bluetooth signal from a bluetooth device into a signal that can be accepted by the hearing aid. If the bluetooth signal went straight to the hearing aid the battery performance would be terrible.
Everybody wants a small hearing aid – the amount of features, functions and technology they fit in such a small space is actually quite astounding, especially considering that for some hearing aids the battery compartment takes up to 1/2 of the space of the casing. The compromise of small hearing aid size is small battery size which means limited capacity.
A standard 312 size battery for hearing aids has 180mAH of capacity. This is about 1/10th of the capacity of a standard smart mobile phone and probably 1/30th the capacity of a laptop battery. A Siemens rechargeable 312 battery has 31mAH of capacity.
I think the wish should be for higher capacity batteries or more energy efficient wireless protocols.