WHOA!
The airwaves are on fire this morning!
I have no idea if it will be the case for Oticon, but Phonak had features in their Paradise line that needed the higher voltage of rechargeables to work. (I believe motion sensors and their tap feature) Phonak has a disposable battery version, but it lacks those features. I guess it would be conceivable to run disposables in series to get higher voltage, but then would really run into space issues. I wondered briefly if higher voltages yet might be needed for the future, but since lithium ion rechargeables allow the same voltage to be used as smartphones, I’m pretty sure that won’t be a thing. Laptop computers and desktops do require higher voltage.
One thing I like about disposable batteries (and devices that have easily removable rechargeables) is that it provides a sure fire way to reboot the device. I’ve had several occasions with a chromebook that I wasn’t sure if I was going to be able to get it to restart. Never had that issue with a laptop with a removable battery. However, for that matter, I’d never had that issue with a smartphone.
My “crystal ball” (which is not at all reliable) suspects that high end hearing aids will only be available with rechargables, but that lower end models will still be around with disposables for some time.
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You’re right about the increased voltage for certain signalling functions, but it goes deeper than that.
If you’ve only got 1.2v on tap you can use some pretty clever fast voltage splitting techniques to make it about 2.4v functional.
Now you wouldn’t think it would make a huge difference, but getting this to over 2v makes a huge difference to the design of the spacing and mass of the components within the condenser mics. Consequently you can make mics with lower noise floors. Which in turn yields to wider input ranges and more natural sounding hearing aids.
And as we ‘all’ know as you increase the voltage, you proportionately drop the current; so lower battery drain. So if you design hearing aids to take advantage of this, making a 312 version is going to become harder. The voltage produced by a standard 312 cell has been one of the biggest design constraints of modern hearing aids.
So aside from arguments about convenience, the driving factor for new innovation is likely to be the extra voltage on tap and what the engineers are able to do with it.
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… as I was saying!
Thanks @MDB, for this real world example of voltage trumping mWH as an operant definition of “power”.
Thank you @Um_bongo
FWIW, I agree, since this is a battery technology issue, and not a HA issue. There seems to be no incentive for the battery industry to tackle the voltage-in-a-button-battery issue, since sophisticated devices have always used rechargeable Li-ion.
[To a greater and greater extent, disposable batteries are being relegated to products like toys, flashlights, remote controls, guitar tuners, and bikini line trimmers.^1]
Why not, @Volusiano? I say, “Why not?”
[This is what we do when we’ve nothing better to wile away the hours than watch “Perry Mason” and “How to Get Away with Murder” reruns during the interminable winters “Down Under”. It’s like broadband axe throwing!^2]
Giv’er, Boys! Giv’er!
[1. 
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[2. 
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I am a great believer in choice…… We are quite diverse in our likes and dislikes, perhaps this makes us uniquely individual, just like our hearing loss! For me, if a hearing aid requires more hardware or bigger batteries, make it so, be that a headband, neckband, or BTE hearing aids the colour and size of bananas, I don’t care 2 monkeys who sees it, or associates me with being hearing impaired, I want them to be acutely aware I have a severe/profound loss, and I need their assistance to help me communicate with them and others……. Make them large, bold, and loud (pun intended) perhaps even a fashion extension, let us not hide our disabilities, but openly promote it, the hearing world cannot assist us, if they are oblivious to our need, in is not an inherent weakness to show that you require help, you have a severe disability! For me the greatest embarrassment with hearing loss is not the actual aids, tis having to ask people to constantly repeat! I have worn both rechargeable, and disposable…… I abhor rechargeable hearing aids, I dislike them with a vengeance, after a couple of bad experiences with rechargeable! We are all biased, we all like certain things, and dislike others, but your preferences will not alter mines one iota, and vice versa…… Individual choice, our preferences, and our biased opinions, make us who we are…… Cheers Kev 
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On the flip side, UP BTEs that use 675 batteries do not seem to be available in rechargeables. Is that because they cannot make a reasonable sized aid with rechargeable (power density issue) or more of a cost issue of not worth developing it for such a small market (and a market that is being encroached upon by CIs)?
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This does not seem right. Calculating watts will correct power usage. You are correct about voltage going up and amps going down but watts are the same. In my humble opinion.
Higher voltage will allow for smaller conductors which is a good thing in hearing aids.
UPower BTE’s are a different kind of market in a couple of respects.
1, Users are going to need 100% up time on their aids as they often struggle to function without both ears running properly.
2, There’s a requirement that they often need to perform in educational and NHS situations where charging isn’t so easy to facilitate over a period of time.
3, A 675 has a longer operating window, better life-cycle than a 312/10. It might not seem that relevant, but if you’re only changing batteries once a fortnight anyway, the opportunity cost of the charging system is way greater than the disposable system.
4, There’s more legacy considerations in market that turns over more slowly.
5, The product releases are invariably smaller and less in demand, especially in the high end sales led part of the market.
However, despite all of that, they will eventually arrive. The entire market is pretty much predicated on the RIC rechargeable/wearable aspect of the product. Manufacturers are even forgoing updating their ITE lines (Oticon; I’m looking at you….) in pushing the R+D in their next RIC. I can see the power BTEs being dragged into the same effort.
I’m wondering when we’ll see the first crossover chassis/chips shared across two or more main manufacturers (not ones from the same group) with different badges and outer shells, like they do with van bodies and washing machines. This will allow for better integration and wider product lines.
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Batteries are rated Ah.
If you raise the voltage and the resistance remains constant, current has to fall proportionally.
We aren’t measuring power (W).
The voltage splitting systems oscillate the 1.2v between 0v to 1.2v to 0 to -1.2v and back to 0v 50,000 times a second. This allows you to ‘create’ a new 0v rail and one at 2.4v.
Ohms law still has to apply as you can’t create that from nowhere, so the mic side uses half the uAmps to provide that signal.
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I really hate to differ with you but watts and amps are power.
DC voltage (batteries), amps and watts go hand in hand. As ohms and watts law state.
I only disagree with the battery drainage is less at higher voltage statement. That just doesn’t make since using ohms and watts laws.
Not an expert, just enough background to be dangerous.
Maybe my error is a battery can hold more amps or watts at a higher voltage.
That may explain more Ah.
Still learning, never stop learning.
It’s covered in this; the premise of voltage splitting and creating a 0 and 2.5v rails.
Widex claimed in their release of the Evoke model around 2010-12 that they used this technique to reduce current draw by the voltage splitting techniques; the appended claim was that by doubling the voltage, they cut the current drawn.
I argued with the guy who presented it at the time that the amount of work (the area under the curve) was the same, but they (the Widex Engineers) insisted this wasn’t the case; in a room full of physicists I might have had a chance, but in a room full of Audiologists, not so much.
I’m not going to hang my hat on either version being correct; however as that’s not the point of what’s being said - there’s more voltage available from LiPo, LiFe and other forms of recharging batt systems than you get from a zinc oxide cell. And if you do the same voltage splitting technique, you can stretch that further. That’s a big removal of the constraints on circuit design.
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I think the answer is that you actually ‘draw’ more effort from the condenser mic, but don’t ask me how as I’m still not entirely sure how in a permanently charged sheet of Mylar wafted at another surface, doesn’t dissipate it’s own charge over a very short window.
(Where do the electrons come from?)
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Power (watt) = Voltage (volt) * Current (amp), so with the same amount of power drawn, if the voltage is doubled, yes, the current will be reduced in half to satisfy the equation. That is why power lines are operated at very high voltages in order to deliver the same amount of power, because the higher voltage can lower the current, so that the need for very large/bulky wires to handle higher current amounts is not necessary.
Power is instantaneous. Energy is the capacity of the amount of power that can be delivered over time, which is expressed in Watt*Hour.
A battery, depending on its chemistry, delivers a fixed voltage (and a somewhat constant voltage until it’s drained down/out), and its capacity is in how many amps it can deliver for how long under this voltage. The Ah (amp*hour) rating of a battery is an indication of the battery capacity (total energy availability) for the fixed voltage that the battery can deliver. Even if the voltage is not mentioned in the Ah rating, it’s still part of the equation to calculate total energy capacity of a battery.
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It all goes hand in hand. There s a balance that is there all the time, more resistance the less current for the same voltage. Every thing in nature and life has to balance
Most batteries I know of have non-zero internal resistance - the higher the current delivered the higher the internal loss (shows up as heat). That also leads to a lower voltage available at the battery terminal with load. So the power delivered to the load form a real battery is not as one might expect from the voltage rating. Some rechargeable batteries have very low internal resistance - a good thing for efficiency. Another issue I don’t see mentioned - most any power conversion device (say convert the battery voltage to a higher value) is not 100% efficient so using a higher voltage source (from a lithium battery) would be more power efficient than converting a lower voltage (from a zinc air).
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No we may not be measuring wattage but is is still part of the total equation.
I hope you’re right about August 10th being the magic date for disposable battery versions for Oticon Mores! Been waiting on the fences for a while!
@gkumar: Don’t hold your breath. Oticon is notorious for pushing back launch dates. Search the Forum for ConnectClip and you’ll see.
Possibly relevant:
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