Choosing a power bank for my hearing aids

[Martin Dunschen]

DoES Electronic Boffins!

I've been using hearing aids for some months now. They come with a charging case that plugs into a USB adapter. The adapter is rated with 5V 1A output. Other adapters with a similar output also work. On a camping trip I found that I could not charge the hearing aids with a 2200mA 5V power bank: The case, the aids sit in for charging did not light up it's LED, and it's obviously not charging. However a small cheapo solar panel with a USB charging port worked fine in sunny conditions (not so well in overcast conditions though).

Why would a 2200mA power bank not work? 

Thinking of getting a power bank to use with the aids, should I use something even higher rated than 2.2A, or something with 1A?

I'm really confused why it would not work with the 2.2A?

Thanks, DoES community.

Martin

[James Ryan]

Hi Martin

USB power delivery is a bit of a mess of standards, not all of which are implemented as well as they could be.

I have an Anker power bank which will detect and begin to charge most things.  But I also have an electronic conspicuity device based on a Raspberry Pi 2, which it refuses to detect until either some other load is connected, or I press the battery indicator button on the side, which wakes it up.  Presumably the pi in pre-boot state isn't attempting to draw sufficient current to wake the thing.  A hearing aid charger is likely to be a pretty low powered device.  So can you wake the power bank in some way?

There are further horrors around USB C power delivery, and I've heard of devices fighting with each other over who gets to charge who.

--
You received this message because you are subscribed to the Google Groups "DoES Liverpool" group.
To unsubscribe from this group and stop receiving emails from it, send an email to does-liverpoo...@googlegroups.com.
To view this discussion on the web, visit https://groups.google.com/d/msgid/does-liverpool/CAK55gbDafydEJ1VMiA_vhmk8bq_56aV0XETHfkKaV87O7pc6qA%40mail.gmail.com.

[Martin Dunschen]

Hi James

Thanks for your explanation. Yes, I can wake up the power bank, and it behaves then as if it's charging something while connected to the hearing aid charger. Interesting what your say about USB C, the hearing aid charger uses a USB C connector.

I found now that a small 1A power bank might work. So, it might not have anything to do with the output of a charger but with some other spec related USB stuff?

Martin

To view this discussion on the web, visit https://groups.google.com/d/msgid/does-liverpool/CAKi5-TbPPYc-O39KC2HqXL1nhL991Q%2BsqsA3XymJxqA3s%2BEETA%40mail.gmail.com.

[Chris Huffee]

Hi Martin, 

I suspect the issue is less to do with the capacity of the power bank. (The 2200mah figure) More that the device you are charging doesn't draw very much current when charging and so the power bank shuts off. You'll need a powerbank that supports 'trickle charging' for your hearing aids.

This link explains it more clearly.

https://www.powerbankexpert.com/low-current-trickle-charging/

To view this discussion on the web, visit https://groups.google.com/d/msgid/does-liverpool/CAK55gbB_tpBM7rrRbgGbZYRF-dvkJGAYuWpo%2BiuApygB6BxezQ%40mail.gmail.com.

[Martin Dunschen]

That's very helpful Chris, I've learned something, thanks.

Martin

To view this discussion on the web, visit https://groups.google.com/d/msgid/does-liverpool/CA%2BYzHgk3s6EcviAp0o-pfrb1-GXNFj2OjeiDN2XczpOVfiLTMw%40mail.gmail.com.