Wireless battery charging for e-Bikes

soundwave

Esteemed Pedelecer
May 23, 2015
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i can charge my phone with the case on it with a samsung charger but the phone i have needs the coil plugged in to the usb inside the case i have.

 

Woosh

Trade Member
May 19, 2012
20,370
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Southend on Sea
wooshbikes.co.uk
Sorry woosh, on matters technical you do tend to be on the ball, but in this case you have missed it. The electronics needed to power the induction coil system, whether resonant or otherwise will have an efficient of E, the resonant circuit an efficiency of T the power conditioning circuitry from mains to the transmit electronics P , the electronics to convert the recieved energy R and then the battery charging efficiency B
The total efficiency is the product of B*R*T*E*P with all less than unity.
If a direct electrical connection is made using contacts the efficiency is P*B. There are three less terms ...
you missed the same point. These coefficients are not results of added steps, they are built into the efficiency of the transformer.
Let's start with seeing that an ensemble aerial + receiver coil forms a transformer that you can characterise with a specific loss through the transfer from primary (aerial) to secondary (receiving coil). That loss is typified by the amount of magnetic flux loss around the receiving coil. If the receiving coil is large, then there is very little loss.
a conventional transformer has a ferrite core with usually high magnetic permeability which it will lose at high frequencies. An ensemble aerial + receiving coil has an air core by design and operates typically at much higher frequency, up to the low 100MHz now and many, many GHz in the future.
 

oyster

Esteemed Pedelecer
Nov 7, 2017
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West West Wales
For now, I'd just appreciate the possibility of a single standard electrical connection!

Where I work, there is an outbuilding where I can put my bike. Great. We could put sockets out there. But I'd have to buy another charger - or carry mine back and forth.

We actually have lots and lots of visitors - quite a few are cyclists. It would be great to offer charging facilities to all of them. Without having to keep the full gamut of charger specifications. Can imagine one day we'd have a fleet of Bosch ebikes; next day Woosh! Or Giant. So even one of each wouldn't actually cover all needs.

USB charging has been a huge convenience for all manner of items. I'd like to see that convenience extended to ebikes. Might not be quite there, but there is the high power USB Power Delivery (PD) spec. - which could be close to useful provided the ebike could accept 12 or 20 V and do whatever it needs with that.
 

Gubbins

Esteemed Pedelecer

Woosh

Trade Member
May 19, 2012
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Southend on Sea
wooshbikes.co.uk
We actually have lots and lots of visitors - quite a few are cyclists. It would be great to offer charging facilities to all of them.
wireless charging is a great way to provide free electricity to commuters. There is no direct contact with the customers' bikes, all the charger has to do is to identify the receiving circuit and start pumping magnetic juice until the receiver says enough...
 

mike killay

Esteemed Pedelecer
Feb 17, 2011
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Not sockets, pads, plated metal that doesn't corrode like those on the Lafree series I mentioned. Fixed on the bike, lightly sprung on the charge base to ensure firm contact when against each other. Been working on those bikes with up to 15 amps since 2001, so e-bike charge current no possible problem.

I'm just not a sucker for all the unnecessary complexity being designed in far too often now, I'm sure you know the US acronym, KISS.
.
As a certain Mr Twain remarked,
'What you ain't got don't need no fixin'.
 
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oyster

Esteemed Pedelecer
Nov 7, 2017
10,422
14,609
West West Wales
wireless charging is a great way to provide free electricity to commuters. There is no direct contact with the customers' bikes, all the charger has to do is to identify the receiving circuit and start pumping magnetic juice until the receiver says enough...
More a case of "could be" than "is", don't you think?

Time from now to widespread wireless is going to be many years. I reckon that a simple universal connection might be achievable in a much shorter period. If, as I half-suggested, there was an adaptor that I could fit to my bike which would make it compatible with a universal spec. supply, that was light, easy to carry/fix, and inexpensive, we could get a lot of the benefits sooner.

While my workplace would be willing to invest something, I can't seem them paying out for a full rack-with-wireless-charging. I also have this funny idea that, just as with ordinary racks, many would not take 2.6" or other fatter tyres.
 

Woosh

Trade Member
May 19, 2012
20,370
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Southend on Sea
wooshbikes.co.uk
More a case of "could be" than "is", don't you think?

Time from now to widespread wireless is going to be many years.
It's really not very difficult to make.

https://cyclingindustry.news/wireless-charging-for-electric-bikes-on-the-horizon/

“At present the component part for the bicycle measures at about 20cm in length, but I anticipate that this will get smaller. Once aligned, the battery will charge at much the same rate as it would when plugged in by cable,” David told CI.N. “I think this is the perfect solution for electric bike rental fleets. I envisage this also out the front of rows of shops or by transport hubs.”
how it looks:



here is another one:
https://electricbikereport.com/ebike-news-high-tech-lavelle-new-evelos-wireless-charging-mobile-library-more-videos/