Dynamo usb

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Adventure56
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Dynamo usb

Postby Adventure56 » 5 Feb 2019, 10:59am

Can anyone recommend a Dynamo usb for charging iPad and phones etc.

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SimonCelsa
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Re: Dynamo usb

Postby SimonCelsa » 5 Feb 2019, 11:47am

I've been using the AXA Luxx 50 for the past couple of years. It has been very reliable as a front light & has always performed well when I have needed the USB port to recharge my cellphone (which is not that often). The only downside is that you can't use the light & recharge simultaneously.

I don't think they sell this one anymore but the Luxx 70 looks fairly similar & no doubt brighter.

https://www.rosebikes.co.uk/axa-luxx-70 ... ght-642349

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[XAP]Bob
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Re: Dynamo usb

Postby [XAP]Bob » 5 Feb 2019, 1:19pm

BioLogic ReeCharge has been my USB provider for a while.
A shortcut has to be a challenge, otherwise it would just be the way. No situation is so dire that panic cannot make it worse.
There are two kinds of people in this world: those can extrapolate from incomplete data.

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andrew_s
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Re: Dynamo usb

Postby andrew_s » 5 Feb 2019, 1:59pm

What's best depends on what you want to supply power to, and how it reacts if you stop at the traffic lights and the USB power stops, or you start slowly.

Garmins, for example, come up with a screen prompt "External power lost - continue on battery?", and if you don't poke the "Yes" button within 30 secs or so, they turn off.
Other devices may switch silently on battery, and resume using external USB power when the lights change, and others may switch to battery and continue on battery unless you pull out the lead and plug it back in.
To avoid this, some USB chargers have a small battery built in to cover short stops.

Another problem is that many devices, because they may be plugged in to the USB port of an old laptop running on battery rather than a mains charger, will try out how much current they can take before the voltage starts to drop, and settle on that current thereafter. With a bike USB charger, they may do that before you've got properly moving, and settle on a low charge rate even though the hub will give plenty more when you are moving. Some devices (eg Sinewave, Igaro) have a delay before they give any power, to give you a chance to get going first.

You can get an idea of some things by using a mains USB supply, and seeing how your device reacts if you turn the socket off and back on. There are also inline meters you can get to investigate the supplied current.

Such problems mean that it is often better to charge via a USB power pack that supports pass-through charging (i.e.it can be charged at the same time as it's supplying power to something else), despite the loss of efficiency that the extra voltage conversion steps cause. I use a Zendure A2.

HobbesOnTour
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Re: Dynamo usb

Postby HobbesOnTour » 6 Feb 2019, 11:23am

andrew_s wrote:What's best depends on what you want to supply power to, and how it reacts if you stop at the traffic lights and the USB power stops, or you start slowly...........


That's an excellent post!
Doesn't help you with a recommendation, though :D

A search on these and other forums will turn up a lot of information. There have been a lot of developments in this area in the 4 years or so since I did my research.

I settled on a Cycle2Charge unit because it was discreet, simple and relatively cheap. I use it for touring and find it very effective. I aim for a minimum speed of 13 kph for charging (26 inch wheels), although it will kick in below that.

As andrew_s suggests, I charge a battery pack from my usb unit and then charge my devices from that - the only exception being my Wahoo gps device which will run and charge directly from my dynamo. The battery pack sits in my handlebar bag so is not attached to the bike.
An advantage of a separate battery pack is that you can charge it from the mains when you have the chance.

Bez
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Re: Dynamo usb

Postby Bez » 6 Feb 2019, 12:43pm

andrew_s wrote:Garmins, for example, come up with a screen prompt "External power lost - continue on battery?", and if you don't poke the "Yes" button within 30 secs or so, they turn off.


You can switch that "feature" off in the settings (or at least you can on every Garmin I've tried to charge on the fly—maybe there are some where that's not the case). That said, Garmins don't like fluctuating charge IME and start to do bizarre things.

andrew_s wrote:Such problems mean that it is often better to charge via a USB power pack that supports pass-through charging (i.e.it can be charged at the same time as it's supplying power to something else), despite the loss of efficiency that the extra voltage conversion steps cause. I use a Zendure A2.


I've come to a broadly similar conclusion: after trying a couple of dynamo chargers I've decided I'm better off using a separate battery to charge devices, and then using the dynamo to charge the battery if needed. (Which for me it rarely is—but then I don't tour in the back of beyond.)

eg https://twitter.com/mashing53/status/10 ... 0344624128

Image

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Audax67
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Re: Dynamo usb

Postby Audax67 » 6 Feb 2019, 1:12pm

I use a B&M eWerk with a buffer battery, normally to run lights + GPS but it could probably take another tap to charge a phone as well.
Have we got time for another cuppa?

Samuel D
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Re: Dynamo usb

Postby Samuel D » 6 Feb 2019, 1:17pm

Bez wrote:Image

I spy an Anker PowerCore+ Mini! I have one too. The small, volume-efficient design, metal housing, and Panasonic cells made it attractive to me. Another benefit is being able to charge another device at under 50 mA (useful for some power meters, sports watches, and other gadgets with tiny batteries). Not all powerbank support such low currents.

Charging anything on the move runs into the problem of vibrating cables eventually damaging the USB ports, plus the practical impossibility of waterproofing any of the gadgets. That’s another reason to charge a cheap powerbank rather than an expensive phone or GPS unit directly.

Bez
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Re: Dynamo usb

Postby Bez » 6 Feb 2019, 1:39pm

It's an Anker Walkpower; probably an older model of the same thing. Anker seem to produce pretty reliable stuff. The cigar-shaped ones are just quite handy for attaching to things (this one's attached by way of a Zefal pump holder, I think).

I've got another (non-Anker) one which has an integrated LED in the other end, which makes for a bit of backup.

In particular, the Anker batteries (and presumably many others) are a smidge over 22mm in diameter, which means you can use them to replace the bar in extension brackets such as the one below, and if need be you can then attach a device to it. It also means you can in theory waterproof it (when not plugged in) by cutting the end off of an MTB grip and slipping that over the open end.

Image

To be honest I'm not convinced vibration is a problem in most cases; or at least, its effects can be eliminated through choice of cables and positioning—but I guess it may be if you have any devices with particularly un-grippy Micro sockets or where the cables necessarily end up pressed against a part of the bike.

CyclingGuy
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Re: Charging my phone whilst riding

Postby CyclingGuy » 7 Feb 2019, 10:40pm

The outstanding product has to be the unit from Busch & Muller here - https://amzn.to/2UT4RnJ. Not exactly cheap but very good.

Alternatively the Kemo M-172N https://amzn.to/2HZfcNh is an OK unit but not quite as good, hence the cheaper price.

HTH

Neil
Read about my adventures on the British Cycle Quest at: http://www.quest.nwarwick.co.uk

Norman H
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Re: Dynamo usb

Postby Norman H » 8 Feb 2019, 12:11pm

I agree with what others have said about the idiosyncrasies of charging. Using a cache battery is often the simplest solution.

I've got an Axa Luxx 70 plus light which has bult in charging. Its maximum output is limited to 500ma and it wont charge and power lights at the same time. It's been ultra reliable over several years.

I've also got other bikes with dynamo lighting and have recently been looking to buy a Cycle-2-Charge V2.

There's a review here

Unfortunately it doesn't seem to be available direct from the manufacturer, or from Amazon UK, at the moment.

It still seems to be available from Amazon Germany
Last edited by Norman H on 8 Feb 2019, 6:19pm, edited 1 time in total.

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andrew_s
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Re: Dynamo usb

Postby andrew_s » 8 Feb 2019, 4:53pm

An example of charging idiosyncrasies is the B+M Luxos U.

It's got an internal buffer battery to protect against loss of power at short stops, which is good, but the other thing it does is to boost the available power if you are going too slowly to generate the power required by what's connected.
This is also good, on the face of it, but if extra power from the buffer battery is required for too long, the battery runs out. At that point, all available power goes to recharge the buffer, and none goes to your connected device. So, for example, if you are using a front light and powering a Garmin, you may find that, by the time you get to the top of a long hill, the Garmin has turned itself off.

LittleGreyCat
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Re: Dynamo usb

Postby LittleGreyCat » 10 Feb 2019, 1:23pm

[XAP]Bob wrote:BioLogic ReeCharge has been my USB provider for a while.


Just looked for this, and both Amazon and Evans no longer seem to stock it. Possibly no other BioLogic kit either.

Any recommendations for a similar add on?

Edit: Cycle2Charge seems to have gone walkabout as well. Something funny going on in the supply chain? Perhaps a reluctance to order if you don't know the import duty at time of shipping?

Norman H
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Re: Dynamo usb

Postby Norman H » 11 Feb 2019, 7:47am

The Cycle-2-Charge V2 appears to have been replaced by by Cycle-2-charge V3

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Sweep
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Re: Dynamo usb

Postby Sweep » 11 Feb 2019, 9:22am

Norman H wrote:The Cycle-2-Charge V2 appears to have been replaced by by Cycle-2-charge V3


Thanks for that.
After a lot if thought I gave up on the idea of bike power generation in favour of just charging a small array of powerbanks from available mains supplies.

But I remain interested in that device because of hobbesontour's positive feedback.

A!though I value simplicity/lack of hype, I must admit though to being discouraged by the basic nature of that web page. It doesn't even say what the difference is between version 2 and 3 and all the stats are still for version 2.
Sweep