Charging a high capacity battery from a dynamo?

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tommydog
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Re: Charging a high capacity battery from a dynamo?

Post by tommydog »

DarkNewt wrote:
on a separate note I have a biologic reecharge to giveaway for free, I have offered it twice but no one wants to pay for postage lol!!! I also have the cache battery from an e-werk free to a good home just be nice and cover the postage!
Newt!


That's a very generous offer - PM sent :D
DarkNewt
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Re: Charging a high capacity battery from a dynamo?

Post by DarkNewt »

Hi no pm recieved? Not generous I believe in recycling and helping out others the way I have been helped, I would rather it went to a cyclist that will use it. BTW the biologic comes with a built in cache battery, I just couldn't get on with it as the indicator lights were too dim for me and couldn't tell half the time if it was on but others like it? If your near me I have other bike stuff you can pick up.
Currently planning my next adventure and trying to get over two operations in 6 months but still going strong!
email: newt@systems-engineer.info web: thedarknewt.blogspot.co.uk
tommydog
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Re: Charging a high capacity battery from a dynamo?

Post by tommydog »

ConRAD wrote:Looking now to the first one, as you can see it ideally seems to require something around 5V-2A ... that meaning something around 10W !!
Since I know very well that from an e-werk (or things alike) youl'll never get more that 3W at 20km/h, the immediate consequence if you decide to connect an Anker 20100 to an e-werk will be its immediate voltage drop to the point that the charging process will never start.
Based on my experience many devices supposed to be charged via 5V-usb will never charge once the voltage drops below 4.75V.
So for your Anker you must keep relying on pubs or on hidden mains often available in real unsuspectable corners.

Image



Did you see DarkNewt reply below, which contrasts with your information. He seems to be Charging a Rav Power 26000Mah battery from the dynamo as a workable solution. In light of this I think the figures you quote must reflect maximum charge specification and not minimum.

Following DarkNewt's experience I am very temped to pick up a Rav Power 26000 as shown here:

https://www.amazon.com/dp/B012NIQG5E

Also as a lower capacity option the Lizard 50 (13800mAh) looks like it may work
http://www.tregoo.com/lizard-50-en.html


DarkNewt wrote:
I have been doing this for a while now, my setup is Shimano dynamo - which is routed into an Ortlieb 6 E bag (the wiring is built into the mount). this is then wired into busch & muller e-werk which is in turn wired into a Rav Power 26000 Mah battery both stored and protected withing the Ortlieb E bag.

Some points: the RAV power supports passthrough charging, so with this setup I am constantly charging the batter and at the same time the outputs are plugged into my Sat Nav and Camera.

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Sweep
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Re: Charging a high capacity battery from a dynamo?

Post by Sweep »

Thanks for your post above darknewt.

Interesting that, if I have read things right, you don't use dynamo powered lights at all.
Sweep
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ConRAD
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Re: Charging a high capacity battery from a dynamo?

Post by ConRAD »

1. As I can see the "pass-through" option appears to be quite a controversial issue, to the point that the official opinion of an Anker engineer (competitor of RAV) is the following:
quote
we actually made the decision to remove this function from our portable chargers. When pass-through charging, if there is a difference between the output of the wall charger and the input of the device being recharged it can cause the portable charger to rapidly power on and off. This increases charging times for both the portable charger and your device, risks causing damage to the battery cells and can significantly shorten the portable charger's lifespan
unquote
2.: I also add that in the case the pass-thru option shouldn't be properly designed there's the real risk to pass to the output the same voltage instability that you might have at the input when supplying the power-bank not from a stable 5V-usb power suply but from an AC/DC dynamo converter
3.: These types of power-banks are indeed all designed to be charged via 5V-usb wall chargers and not via e-werk or things alike. Please don't forget that if you use an e-werk you have the chance to select the voltage output between 4.9V (too low) and 5.6V (too high)
4.: furthermore I can see that there is a big "misunderstanding" between the terms "charging" and "topping-up". If you leave home with a power-pack already charged it means that you are quite likely passing power to the devices connected and not to the power pack, i.e. in this case you are topping-up and not charging
5.: last point, the capacity of a battery must be expressed in terms of mAh, its energy in Wh or mWh
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tommydog
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Re: Charging a high capacity battery from a dynamo?

Post by tommydog »

ConRAD wrote:
tommydog wrote:... did you glue or bolt things in place? Also what material did you use for it?

3mm angular/plain PVC sheet from local Brico, cut and glued only (definitely very strong)


Thanks for that info. when you say glue, do you mean you used something like PVC Pipe Cement like this:
https://www.amazon.co.uk/Everbuild-P16P ... ms?ie=UTF8

That's the only type of stuff I have found any good on plastic.

Also from your website pictures I see you have a red box mounted in the compartment. Is that secured by cable ties as I can't quite see how it is fixed?
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mjr
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Re: Charging a high capacity battery from a dynamo?

Post by mjr »

ConRAD wrote:3.: These types of power-banks are indeed all designed to be charged via 5V-usb wall chargers and not via e-werk or things alike. Please don't forget that if you use an e-werk you have the chance to select the voltage output between 4.9V (too low) and 5.6V (too high)

This makes me wonder if a Li-Ion batter in my little Soshine charger would be a better option than a usual USB pack. The Soshine charger accepts a wide voltage range (up to 12v I think) - the main disadvantage would be it potentially rebooting and redoing its battery type detection after each stop. I don't know if it can ride out short stops. Maybe something I'll test once I wire the USB charger into the dynamo, probably during spring service in a few weeks.
MJR, mostly pedalling 3-speed roadsters. KL+West Norfolk BUG incl social easy rides http://www.klwnbug.co.uk
All the above is CC-By-SA and no other implied copyright license to Cycle magazine.
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mjr
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Re: Charging a high capacity battery from a dynamo?

Post by mjr »

Sweep wrote:Unless someone manages to convincingly contradict you, yes, to my non techie mind, a large capacity battery appears to be better,

Completely non techie reason: larger capacity batteries tend to be heavier. Maybe not enough that you care, but it's one contradicting reason.
MJR, mostly pedalling 3-speed roadsters. KL+West Norfolk BUG incl social easy rides http://www.klwnbug.co.uk
All the above is CC-By-SA and no other implied copyright license to Cycle magazine.
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ConRAD
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Re: Charging a high capacity battery from a dynamo?

Post by ConRAD »

tommydog wrote:... when you say glue ...

.. when I say glue I say that fantastic 2 euro tube that I bought at Brico; the label is in Italian (at least in my case) ... the content is of course chinese and says: "ideal for PMMA, PS, ABS, PVC, .. etc" ... and the result is that once glued you can't destroy it anymore !!!

tommydog wrote:... I see you have a red box mounted in the compartment ...

... it's a Hama USB-hub, one 5Vdc input - four 5Vdc outputs
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tommydog
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Re: Charging a high capacity battery from a dynamo?

Post by tommydog »

ConRAD wrote:... it's a Hama USB-hub, one 5Vdc input - four 5Vdc outputs


Thanks for clearing this up, I could not make it out from the picture.

Just one other thing - Is it a wire bracket you made to mound this or is it a cable tie I can see?
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ConRAD
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Re: Charging a high capacity battery from a dynamo?

Post by ConRAD »

tommydog wrote:.. is it a cable tie I can see?

yes
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tommydog
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Re: Charging a high capacity battery from a dynamo?

Post by tommydog »

ConRAD wrote:1. As I can see the "pass-through" option appears to be quite a controversial issue, to the point that the official opinion of an Anker engineer (competitor of RAV) is the following:
quote
we actually made the decision to remove this function from our portable chargers. When pass-through charging, if there is a difference between the output of the wall charger and the input of the device being recharged it can cause the portable charger to rapidly power on and off. This increases charging times for both the portable charger and your device, risks causing damage to the battery cells and can significantly shorten the portable charger's lifespan
unquote
2.: I also add that in the case the pass-thru option shouldn't be properly designed there's the real risk to pass to the output the same voltage instability that you might have at the input when supplying the power-bank not from a stable 5V-usb power suply but from an AC/DC dynamo converter
3.: These types of power-banks are indeed all designed to be charged via 5V-usb wall chargers and not via e-werk or things alike. Please don't forget that if you use an e-werk you have the chance to select the voltage output between 4.9V (too low) and 5.6V (too high)


I hear what you say, but my point is a user on this forum has reported success with charging the 26800mAh RAV battery. I know you mention the 4.9v and 5.6v of the e-werk, but why not get something that puts out 5v exactly? Just logically I would have thought there was an element of protection in these power packs, as there may well be variation in many 5v wall chargers. I remember seeing a website a while ago where they tested the voltage from a number of wall chargers, and very few were putting out a constant stable 5v. Apple was the notable exception.

As for the pass through issue, is pass through such an important feature? Why not charge your devices when sleeping at night. That way you always have devices with plenty of power of the morning.
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Sweep
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Re: Charging a high capacity battery from a dynamo?

Post by Sweep »

Yes, I'm hovering on the edge of mobile power generation and storage but pass through doesn't seem like a mega requirement for me either. If I reached the slightly extreme pass of needing a powerbank and an in use device requiring charging at the same time I think I would go sit in a bar for two hours, people watch etc.
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ConRAD
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Re: Charging a high capacity battery from a dynamo?

Post by ConRAD »

tommydog wrote:... but my point is a user on this forum has reported success with charging the 26800mAh RAV battery ...

... actually he didn'd say at all "charging" but " ... "I start off with a 26000 Mah battery fully charged" ... that's a different story isn't it ??
However, just in case you eventually decide for buying one, let me know about your conclusions, thank you.
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Sweep
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Re: Charging a high capacity battery from a dynamo?

Post by Sweep »

sorry Conrad - I don't really understand your point.

I assume he meant putting charge into the battery.

Whether he ever achieved full charge from a starting position of zero (and let's face it to set off with a powerbank you hadn't pre-charged from mains power would be perversity/puritanism of the most extreme kind) doesn't seem to really matter - the whole point surely is to be able to use the powerbank to recharge stuff as you go, not to wave it' fully charged status around as a totem? And never extract owt from it.

Apologies if I have missed something.
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