Before I buy the following item can anyone spot a gaping flaw in my plan:

1. Exposure Revo/SP8 Hub (already got)

2. With this plumbed into the adaptor plug as well as the Revo light:
http://www.wheelies.co.uk/p64083/Biolog ... wwoddicAiw

3. Then in turn its micro-usb plugged into this (confirmed as able to be charged while supplying power):
http://www.bmstores.co.uk/products/opti ... ank-287363

4.Full size usb port then supplying a constant charge to phone/garmin/etc.

Getting usb DC out for £30, seems too good to be true (admittedly the device doesn't look the neatest set-up!)?

No flaws, it will work. Nice cheap set up. Can't see any spec for what current the charging device is limited to, (or on manufacturers site) probably 500ma which is ok.
Personally I'd stump up a little bit more and go for a 4500 to 5000mahr battery to give you more charging versatility off bike. But on bike supply and charging will be fine with what you have.

It might be worth checking out some of the Anker power packs.
The one I just bought has two outputs, one at 2amp and the other at 1amp. So can charge 2 things at once and likely at 2x and 4x faster than the one you are looking at (assuming num is correct that it only has a 0.5amp output).

The anker one is 80% efficient which is actually pretty good for batteries, some of them have 70% efficiency or less for cheap battery cells. So for your 2500mah battery you should not expect to get anymore than 1700mah of charging out of it. Not really a problem if you are using it purely as an on bike buffer but if you want to use it off bike that would not fully charge a single AA battery or most modern smart phones.

Of course, if the capacity is a problem you can always buy a larger battery from any brand but it is worth factoring in that you will never get out what is claimed on the battery.

Looking at the biologic site I think it said max 850mah. I probably will opt for the battery you've got at some point, if only for the cable as you said. I've got the pack linked above and it'll do for now. I've got a 5000mah pack but its got a daft proprietary charging cable and I bet a fix costs more than your pack did.

Could you link to the Anker pack? Assuming you've tested that it charges/discharges simultaneously? I've got one of their 2 x 2A car chargers and it's great.

I have an Anker pack, with twin output, it can charge and discharge simultaneously.

Is that the Anker 3E?

No I have the E4 (13000mAh). It's a brick.

I have the Astro E5 (15000mah) - http://www.amazon.co.uk/15000mAh-Portab ... r+astro+e5

Again it can charge and discharge at the same time.

Not the most dainty but not too bad at just over 300g.

It did get me to thinking that maybe I dont need the dynamo at all if I have one of these. It can charge my phone from full to empty around 6 times or run a USB bike headlight for around 10 hours.

Should be enough to charge phone, AA batteries for GPS and run a light for a two to three day trip easily (unless you cycle in the dark a lot, which I dont).

And it fits nicely on my top tube in a tribag :)

I've got to say that so long as its protection circuitry is working properly, that little device looks like a right bargain and makes DIY options a lot less attractive.

Most of the cheaper USB battery packs don't allow you to charge / discharge at the same time, but these certainly do:

http://amzn.to/1srjuuB

I've got one of their larger A5 packs (currently not available) and it's fantastic.

The 500ma comment was referring to the output from the convertor you linked to. It was only a guess but it could be a factor depending on how far you ride.
Eg it would take 5 hours of riding to charge your 2500ma battery pack from flat.

Like you say if your not riding for multidays or long periods at night, why bother. A good battery pack and a non dynamo light would cover you.

A couple of potentially useful links I found while looking up options for my road-trippers dynamo to USB set-up.

http://cyclingabout.com/index.php/2012/ ... b-devices/ - the Lightcharge looks good (edit, no over-charge / DH speed protection though unf)

http://www.pokingthingswithsticks.com/p ... -charging/ - follow the pages via links on the RHS, a lot to go through but some good info there - unf. the MYOG battery charger result is a bit bulky.

But - is this really all you need to regulate the power from a dynamo to make a 5v USB connection work, like a Plug, or is it simply a battery output regulator that won't handle a dynamo at 30mph+?
http://www.pokingthingswithsticks.com/p ... ry-output/
If it'll fit into a steerer and work w/o a battery it could be part of the MYOG answer to what I'm after.

I liked the look of the light charge but someone here pointed out it only put out 350mAh.

250 apparently, so slower charging right? And no protection against high speed outputs.There is this available http://www.amazon.com/LightCharge-OPS-O ... NZZN4Z5YSN but it's not as neat as a Plug or Sinewave box.

250? That'll be slooooow!

jameso wrote:250 apparently, so slower charging right? And no protection against high speed outputs.There is this available http://www.amazon.com/LightCharge-OPS-O ... NZZN4Z5YSN but it's not as neat as a Plug or Sinewave box.

The doofer I linked to does the regulation & 5v output in one. I bought mine from Tredz as you get a fiver off £30 by subscribing to their news letter so 25 quid for the device and a couple of bottles of chain lube to take it up to £30. :)

Has anyone tried one of these yet?

http://www.bike-discount.de/en/buy/lumo ... ountry=190

A German bike tourist stayed with us a week or so back. He had one, the light was easily as bright as my Schmidt Edelux, it had a USB output and cache battery.

I'm tempted to give one a try.

mcmoonter wrote:Has anyone tried one of these yet?

http://www.bike-discount.de/en/buy/lumo ... ountry=190

A German bike tourist stayed with us a week or so back. He had one, the light was easily as bright as my Schmidt Edelux, it had a USB output and cache battery.

I'm tempted to give one a try.

I had the Edelux II down as the front light choice but a combined USB and battery is a great idea, hadn't seen this light until I found that list / link I posted last night. I like the idea of locating all the stuff a bit lower down and the remote bar switch is a bonus. http://www.thorncycles.co.uk/forums/ind ... pic=4557.0 some more info on it here - inc a beam pattern shot here that looks very good http://www.bumm.de/innovation-original/ ... erfer.html

mcmoonter wrote:Has anyone tried one of these yet?

http://www.bike-discount.de/en/buy/lumo ... ountry=190

A German bike tourist stayed with us a week or so back. He had one, the light was easily as bright as my Schmidt Edelux, it had a USB output and cache battery.

I'm tempted to give one a try.

I could not see its output on that page but I am sure on Rosebikes it quotes upto a 1A output which is pretty decent.

There is also this one which is cheaper and has a 500mah output.....

http://www.rosebikes.co.uk/article/axa- ... aid:642351

johnnystorm wrote:

jameso wrote:250 apparently, so slower charging right? And no protection against high speed outputs.There is this available http://www.amazon.com/LightCharge-OPS-O ... NZZN4Z5YSN but it's not as neat as a Plug or Sinewave box.

The doofer I linked to does the regulation & 5v output in one. I bought mine from Tredz as you get a fiver off £30 by subscribing to their news letter so 25 quid for the device and a couple of bottles of chain lube to take it up to £30. :)

That's the remote box to go for then, I was just taken by the smaller size of the Lightcharge. I guess it's easy enough to re-wire with longer leads so that it can be put in a bar roll / bag etc?

http://yacf.co.uk/forum/index.php?topic ... 583.165%29

? Some comments here suggest the Dahon unit may be ok at off-road speeds but less so on Alpine roads.

jameso wrote:http://yacf.co.uk/forum/index.php?topic ... 583.165%29

? Some comments here suggest the Dahon unit may be ok at off-road speeds but less so on Alpine roads.

Looks like adding an inline switch might be an idea for long daytime descents, alas I don't think there's going to be much call for that from me. It also seemed that if you were charging a battery that would take some of the load off, I'd leave my battery pack/phone/gps connected all the time needing charge. At night the inline switch might be nice if the gadget charging takes way from the revo light output. It's never simple......

jameso wrote:But - is this really all you need to regulate the power from a dynamo to make a 5v USB connection work, like a Plug, or is it simply a battery output regulator that won't handle a dynamo at 30mph+?
http://www.pokingthingswithsticks.com/p ... ry-output/
If it'll fit into a steerer and work w/o a battery it could be part of the MYOG answer to what I'm after.

The issue is more subtle than it appears, and it's taken me a while to get to the bottom of why so many of these regulator units appear to be quite fragile, electrically at least.

Many modern 5v regulators will handle input voltages of typically 7-36v which will cause no issue from a rectified dynamo output while there is a load on the regulator. The problem comes when the device is fully charged and the regulator is no longer pulling power from the dynamo. In these circumstances, the regulator presents a very high resistance to the dynamo, and the voltage across the dynamo can reach much more than the maximum input voltage of the regulator (and indeed the smoothing capacitors). Fried components can easily result.

A protection circuit is therefore needed, see my comments and links here:

http://forum.ctc.org.uk/viewtopic.php?f ... 41#p777550

So run the lights all the time then?

Lughnasadh wrote:I have the Astro E5 (15000mah) - http://www.amazon.co.uk/15000mAh-Portab ... r+astro+e5

Again it can charge and discharge at the same time.

Not the most dainty but not too bad at just over 300g.

It did get me to thinking that maybe I dont need the dynamo at all if I have one of these. It can charge my phone from full to empty around 6 times or run a USB bike headlight for around 10 hours.

Should be enough to charge phone, AA batteries for GPS and run a light for a two to three day trip easily (unless you cycle in the dark a lot, which I dont).

And it fits nicely on my top tube in a tribag :)

Wow, great price, it just arrived
Charges my Note2 quickly

Thanks for the pointer