# Dynohub Free charger.



## Tombo 707 (9 Sep 2009)

There is a batterry charger for the Dynohub, people out there that want to harness there power and use it to charge u.s.b gadgets. Its been a long time coming. The Biological Free charger by Dahon who make folding bikes. On the market March 2010. Iuse a solar freeloader at the moment but I think with a Dynohub and being able to charge stuff on the move this ones a winner.


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## Joe24 (10 Sep 2009)

Or just make up a USB charger thing like this?
http://geektechnique.org/projectlab/511
Could easily add on a different connection instead to use to charge up whatever you have.


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## Tombo 707 (10 Sep 2009)

Too many wires. Looks to much Tallybannish to me.


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## Joe24 (10 Sep 2009)

Tombo 707 said:


> Too many wires. Looks to much Tallybannish to me.



Well, it would be pretty simple to make it look neat wouldn't it? And wouldn't cost as much as a stupid Freeloader, they were just under £30 at work when we had them in, this new one will probably be about the same, or maybe more.


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## Tombo 707 (10 Sep 2009)

I wish I had the skills to make one. I was just saying there is a big interest in taking power from your dynohub. There should have been something on the market by now. Regards Tom


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## andrew_s (11 Sep 2009)

Like buses...
there's the Dahon, and
http://www.bumm.de/index-e.html?docu/361e.htm
http://www.pedalpower.com.au/index.htm


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## Davidc (11 Sep 2009)

One wire, 2 diodes, a car 12v socket, 10 NiMH batteries, a box to mount them in and with things own car charger leads you can recharge anything!

If anyone's interested I'll draw and scan the circuit.

Only drawback - both the positive and negative connections are live to the bike frame.

Edit: Total cost about £5


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## just jim (11 Sep 2009)

Tombo 707 said:


> I wish I had the skills to make one. I was just saying there is a big interest in taking power from your dynohub. There should have been something on the market by now. Regards Tom




There will be.


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## yello (15 Sep 2009)

andrew_s said:


> http://www.bumm.de/index-e.html?docu/361e.htm



The E-Werk was at the Eurobike show and will be available next month. It looks like a top bit of kit but at €139, I think I'll be assessing other options!


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## Joe24 (15 Sep 2009)

I should have a dynamo come sometime soon, weds/thurs, and i think im gonna have a play with that, and try and make up a charger with it, if i can, and hopefully have it so i can plug something into something on the dynamo, so its not on when i dont need it, if you get me.
Will have to see how it goes though, doesnt look too hard ....................


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## andym (20 Sep 2009)

These guys look like a good option. :

http://www.pedalpower.com.au/

They offer either a hub dynamo or a bottle dynamo (if you already have a hub dynamo then the B&M looks like the one to go for). When I contacted them earlier this year they said they could ship to the UK for $39 (US).

Good luck Joe. I must admit I'd like to have a quid for every post I've seen from people saying how easy it would be to make a gizmo to convert the output from a dynamo.


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## oxford_guy (23 Sep 2009)

andrew_s said:


> Like buses...
> there's the Dahon, and
> http://www.bumm.de/index-e.html?docu/361e.htm
> http://www.pedalpower.com.au/index.htm



I'm really interested in a dynohub charging solution to recharge my GPS etc. on long tours. One solution that wasn't mentioned was is the ZZing, which is cheaper than the B&M solution (which I wasn't aware of), though doesn't look as sophisticated. I'd be very interested to see how much the Dahon device will be and whether its a serious competitor to the other products mentioned.

I have a Schmidt SON 28 dynamo, which should be up to the job of providing power...


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## bike_the_planet (27 Sep 2009)

Davidc said:


> One wire, 2 diodes, a car 12v socket, 10 NiMH batteries, a box to mount them in and with things own car charger leads you can recharge anything!
> 
> If anyone's interested I'll draw and scan the circuit.
> 
> ...



Sorry - you'll need more than that. For a start, NiMh batteries have trickle and peak charge current limits. If you exceed those then you risk gassing the cells rendering them unuseable. At the very least you'll need a couple of resistors to limit that current. 

However, a simple resistor plus diode is not very efficient, because at low wheel speeds you'll reduce the charging current and therefore the energy you're putting into the cells. You really need a regulator that maintains the max trickle current (normally C/20 for NiMh) regardless of dynamo output voltage to maximise the energy transfer to the batteries.

Also, to make a comprehensive charger you really need multiple output voltages: 5vdc for USB devices; 12 v for phones and cameras.

Cheers,

Tony


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## Davidc (27 Sep 2009)

bike_the_planet said:


> Sorry - you'll need more than that. For a start, NiMh batteries have trickle and peak charge current limits. If you exceed those then you risk gassing the cells rendering them unuseable. At the very least you'll need a couple of resistors to limit that current.
> 
> However, a simple resistor plus diode is not very efficient, because at low wheel speeds you'll reduce the charging current and therefore the energy you're putting into the cells. You really need a regulator that maintains the max trickle current (normally C/20 for NiMh) regardless of dynamo output voltage to maximise the energy transfer to the batteries.
> 
> ...



The circuit I used is 2 1/2 wave rectifiers charging a positive and separate negative set of NiMH cells. The mean current from the dynamo when running is 1/2 amp, 1/4 amp on each polarity cell set, and a bike dynamo is close to a constant current source.

The NiMH batteries used were RC spec, manufacturers figures were 3500 mAH capacity at 3.5A discharge, max continuous charge 400mA mean, 24A max peak current charge or discharge. (Roughly the size of C cells)

There is no need for any resistor in series. A hub dynamo can't produce an output exceeding these limits. Output being taken while charging needs to be deducted, and until the cells are fully charged they'll put up with almost anything (<24A)

I had silicon 'self resetting fuses' in series with the charging lead and both poles of the 12v output. NiMH batteries can discharge at very high currents, and both + and - of the 12v are live to the bike frame!

It's crude, but worked well for two 2 week tours, charging all of the party's mobile phones using a Nokia car charger (gives the 3.5v supply from a SMPS in the plug), and running several other bits of kit at the camp sites, keeping us self sufficient for power. In practice its unlikely that the batteries were ever fully charged, but we never ran out either.

(I still have the charger, somewhere in with the camping kit in the loft, and the batteries were last seen powering a boat.)


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## andym (1 Oct 2009)

I've just received the pedalpower universal cable plus bits and pieces. First impressions are that it looks like a polished and professional product. The electronics are in a full-sealed plastic case that's about 75mm long and 15mm square at its widest point. I also bought a charger and a set of accessory tips: although the tips seem to be compatible with the interchangeable tips used by the powerchimp and some other travel charger products.

Only downside was the delivery charge of 49 Australian dollars - but that was for delivery by UPS who were fast - but expensive.

I'll post again wen I've had a chance to give it a good test - not sure when that will be.


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## oxford_guy (1 Oct 2009)

andym said:


> I've just received the pedalpower universal cable plus bits and pieces. First impressions are that it looks like a polished and professional product. The electronics are in a full-sealed plastic case that's about 75mm long and 15mm square at its widest point. I also bought a charger and a set of accessory tips: although the tips seem to be compatible with the interchangeable tips used by the powerchimp and some other travel charger products.
> 
> Only downside was the delivery charge of 49 Australian dollars - but that was for delivery by UPS who were fast - but expensive.
> 
> I'll post again wen I've had a chance to give it a good test - not sure when that will be.



Thanks for the info., would be very interested to hear of your experiences with this. A few questions:

* does the unit look waterproof?
* what hub dynamo are you using? Schmidt, Shimano, something else?
* can you leave the dynamo lights permanently plugged into the dynamo or do you need to unplug them the run the Pedalpower?

NB: am assuming you cannot run dynamo lights and charge devices off the Pedalpower at the same time...

Thanks!


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## oxford_guy (1 Oct 2009)

Also, which battery charger version did you go for, I notice that they offer a number of different ones? Thanks


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## andym (2 Oct 2009)

oxford_guy said:


> Thanks for the info., would be very interested to hear of your experiences with this. A few questions:
> 
> * does the unit look waterproof?
> * what hub dynamo are you using? Schmidt, Shimano, something else?
> ...



Yes it does look waterproof. In fact the electronics look sealed into a one-piece moulding that you couldn't pull apart even if you wanted to.

I'm planning to use a Schmidt Dymotec bottle dynamo.

Sorry, I don't know whether you can plug lights into the lead itself, or connect both the lead and the lights to the dynamo. I would think that you could have both connected to the dynamo - but probably not use both at the same time. But you can always email Nicholas Kidd at pedalpower - I'm sure he'll know the answer.

I'm actually planning to use it with a PowerTraveller Powerchimp and 2800 NiMH rechargeables. The battery units from pedalpower have some neat features - eg you can use them to charge more than one device and I _think_ you can charge gizmos from them while recharging the battery) but at the end of the day, the powerchimp seemed like the simpler and cheaper solution (and I already have one!) - touch wood it works of course. 

On the subject of powertraveller, as I've just splashed out on a netbook and I'm seriously considering getting their Minigorilla battery unit - although I should say that I've don't know whether this would work with the dynamo - or whether the dynamo would provide enough power to make it worthwhile trying to use it to power a netbook on top of everything else!


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## andrew_s (3 Oct 2009)

The powerchimp is specified to charge its 1800mAh batteries in 5h, so your 2800mAh are going to need 7h50 or thereabouts of charging time. The pedalpower AA charger seems to charge at a similar rate, presumably because both are designed to charge from USB.
I'd reckon that would mean that about 40% of your riding time would be dedicated to keeping a GPS running. Add on phones, torches, MP3, and I doubt there'd be enough left over for a netbook.


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## andym (3 Oct 2009)

andrew_s said:


> The powerchimp is specified to charge its 1800mAh batteries in 5h, so your 2800mAh are going to need 7h50 or thereabouts of charging time. The pedalpower AA charger seems to charge at a similar rate, presumably because both are designed to charge from USB.
> I'd reckon that would mean that about 40% of your riding time would be dedicated to keeping a GPS running. Add on phones, torches, MP3, and I doubt there'd be enough left over for a netbook.



I had a feeling it wasn't a realistic prospect!


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## oxford_guy (7 Oct 2009)

*Case that will fit Garmin eTrex Vista HCx with bike mount adaptor?*

Hi - the standard Garmin case doesn't fit my eTrex Vista HCx GPS when the Garmin bike mount adaptor is attached, does anyone know of a suitable alternative case/bag that would fit it, so the GPS doesn't get knackered when kicking around in my bag off-bike?

NB: I tried the RAM bike mount to attach the eTrex Vista to my bike, which is very secure and doesn't require attaching an adaptor to the GPS unit, but the mount is _huge_, and draws lots of attention to the unit, so I've gone back to the Garmin mount, even though its crap and rattles, because it doesn't grip the eTrex very securely....


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## andym (8 Oct 2009)

It's waterproof - you don't need a case (although a piece of screen protector would definitely be a good idea).

PS you should have put this in a new thread.


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## oxford_guy (8 Oct 2009)

andym said:


> It's waterproof - you don't need a case (although a piece of screen protector would definitely be a good idea).



I have a screen protector, and am aware its waterproof, just don't want the unit to get too scratched and scuffed when I take it off the bike and its kicking around in my bag...



andym said:


> PS you should have put this in a new thread.



I meant to, am not sure how this happened - can I change this?


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## psmiffy (8 Oct 2009)

i have a vista and yes the case is no good for day to day use -the mount is a bit rattly but was all right when it was new - ive given mine a substantial amount of abuse including thowing it across several road and its still in fair nick - the screen is very durable - mine has hardly any damage - its actually the rubber parts that seem to suffer - after a good soaking the glue sem to go a bit - waterproof wise mine has been sat on the handlebars every day for 10hours since the begining of june and has seen some pretty horrible weather without any problems


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## andym (8 Oct 2009)

psmiffy said:


> the screen is very durable - mine has hardly any damage -



You're obviously way too sensible to put it in your pocket with a set of keys.



oxford_guy said:


> I ... just don't want the unit to get too scratched and scuffed when I take it off the bike and its kicking around in my bag...



Put it in the case when you take it off the bike?


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## oxford_guy (8 Oct 2009)

andym said:


> Put it in the case when you take it off the bike?



It will only fit in the case if you unscrew the bike adaptor that screws into the back of the unit (this then clips onto the rail mount, you see..), which is way too much hassle to do each time I take it off...


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## psmiffy (8 Oct 2009)

Andym - it not a matter of being sensible - I grew out of that ages ago - just never take keys on tour with me - as i posted apart from the rubber protection they are very durable - when mine is not on the bike it lives in the bottom of a nylon shopping bag with all the other junk i take off the bike in the evening 

as an aside when i was writing the first post i suddenly coulnt find it -rushed to the toilet block to see if it had gone in the washing machine - that would have been a test of its durability - thankfully it had got put in the bag with my journal


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## andym (8 Oct 2009)

oxford_guy said:


> It will only fit in the case if you unscrew the bike adaptor that screws into the back of the unit (this then clips onto the rail mount, you see..), which is way too much hassle to do each time I take it off...



Get a different case? eg something like one of these or one of these.

psmiffy: My advice to put on a screen protector came from bitter experience. Keys vs Garmin screen - the keys won.


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