dynamo hubs

iclestu

Anyone got one of these?

Im currently working notice of redundancy at work and, provided they dont find me an alternative role at the last gasp, am planning on doing a leisurely LEJOG in aug.

I'd be camping most of the time so it seems like a good plan to be able to charge my phone etc as i go.

Also musing the possibility of a GPS device. Would such a device run pretty much indefinately from a hub dynamo? Anyone got any experience?

UndercoverElephant

Yup, I do. I run my front light off a Shimano 3N80 hub dynamo, works a treat. I've never used it for anything other than lighting, though. I do know that Busch and Müller have something called the eWerk which does exactly what you're after, but it's certainly not cheap.

http://www.bike-discount.de/shop/a20945 ... html?lg=en

DrLex

Can you wield a soldering iron (or know someone who can)? There are plans on t'internet for making a cheap USB charger from basic parts available at Maplin/RS/Farnells.

davis

What kind of GPS device or electricity loads would you be looking at? There's a possibility you can charge some small gear from portable battery packs, and charge those from solar power (slim possibility). I suspect your dynamo idea is doable too -- the Shimano 3N80 that UE mentioned puts out 3w at 6V, which is in the ballpark: as a guide, I'd say an average phone charger is around 1.5W - 4W. I think any random GPS device is likely to be higher draw.

Another option might be one of these, charged up when you can.
What devices are you looking to power?

sketchley

You've got to sleep somewhere, most camp sites even the cheaps ones have a bar or common area where you can plug in of an evening even if there's a small cost it's still cheaper than a dynamo....

Edit: Also 2nd battery for phone and external charger, it'll still be cheaper.....

iclestu

davis wrote:

What kind of GPS device or electricity loads would you be looking at? There's a possibility you can charge some small gear from portable battery packs, and charge those from solar power (slim possibility). I suspect your dynamo idea is doable too -- the Shimano 3N80 that UE mentioned puts out 3w at 6V, which is in the ballpark: as a guide, I'd say an average phone charger is around 1.5W - 4W. I think any random GPS device is likely to be higher draw.

Another option might be one of these, charged up when you can.
What devices are you looking to power?

phone & gps device. Prob a shiny new garmin edge?

Am interested in how effective this device would be. One can buy a shedload of aa batteries for the price of a dynamo hub!!!!

iclestu

Sketchley wrote:

You've got to sleep somewhere, most camp sites even the cheaps ones have a bar or common area where you can plug in of an evening even if there's a small cost it's still cheaper than a dynamo....

Edit: Also 2nd battery for phone and external charger, it'll still be cheaper.....

i hear you.

I am travelling alone tho with the smallest tent in th
e world. I mightnt always be at a campsite.

You are probably right tho, just mulling over the possibilities i guess

davis

iclestu wrote:

phone & gps device. Prob a shiny new garmin edge?

Which phone etc? There's a world of difference between the latest fancy-pants Android slab and a rinky-dink Nokia.

As a total stab in the dark, that battery pack at (9V * 4 Amp hours) is 36 Wh, which might work out at running a small USB charger for around 10 hours. That small USB charger would probably charge a smart phone, which means you might get (say) 3 full charges of an average phone out of 1 fresh set of batteries. I don't know what the Garmin would require to charge, 'cos Garmin are coy about their specs.

[edit]: Hmm, ok the Garmin Edge 500 looks to be a USB-charged device. Assuming it stays roughly within spec then I 'spose it'll take a bit more power than a phone. I'd estimate that one of those AA sets would charge an average phone and an Edge once each.

This is all guess work, really. It's finger-in-the-air estimation... just look at the number of times I've used "might", "possibly", etc!