Bicycle with USB ports to charge devices off a built-in dynamo


20 Responses to “Bicycle with USB ports to charge devices off a built-in dynamo”

  1. Chauncey Scott says:

    Pretty cool. Hope it’s waterproof in some capacity. 

  2. puufuu says:

    I’ve been doing that for years. Hub dynamos are pretty common in (some parts of) Europe and have been for quite a while. I built my own circuitry and wired the plugs on my own though; fried quite a few batteries in the process ;-).

    Nowadays there are a number of (battery-buffered) commercial products that you just plug into your hub dynamo. Much easier.

  3. dr.hypercube says:

    Peter White Cycles is an excellent resource/supplier for anyone interested in bike dynamo lighting or power. Full disclosure – he built a wheelset this summer for my night and snow bike that I am completely satisfied with.

  4. jaypee says:

    More specifically, it uses products from Supernova.  They’re made in Germany and super bomber.

    Waterproof and super well engineered.

  5. That’s such a good idea!

  6. Bottle Imp says:

    How much added resistance are we talking about here? I’m already enough of a candy-ass on hills.

    • puufuu says:

      Most hub dynamos are designed for 3W/6V (many are limited to this) or 6W/12V (not quite as common) output. A good(!) dynamo is about 60% efficient at normal cycling speeds, which means roughly 5-10W power consumption. Depends on the device you attach to it though; a hub dynamo will only produce as much power as your device draws.

      A typical rider will  produce upwards of 150W of power; pretty much insignificant in other words ;-).

    • dr.hypercube says:

      There are some graphs here (via Jan Heine and the excellent Bicycle Quarterly). I don’t notice much additional resistance w/ no load on the Shimano DH-3N80 I have, but it ain’t no race bike. Unsurprisingly, I’m no Eddy M. either – I don’t mind chugging up a hill like the robust, as opposed to gracile, older guy that I am ;-). 

    • shannigans says:

      Totally depends!  The two hub generators I have I barely notice at all and just leave them on all the time.  I have a newer bottle generator that is noticeable but not unbearable and an older bottle generator from the 70′s that sure helps to provide a good workout.

  7. great product, i could actually use something like this.

  8. Albert Hardy says:

    A very practical answer to the resistance issue is to disengage the dynamo when pedaling uphill and engage when coasting downhill.  This principle is used in hybrid autos when braking.

  9. Faith Landsman says:




  10. hymenopterid says:

    I just got a great idea for a cheap wind generator…

    • Anony Mouse says:

      Old Sturmey Archer dyno-hubs are in demand for these kind of projects. Particularly the dyno-3 and dyno-4 models, which integrate the dynamo and internal gears in a single unit, as this enables the fettler to adjust the gearing for windspeed. 

  11. The power collected could be used to run a motor that helps on the hills!

  12. JMB98115 says:

    I’d rather have a dragless¹ magnetic induction generator.

    ¹ drag from magnetic fields negligible in this application.

    • Anony Mouse says:

      Pretty sure that this is how a hub dynamo operates. Drag from a good one is very low – the equivalent of a 3 foot incline over a mile or so.

      This idea is not a new one – there are plenty of retrofit chargers for dynamo systems. It’s nice to see it well-integrated in the build – not wires dangling everywhere.

  13. You_Sir_Cannot says:

    Today I also learned that there are other types of dynamos apart from the “bottle” dynamo. Thanks BoingBoing.

  14. PrettyBoyTim says:

    I was thinking only today I need to work out how to power fairy lights from my dynohub in the runup to Christmas…

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