Author Topic: New Siva dyno-charger/battery may be coming  (Read 4096 times)


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New Siva dyno-charger/battery may be coming
« on: April 24, 2013, 05:07:47 PM »
Hi All!

Siva Cycle embarked on a Kickstarter campaign yesterday to raise funds for a production version of their Atom USB dyno-charger (with integrated AC to DC current rectification) prototype and are about 1/3 of the way to their goal at present.

You can read a summary article on Gizmodo:
More details on the Siva Cycle Atom Kickstarter page:

Unlike other dynochargers, this self-contained unit attaches to the left side of the rear wheel and includes a detachable 1300mAh storage battery. The unit itself uses a 3:1 geared drivetrain to produce standard USB voltage/current of ~5.0vdc @ 0.5A (500 mA). The prototype weighs 10.5oz/~300g.

Siva claim 80% efficiency, but that remains to be seen in actual testing. I'm a bit skeptical, and would imagine the drivetrain would add both drag and noise. There appears to be no off switch, so it would be generating all the time and the unit is captive to the rear wheel, which can be locked to prevent theft. The unit snuggles along the rear side of the seatstay and promises to clear racks and mudguard stays. The makers promise future compatibility with disc brakes and perhaps an option to mount it on the fork. The unit appears incapable of powering a dyno light directly, but could charge a battery light or power a plug-in light with the DC battery current. They promise greater power and efficiency in production versions.

I would very much prefer a modern SON, Shimano, or SP dynohub with attached charger, but it is encouraging to see further development of on-bike charging and I hope one day such things will be truly commonplace (with prices falling as a result). I do like the idea of a dyno powered by the rear wheel, as it offer the opportunity for a quick battery top-off by inverting the bike and turning the cranks by hand. My dream is a "someday" Rohloff/Schmidt collaboration for an integrated hub gearing/charging solution, perhaps located on the hub's left-side disc mounts.