I have finished the build of the USB charger using the kit I had bought off EBay. As planned everything worked out quite well and it readily charges my booster battery pack. However the Droid will not charge but this is probably due to not incorporating the data circuitry needed.
The super capacitor circuitry worked fine and would keep charging the battery pack for about 5 minutes after the wheel stopped rotating. But found the charger had a large enough capacitor without the added circuitry to smooth out the fluctuations. If I needed a stand-light the super-capacitor would be ideal.
I believe if I powered a “minty booster” with the charger I could readily and reliably charge smart phones, Android, Apple and Windows. Add the super-capacitor circuit between the charger and a “minty booster” it could really be a robust solution.
As a note I moved the Stanyan around the garage, not more than 20 feet and both the tail light and Luxos U stand-lights popped on for quite a long time. Awesome. That says something for the SON Hub Dynamo.
I am waiting for another Luxos U to arrive from Germany to go with the Shimano dynamo hub on the Bruce Gordon. The price was very good, about the same as the non-usb B model here in the States. That may because it is first generation with a plugable switch/usb cord. I have read that these units have a moisture problem. Also it seems there were problems of parts availability. The new lights come with hardwired switch/usb cords.