The generator hub of the SON appears to be a straightforward electromechanical device with magnets, coils, and no electronic regulation. It makes it very robust, but it is subject to the laws of physics, which here dictate that it generates lots of electricity at speed and very little when going slow. There is a threshold below which the SON hub will not generate enough power to charge a phone. This is about 8mph for my standard SON and surely a little lower for the SON28.
8mph? no sweat you say? I took the setup on a short tour into the N. Ga. mountains. In the rolling piedmont, everything was fine. But in the mountains with the ratcheting up and down, there was no charging while grinding out 4mph climbs and the few minutes spent in the 25mph descents couldn't make up for the lost time.
Don't know if the Pedalcell engineers did this, but there's room in the generator space for a field-regulated generator that can generate adequate power at very low speeds.
Those of us of a certain age will remember owning one of these:
https://www.youtube.com/watch?v=i7kgzgcqe5sAbout my standard SON hub. It's built into a 700c wheel. When purchasing it, I was preoccupied with it's slightly lower drag figure compared to the SON28 and missed that the '28 is designed for the lower spinning speed of 28"/700c wheels. I needn't have worried about drag. When not touring, the wheel lives on the daily commuter to power lighting. The setup is so non-draggy that I never bother to turn the lights off; you really can't tell the difference.
