This looks like the place to ask this question.
Does anybody know how to combine the two. Batteries and a hub or tire rubber generator?
It would be really slick to be able to charge a high powered battery while riding on say a 3 day weekend tour. Or a gps, cellphone, get the idea.
B&M makes a 12 volt gen (tire rubber type) 6 watt output.
By the way I love my SON too.
I agree those 10+ watt light systems do put out more light, but how I usally ride the gens output is sufficient.

Serious about the question and electrical engineers out there?