I have a RadCity that as far as I can tell, has regenerative braking, charges the battery while costing and going down hills without pedaling. The problem is that there is no way to charge the battery while pedaling. I think that all I need to do is add a switch to the cadence sensor. With cadence sensor off, I could pedal on level ground (more exercise) and pedal down hills, charging the battery while doing so. The problem I have now is that on long trips, without a lot of down hill, the battery dies after 20 to 30 miles of pedaling and then as long as I keep pedaling, the battery never charges. On long trips, I'd love to keep the cadence sensor on anytime the battery is full and off the rest of the time except when climbing hills (even with gradual slops) or accelerating after a stop light (for example). Has anyone done this? I was thinking about using a really nice head light switch but would that have too much resistance for the weak signal generated by the magnets passing the sensor? Before I strip the sensor cable, are there just two wires in there? Is it a passive sensor? Or does power go to the sensor?