I am looking for an electric bike for my wife. The problem is that she has a large hill to go down on the way home from work and she does not want to spend 5-10mins constantly on the brakes. I have tried a couple of bikes like one from Stromer that has regenerative braking the problem is that it does not brake enough, when it is set to max braking (-2) the braking force is almost imperceptable.
I do not care about charging the battery (though that would be nice) what I need is decent braking force from the engine so she can cruise downhill without braking and at a reasonable speed. As I understand it the battery cannot take the whole current that can be generated by the motor but I would think there would be some way to divert that power to a capacitor or resistor (with heatsink) or something.
I would consider building my own bike if needed.

Anyone know of such a bike/conversion kit?
Seams that bionx has a system, does anyone know how well it works? Can it slow my sufficiently on a long steep hill?