Self charging an electric bike? Answered
Hi all, I am always amazed at the ingenuity here and after many years of being fascinated I would like to ask my first question. I'm thinking of getting or converting/building an electric cycle. I've been told by local dealers that none except the very expensive have a recharge facility for sat when you go downhill or are freewheeling, That seems a waste to me so I am thinking ... why not buy a used wheel with a hub motor and fit it at the front wheel and that raises the following questions in my mind ...
Can hub motors be used in reverse as generators?
Would the output be speed (rpm) dependent and if so then if said cycle has say a 36 volt system would it only charge the battery if the 'generator' is producing 36v or close to?
If so would it be better to find perhaps a 24v hub motor to use as a generator and charge the battery via a variable input, 36v output step-up?
I appreciate it will be less than 100% efficient when both using electric at the motor and charging at the 'generator' but would anyone have any idea how inefficient? I'm fit enough to cycle on the flat but would appreciate help on the hills!!
I assume I will need a diode or similar ... does anyone know where I can find a suitable circuit diagram
Lots of questions I know ... sorry.