Honda Powered Electric Bike??

Discussion in 'Electric Bicycles' started by andyinchville1, Aug 6, 2007.

  1. HI,

    Has anybody ever bought one of those small and extremely quiet honda generators and powered an electric bike with one?....Some of the generators are so small you could almost build a small rack for it out back and run maybe 2 hub motors....That would be neat!


  2. Lowell

    Lowell Guest

    Problem is that those generators are only 1kW, so you could barely run one hub motor off it. I like the idea of an electric hub motor, with a gas drive motor directly driving as well. A regen controller can be used to charge the batteries if desired.
  3. weez

    weez Member

    If one put some smallish batteries in the system to deal with transient power demands, I could see a 1000W genset driving a pair of 600-700W hubmotors. Only on hard acceleration and hillclimbing do you use all the output of the motor- most of the time, on more level ground, only a fraction of the motor's output is used. Batteries of about 14AH in parallel with the motor speed control output could cope with sourcing the 400-500W the gennie can't supply, in the short term. When the load reduces, the genset returns to charging the batts.

    One would have to be a bit clever in connecting the speed controller and batts to the motors. The batt charger used would also have to be fairly grunty as it would see the load of the motor on high demand, though would be sharing it with the batts and the spd ctrl.

    It'd be a bit more practical if the genset were wound suiting the motor voltage i.e. 36-48v so it could be connected straight to the batts without a charger (perhaps some current limiter ckt would be needed), but the little Hondas usually are wound so their main output is 120/240v but some also have a second, low-current, 12V batt charging winding.

    Mains AC batt chargers usually only deliver a few amps, not the 30-40 an ebike may need on hard acceleration. If one plugged a mains voltage charger into a genset, not much of the gennie's output capacity would be used.
  4. Drunkskunk

    Drunkskunk Member

    I bet it could be done, But...

    a 500watt motor will pull 1500 watts while accelerating, so a 1k generator wouldn't keep up.
    Plus there is an efficancy issue. a 1k generator's motor is probably putting out 1200 watts at the shaft, but by the time you convert it to electrical power and run it through the battery charger, the battery, the controller, and the drive motor, the output on the shaft of the motor might not be more than 600 watts. It might be more efficent in that case to just hook the gas motor up to the wheel and skip the electrics.
  5. loquin

    loquin Active Member

    We had a similar thread on this topic a few weeks ago here.
    Last edited: Mar 3, 2008