electric trike build , and wiring , volts x amps =volts questions

Discussion in 'Electric Bicycles' started by thescooterguy, Dec 26, 2008.

  1. thescooterguy

    thescooterguy Member

    electric trike build , and wiring , volts x amps =watts questions

    I'm building and electric trike while i was stuck in the house due to snow storm . . i have a motor rated at 36 volts 12.5 amps 350 watts , pretty much have it all together . I'm down to hooking up the batteries , controller , and throttle . i haven't bought them yet because i'm not sure exactly what I'm doing , the basic controller I'm looking at for 36volts has 7 connectors , and its 40amps , the 36volt throttle has 4 wires , that leaves 3 more connections on the controller . one for battery in and one for out to motor , do i need to hook the last wire up from the controller to something for it to work . not sure what the last wire is for , i plan on running three 12 volt 12 amp batteries in series that's 36 volts but the amps confuse me the motor is rated at 12.5 amps the controller is rated at 40 amps , the fact that these # don't match worries me . and 350 watts doesn't make sense i thought that volts x amp = watts , the motor says 36 v 12.5 amps 350watts but 36 x 12.5 = 450 watts the motor says 350 . my batteries 36 volts x 12.0amps =432watts . will this harm anything . pictures of befor and after trike build older free spirit montgomery ward . i think

    Last edited: Dec 27, 2008

  2. skyl4rk

    skyl4rk Guest

    Is the motor brushed or brushless?

    If brushed, this controller would work:

    36V 25A Sparrow Speed Controller on this page:


    If the motor is brushless, this controller MAY work:

    36V 25A RoadRunner Speed Controller

    The brushless motors have five wires to the motor (or hubmotor), three of which are known as Hall Effect sensors.

    The brushed motor controllers generally have two wires that go to the motor.

    Note that the controllers also have wires to connect the batteries and the throttle.
  3. thescooterguy

    thescooterguy Member

    it must be brushed , it has just two wires ,
  4. thescooterguy

    thescooterguy Member

    Last edited: Dec 28, 2008
  5. skyl4rk

    skyl4rk Guest

    Its hard to say, they don't list any specs. There are other reasons for wires being there, like a brake actuated motor shut off, or gauges. It does not look like a brushed controller to me.
  6. thescooterguy

    thescooterguy Member

  7. skyl4rk

    skyl4rk Guest

    Looks to me like you are on the right track. I couldn't reference the model number back to the original links you posted, so I don't know which model the schematic refers to. You might want to find another supplier because it will be a pain if you get stuck on something and don't have any tech help to fall back on.
  8. thescooterguy

    thescooterguy Member

    got my controller today with throttle , seamed to go together got lights on the throttle but no power to motor , switched a wire and got smoke and sparks , no more light , no nothing , blew the controller , I'm sure , can touch wires from motor to battery and i got motion . i think I'm going to radio shack to get a dc on off switch 36volts , maybe a dimmer should be simpler than that fancy controller . any suggestions . dont need lights or break stuff . just power to motor when i want it .