Let's face it, many of us never get beyond the fuss of achieving our desired speed using a given voltage and motor wind.
Which is fine of course, as long as we accept the reality of being limited to a certain choice of winds and voltages.
But it's always raised a question to me, am I more efficient going with a low resistance motor at lower voltage or the other way round?
Sadly, my knowledge is limited to ohms law, Justin's hub motor explanation at ebike.ca, and endless tinkering with his simulator. As for the theory, I've gathered that any motor wind is equally efficient at given speed and power, as long as copper losses are the same. Yet, anytime I play with the simulator, the outcome is that faster winds are less efficient.
I've tried to narrow it down to the motors only, using the simulator with extremely low battery and controller resistance, but even so the 5304 still has slightly higher torque than the 5302 at half voltage and double battery current. As much as 5-10% difference at low speed under acceletation, but gets smaller gradually the faster we go, reaching only 1-2% at high speeds.
Which leads me to believe that all the difference comes from voltage lost in phase wiring under higher current, and perhaps being unable to fit the same amount of copper using thicker copper wire.
Which is fine of course, as long as we accept the reality of being limited to a certain choice of winds and voltages.
But it's always raised a question to me, am I more efficient going with a low resistance motor at lower voltage or the other way round?
Sadly, my knowledge is limited to ohms law, Justin's hub motor explanation at ebike.ca, and endless tinkering with his simulator. As for the theory, I've gathered that any motor wind is equally efficient at given speed and power, as long as copper losses are the same. Yet, anytime I play with the simulator, the outcome is that faster winds are less efficient.
I've tried to narrow it down to the motors only, using the simulator with extremely low battery and controller resistance, but even so the 5304 still has slightly higher torque than the 5302 at half voltage and double battery current. As much as 5-10% difference at low speed under acceletation, but gets smaller gradually the faster we go, reaching only 1-2% at high speeds.
Which leads me to believe that all the difference comes from voltage lost in phase wiring under higher current, and perhaps being unable to fit the same amount of copper using thicker copper wire.