Comment by quickthrowman

Comment by quickthrowman 3 days ago

Changing the voltage doesn’t change the amount of power being used, the only thing that would change is the ampacity (which only impacts conductor size, in this case).

480 watts == 10 amps @ 48V == 15 amps @ 32V

An electrically commutated motor (brushless DC) in an e-bike will almost certainly have a speed controllee, if you want more range you simply have to go slower ;)

shkkmo 3 days ago

Reconfiguring a battery pack with the same number of cells doesn't change the power contained in the pack. However lowering the voltage will lower your top speed (if not already artificially limited by the controller) and raising the ampacity of the pack may allow you to get more torque from the motor if you haven't saturated the motor and you change the controller settings to pull more amps from the battery.

Reply View 1 reply

quickthrowman 2 days ago

Ah yes, DC motor speed is controlled by voltage. Glad to see Cunningham’s Law still holds true, thanks :)
I’m much more familiar with three-phase AC induction motors from my day job and the speed on those are (most commonly) controlled by adjusting the frequency with a variable frequency drive while maintaining the same voltage instead of directly controlling the voltage like on a DC motor.

Reply View | 0 replies

swader999 3 days ago

Yeah but the wind kills range much more so at the higher speed 48v gives you and you tend to never run at half throttle.

Reply View 0 replies