Understanding max speed of wheel

defuzo said:

And if you supply higher voltage?

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karstensson said:

defuzo said:

And if you supply higher voltage?

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Sadly, I do not have the possibility to test that.

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karstensson said:

Hello,

I am struggling on understanding how the max speed for my hub-motor works when it's controlled by a controller with the following open source software: https://github.com/EBiCS/EBiCS_Firmware
In the firmware the current is set to 15A and max speed to 255 km/h.

Still the wheel only spins up to roughly 25 km/h, even when its spinning freely (at this time the current is 0.5A).

Any suggestions on where this limitation could be? Is it really that the motor has reached it max rpm?

It is a bafang 250 w motor

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E-HP said:

So higher voltage, higher speed; lower voltage, lower speed. There is no limitation besides the voltage being applied. You can learn more by searching on motor kV.
https://www.youtube.com/watch?v=zHpFGPvmibM

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BalorNG said:

E-HP said:

So higher voltage, higher speed; lower voltage, lower speed. There is no limitation besides the voltage being applied. You can learn more by searching on motor kV.
https://www.youtube.com/watch?v=zHpFGPvmibM

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I'd note that applies to *UNLOADED* motor only
Power to overcome air drag actually increases by CUBE of speed at high speed.
Therefore, to double the speed, need to increase voltage two times and current 4 times, roughly speaking.
If you install a fairing that will half aero drag, you can get away with 'merely' doubling voltage and current.

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E-HP said:

BalorNG said:

E-HP said:

So higher voltage, higher speed; lower voltage, lower speed. There is no limitation besides the voltage being applied. You can learn more by searching on motor kV.
https://www.youtube.com/watch?v=zHpFGPvmibM

Click to expand...

I'd note that applies to *UNLOADED* motor only
Power to overcome air drag actually increases by CUBE of speed at high speed.
Therefore, to double the speed, need to increase voltage two times and current 4 times, roughly speaking.
If you install a fairing that will half aero drag, you can get away with 'merely' doubling voltage and current.

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Yup, but since he asked about speed of the wheel and provided no other details, I went with answering that question rather than go through a bunch of q&a.

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