Q100 loses power, makes whining noise at low speed

[vfr400]

There is no torque simulation in these controllers. It's just a name. There is no setting to make the throttle the same as the pedal sensor. It's always speed control and always gives 100% power when fully open. If you want less power, don't turn it as far. Some versions of that controller don't give proportional control, where the throttle works as a switch, making the controller go straight to level 5 so more like an instant level 5 switch. They're always changing the software. You never know what you're going to get until you scan through all the parameters in the settings.

A 12FET controller is too much for a Q100. The gears won't last very long. I tried one myself and after a few hundred miles, the gears were about half the thickness of when they were new.

 

[AviatorTrainman]

Hi, just to clarify, the throttle setting is roughly proportional to top speed. If it put it at halfway, the controller will put full power until ~25 km/h. More throttle, higher speed, and vice versa. WRT current, I have the C5 value set to 03 most of the time, for 15 amps, and 04 when I really want to go for 20 amps. This should preserve the motor, yes? After running hard at 20 amps, the case of the motor measures between 30 and 32 degrees Celsius. How does this translate to the internals? Am I cooking the motor by doing this, or is that just fine?

 

[harrys]

20A is 20A, whether you get it thru 6 FET's or 12 FET's. If that C5 setting works as advertised, the Q100H should be OK.

I agree it's not torque simulation, but it is a smoother delivery of power than some other controllers. I've gotten used to the KT feeling and the cadence sensors on other controllers I own is feels crude enough that I had to scrap them.

 

[AviatorTrainman]

20A is 20A, whether you get it thru 6 FET's or 12 FET's. If that C5 setting works as advertised, the Q100H should be OK.

This is a Q100C. My understanding is that the C takes less power than the H. Is 20 amps okay for short periods on the C, or do I need to keep it at 15? I try not to keep it at 20 for more than 30 seconds continuously, just sometimes while powering from a stop or at the base of a hill.

 

[Nealh]

Though not torque control as in a drive, the PAS using the 5 assist levels do give differing amp delivery levels and this is what is referred to as torque control.

 

[vfr400]

You can confirm the current setting by watching the power shown on the LCD. Which speed version do you have? The slower one can work with a higher current controller because it doesn't allow high current at cruising speed.

 

[wheeliepete]

The slower one can work with a higher current controller because it doesn't allow high current at cruising speed

How does that work then? is it because it's near max rpm and not drawing as much current?

 

[AviatorTrainman]

This is the 201 RPM version running at 48 V. The controller shows 650 and 850 W at C5 values of 03 and 04 respectively.

 

[AviatorTrainman]

How does that work then? is it because it's near max rpm and not drawing as much current?

From my understanding, that's exactly it. To quote user DuncanDK, "the motor builds up a backdraft voltage as it spins up." Thus, at higher RPMs, the controller is unable to push in more power because the motor is "pushing back" with nearly as high a voltage as the battery.

 

[wheeliepete]

I can see how that works near the max. speed of the motor, but not how it makes a slower motor capable of handling more current. After all, your not cruising 100% of the time and we don't all ride at the same speed. If you ride fast, then surely the same could be said of a fast motor.