Forgive me for saying so, but that is a strange question! A motor controller works by switching the full battery voltage on and off very rapidly and it controls the motor by varying the on to off ratio, so your motor always "sees" the full battery voltage while the controller is on. Basically, that on
ff ratio is controlled by the throttle, ie full throttle = always on, no throttle = always off. So you see why that is a strange question.
If you look at the controller pages you will find reference to the controller parameters that may be varied by the user.