I have four technic Large motor, all connected to a technic hub. I am using the motor to turn some large propellers and the hub is powered by six 1.5 V (maybe less) batteries. So each motor would get 9V, but the current would be 1/4 of a certain value. I want to increase the power supplied to each motor while use the same technic hub. I remember that according to the manual, the hub can handle 12V at most. Is this true? Can we increase the input voltage by connecting a more powerful battery to the hub?