Question regarding voltage and current
Stepping up the voltage in order to reduce current only works if the "load" device draws a constant power and this is not the case with a DC motor. If you increase the voltage, the DC motor will spin faster. For instance, if you double the voltage, the rotational speed will approximately double and so will the torque that is delivered to the mechanical load. This means that the power taken quadruples and, the impact of all of this is that the current doubles.