Voltage supplied to Roboclaw vs Voltage supplied to motor

[Basicmicro Support]

No, you cant. Motor controllers dont work that way(at least the vast majority dont). Most Motor controllers use PWM to drive motors. This means they turn on and off the supplied voltage at some duty cycle and frequency to control power to the motor. The motor brushes will see the full battery oltage. Since the brushes are usualy the reason for a particular voltage rating on a motor you have to take into account the voltage they will see(eg 24v in this case. In general you can over drive a motor by 50% with little extra wear. Driving 100% over the rating though will probably wear the motors brushes down signigicantly faster. This could still take a while before the brushes wear out but the manufacturer rated the motor at 12v for a reason.

In general I would recommend going with an appropriately sized battery.