Originally Posted by Milton Keynes

All other things being equal, more volts will give you more power. Power in Watts = Volts X current in Amps. More volts, more watts. However, from my electronics experience, not all electronics work on higher voltages and you run the risk of burning them out. Plus you have to make sure the motor can handle the higher voltage as well, since with higher voltage you run the risk of burning a motor out too. With higher voltage, you have a higher current running through your circuit, and you have to make sure your circuit can handle it.