parajared wrote:I think I know what Wes is talking about. You can dump 100,000 watts down a tiny wire and not overheat it if you keep the amps low (say 100,000v 1amp) but if you have low volts, high amps, all sorts of stuff gets hot (speed controller, phase wires, motor coils ect..).
Upping voltage would also yield the benefit of higher top speed, but watts are watts, the motor will handle wattage the same and can still run into trouble if you put too many watts into it.
In other words, if I want to go up hills at 2500watts the motor will act exactly the same, but I could run 28 amps instead of 52; all I need do is wire my batteries in series instead of parallel so that I am running at 90v instead of 48.
Well... that and buy a whole new speed controller
This holds true for the wires from the battery to the controller. But it does not work that way for the controller to motor wires. The conditions there are determined by the power being delivered to the motor and the motor speed (back EMF) and a few other things like wire resistance. The controller converts the higher battery voltage to the lower motor voltage - it is essentially a buck voltage converter. So raising the battery voltage doesn't reduce motor phase current. Raising the battery voltage won't cool the phase wires. It will increase the power that can be delivered to the motor, and the top speed, and so will likely make the phase wires hotter because it will be possible to put more power in, and it will make the controller run hotter and less efficiently and put more stress on the FETs.
One other thing that raising the voltage will do. It will increase your ebike smile.