if the controller only gets 12 and as such tries to chop into 12V 'blocks' (PWM)
if the motor is designed for 24V and rated at 240W , the power Amps the controller has to chop will indeed be 20 .
I sometimes compare PWM with pushing a stalled car(compare with eletrics between brackets )
...alone or with two
when alone it will go slow (V) ,you need to put up a lot of force (A)
(and you will be exhausted very quickly )
with two it will go fast (V*2) , you need to put up less force (A/2)
there will be no difference between direct drive or controller , in the circuit the only constant is the motor's watts by design (e.g. 240W and 24V)
so yes in both case it will run half the speed but will draw double the amps.
direct drive is even worse in this case as the motor requests the full torque instantly = (full 20Amps..or more) , where the controllers has electronic limitations to prevent high current draw.
my other jeep also runs on 12V for safety reasons, the motor is 400W , from still to full (pedal to the metal figurly) the current goes over 50amps !!! (controller limit)
Due to the Geepstar i'm assembling i did some more investigation and decide to rewire to 24 , limit the speed electroniccaly . in 'playtime' it will be more or less the same, the lifetime (e.g. motor, battteries ) will incease drastically(i hope)
something i always forget is that some motor are not designed to draw double the rated current .
regs,
Luc
