under heavy loading say up a slight hill or near stall it can draw a lot more current.
one school of thought suggests the 'push on/release off' control actually has an advantage, while 'off' and coasting the motor and drive train is cooling and also saving some juice, on a variable control system your likely to be constantly applying power over longer periods.
great thing about C5's is they lend themselves to experimentation, so i'm not trying in any way to dissuade your enthusiasm. earlier this year i bought the yellow C5 in the main picture. it is fitted with an early 24 volt variable control, i'm told by Karls it;s simular to one he has.
i've only just got it going, mainly due to time constraints, no major faults just some basic attention to detail and wiring skills needed, early days as to prove theories either way
.
Alan