It's been a looong time since my last post. I finally found a sliver of time in our busy race schedule to do the first stage upgrade to the S-650 we ride around the paddock. This is a simple 24V to 36V conversion, but the data is very real. Rider is 185 lbs. Scooter has the 650 Watt motor.
I charged up the 24V, 15 amp hr pack, and grabbed the GPS for a baseline. I also set the start and end points and distances to ensure control.
Preliminarily inflated tires to 35 psi. Rode scooter in both directions to eliminate grade and wind issues, and be able to do some averaging.
Stock, the scooter hit 17 mph in one direction and 13mph in the other direction. 15 mph average.
Went back and dropped in the 36V pack, same 15 amp hr rating. Same controller, same everything except the charger. In the first direction we saw 22 mph on the GPS, and 18 mph in the other direction, for an average of 20 mph. The GPS was also validated with a vehicle in a subsequent test for accuracy.
This is an honest to goodness 5 mph top end gain with very large gain in low and midrange torque. That's a whopping 33%. The math says that the stock motor at 24 V is 27 amps, which means that at 36V, we're looking at 975 Watts.
Stage 2 I think is to use the 24V 900 Watt Currie motor and 40 amp controller. This motor would be about 37 amps, so feeding it another 12V "should" produce around 1,330 Watts!
If anyone has already done this second step and has test results, I'd love to hear about it.