Need help to choose my new controller

[enabor]

Hi everybody,

I'm a newb here. I bought a second hand lonestar scooter (https://www.youtube.com/watch?v=f5bwIDJMmEs). I'm really happy with it but I would like to increase a little my speed (yes I know legally I should stay at 32 km/h) to reach 50 km/h. My batteries are 72V SLA (for now, I'm planning to use lithium next year). I guess the motor is a 500w. I made some research but I'm still not sure which controller I should go with. Should I buy a bundle like this one from QS motor (http://www.hs-escooter.com/sdp/1012...60V_72V_10inch_Hub_Motor_with_Disc_brake.html)? or my current hub motor would be enough to reach 50 kmh ? Should I buy a generic controller or the Kelly controller are way better ? The adaptto controller is nice but very expensive... Any suggestion would be very appreciated since I pretty lost here Thanks !

 

[aaronski]

For any motor more VoLTs 2"will give a higher top speed assuming unlimited amps.
More amps will give faster acceleration, same top speed for the same voltage.

I don't know that scooter, but the first thing i did is ditch sla for lithium. Lighter is faster
Also less voltage sag is faster.
When you push lead acid batteries the voltage drops a lot. Your 72v battery may output 60v when you accelerate. Since top speed=volts, you are losing top speed due to that voltage sag.
My hobby king multi rotor pack goes from 72v to 70v under a 60 amp load. Which is not much, so I keep my top speed and acceleration high.
Go lithium.

 

[enabor]

I am aware about the voltage dropping during acceleration and my plan is to use lithium at one point, but still, I measured the voltage/amp when reaching my top speed on a flat road and the voltage is still above 72V and the amp is pretty low (around 5 amp per hour) while it need a lot more amps during acceleration. My guess is either the motor is reaching its top speed, which I doubt, or the controller is limiting the power when reaching a specific speed. Am I wrong ?