Scooter Hub Motor spins the same speed with 10s, and 20s on VESC.

[trutee]

Hello all,
I recently made a new battery for my scooter, a 20s4p 84v pack. My scooter is a Ninebot G30 with hub motors on the front and back. Im using two flipsky 75100 vesc's with the fet's mounted directly to the stock controller's case. My issue is I was expecting the motor to spin twice as fast, or at least somewhat faster when I doubled the voltage, the only reason I made the 20s. However when I use the 20s battery the motors still spin at the exact same speed. With the 10s they spin around 18mph and the same at 20s. Im using FOC mode and with update firmware. When using feild weaking the 10s can spin the motors at around 21mph and the 20s can get up to 35mph. I had a previous ebike and with a chinese 12fet controller and the more voltage I gave it, the faster it ran. I thought It might be due to a ermp hard limit or somthing, but from looking at some data I am far from the limit. I also set the voltage and current limits far above what I was at, so I dont think that is an issue.
Does anyone know why this is?
Could this be related to the 75100, or maybe the stock ninebot hub motors?
Any advice is much appreciated.
Thanks.

 

[DogDipstick]

Interesting problem. I do not have any help: I just want to follow the thread for the reply.


ONE question.
.....aer you measuring ' loaded RPM" or " unloaded rpm"? the post does not discriminate the two.

 

[scianiac]

My guess is it's probably something with the controller setup, the 75100s are not known for their quality but if it's working fine otherwise I would suspect it's the setup instead. I'm assuming these are unloaded speeds? If they are loaded speeds then do you have a power limit set? Beyond that what exactly to change is a more complicated question, did you run the motor detection with the new battery, technically nothing should change but that's not always true. Maybe you detected inductance may be off? You could try and adjust the inductance up and down slightly and retest, not too much and watch for any abnormalities, messing with values too much can have bad results.

 

[amberwolf]

Note that with FOC controllers, unloaded operation is different from loaded, since they modulate phase current, not phase voltage. What difference that may make to your results I don't know, but it has made a difference to some people's setup and testing.