What does motor MAX actually means?

I’m sorry, but that still doesn’t prove your theory. I can think of a few ways to test it, in a controlled environment. But having someone ride a board on the street has relatively 0 value. You want to prove to you’re right, you’ll need to do it in a controlled environment. Why do you think people don’t just go on the street, accelerate their cars 0 to 100, time and plug in the cars Cx value and get that HP number everyone wants to see for free? That’s right, TOO many variables.

You seem to be really good at math. Are you decent at scripting? Would you be willing to build a javascript calculator to help us get the right settings into the VESC based on these attributes you describe?

Also i street test everything i build, so the only danger is to myself as far as this particular things goes.

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Devin I posted ur theory on vedder’s site. Curious if a circuitry bit would blow with a 10000 motor amp limit or will the battery limit supersede

O ME ME ME ME ME

I can totally script the heck out of this, I am just gonna need somebody to send up a feature list, or I am going to have to read this thread from top to bottom to see what is going on. We can get this programmed up in Angular and it would be secks.

BTW, this thread, is pretty epic. Thanks for continuing to hash it out boys!

What’s the best/easiest way to determine winding resistance? A multimeter on the phase leads?

epic, thanks bruh!!!

now go back to hashing this out with @Hummie and @chinzw lolololol

hey hey! we came to an agreement! :slight_smile:

but but but… i just got some popcorn after reading you guys going back and forth so productively! lol

I have to admit that i stopped reading this really interesting topic after about 50 posts because it got way to nerdy for me :smile:

So is there a working way to get rid of the unpredictable acceleration bursts in the the area close to max rpm without damaging the components in low rpm / full throttle situations?

My Setup:

  • VESC
  • 2,2 kW 6355 190 KV (description says 80A max)
  • 5000 mAh 10S 20C (100A continuous / 150A 10-second burst)
  • Hardware car fuse 40A continuous / 60A 10-second burst

This is where it gets not nerdy and I say as a rider there’s no danger of unpredictable acceleration bursts. When u drive It often is a not perfectly smooth acceleration curve especially if ur driving a stick! U get used to it and id rather call it an acceleration profile. Getting more torque at low speeds is what this is about I believe. The possibility to increase the battery amp limit

The needle in the haystack! Some useful real world info in this thread. Thanks @longhairedboy

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With hub motors I’ve it set to 70 and would like more. I notice the difference coming from the default 60. If u can set ur battery max to whatever the max u want to pull from the battery that’s fine and makes sense but it’s possible to set the motor max to 200, just because that’s all the bldc program allows. then I’ll bet 200 rocks. Who’s going to do it. ?

Actually i am developing a new mode to control the power. And for that i needed to calculate how the actual power is calculated. So to answer your question how it would feel like with motor current set to 200 you can see it in the second picture. First picture is for 70 A motor current. Both pictures show how how much watt would be produced at 70 % throttle.

70 A Max Motor Current at 70% throttle

200 A Max Motor Current at 70% throttle

So you see that you would reach max power at 0,85 Duty Cycle with 70 A Motor current and with 200 A you would reach it already at 0,3 duty cycle. So the board would feel more powerful but you have less control with the throttle.

So to summarize it. With Max batterie Current you define the max power. And with Max Motor Current you define how much power will be created by the throttle. This counts the most at low speeds an also defines how much control you have at higher speeds.

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I made a interesting video to show the issues i see with current control.

My settings are: Motor Max 80 A Batt max 35 A

So it is 1400 Watts max in theory (35 A * 40 Volts = 1400 Watt).

For the video i added a stoper to my throttle so that the throttle will always give 50%. As you can see it nearly reaches max power even at 50% throttle position.

Live recording of Vesc

And here are the calculated numbers

So the faster you go the more you loose the ability to fine adjust the power.

I created another power control mode which lets you control the Watts by the throttle and not the current that goes to the motor. That means i can control the power in % at any speed. See this video and have a look at the Watts. It is the same rack and the same throttle setting (50 %from start on) as in the previous video. At duty cycles below 0.50 i use curent. otherwise the power would come in too hard. So don’t be confused that it doesn’t give 700 Watts from start on.

Live recording of VESC in costum Watt control mode Remark. max motor current changed from 80 to 70 to give a softer acceleration.

So you see in the graph the way i power the Motor with this new mode. You see the calculations of curent control and watt control and in the last colum on the right the watts it will use. I know it is a bit hard to understand but it feels great. Gives you much more control at higher speeds.