Help me with VESC settings

Esk8 Electronics Guides, Support, & General Questions
#1

Hello, I’m looking for tips on my current VESC settings, also I have some questions for the more experienced people here.
My build is 12S4P 40T with bypassed BMS, 2 6374 battle-harden motors, xenith VESC. Here are my settings:

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Motor temps are set high because I had trouble on FW 5.2 when hitting Cutoff Start, one motor would start to jitter. Haven’t done any test runs on FW 5.3 to see if it’s fixed.

Having a dual VESC, that means I should split the values for each motor from what I’ve seen so far but I don’t understand if I should use Battery Current Max halved for each size. I should be able to draw 120 amps on the 12S4P (wouldn’t be continuous, 5-10 seconds bursts max) so I used Battery Current Max 60A on one motor, and 60A on the other one. From the the rides I notice that the total current in the Xenith is lower than 80A:

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Each motor pulling under 40A:
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1CAF9349-D602-416B-B4C7-B436117D418F_1_201_a1170×1642 104 KB

This is the maximum current draw I got on almost all my rides, thing I don’t understand is Current In vs Motor Current, which is almost double:
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  1. Should I increase the Motor Amps to 80A each, since my battery could put out more amps?
  2. What temp limits should I use for mosfet/vesc?
#2

I’d set it to 90 motor amps per side. Xenith + those motors will handle it easily. Keep the battery amps the same though.

I do 80C start, 87C end for both the motors and the esc

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#3

Official data is 80A cont. But I don’t trust that rating in the slightest. Cont. is more like 65A. imo.

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#4

nobody is pulling motor amps continuously ofc. 90 motor amps is no prob for a xenith

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#5

:+1:

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#6

What is considered continuous/burst intervals?

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#7

Imagine a sharp acceleration and then reaching top speed. That would be a common burst interval, ca. 5 seconds. Others would be shorter, there really is no defined standard for a burst.

3 Likes
#8

Thanks. I am also confused about the motor current. The motor specs are for the Current in or Motor inside the current (which is double than the current it gets from the battery)?

#9

Motor current and battery current are kinda independent (not really, but you can think of it this way) from each other. You ESC basically acts as a current and voltage converter to drive your motors. And such the ratings differ from each other.

If you have more questions or difficulties understanding some basics I’d recommend to ask about those in the beginners questions thread, as you get more attention there. :slight_smile:

3 Likes
#10

I linked you to a thread discussing battery vs motor current and it’s relationship vis-a-vis duty cycle in the beginners thread. Work your way through that thread and you’ll have a better understanding of how it all works. Basically, the motors and the controller bounce current off of each other and there are also capcitors in the controller which is why you can set your motor currents higher than the battery current. This is obv a gross oversimplification but that’s the gist of it. The thread goes into a (painful) amount of detail I can’t hope to explain as my brain isn’t nearly big enough :sweat_smile:

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#11

Thanks a lot!

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#12

Re ran detection. Done