HELP-Motor Cutting Out (Video)

During the middle of my ride today, my motor started cutting out. I just built the board and was testing it and this happened, so I lowered the Batt Max and messed around with a couple other settings and it was fine until like 20 min into the ride when this starts happening:


I am using a Maytech Dual VESC. These are the current settings that I have:

  • Motor Type : BLDC Unsensored, Split PPM
  • Motor Max : 80 A
  • Motor Min : -35 A
  • Batt max : 15 A
  • Batt min : -12 A

Settings from Skatemetric Foosted guide/

Battery: 10s3p Samsung 25R which can do 60A (bypassed BMS for discharge). Motors: Dual 6354 200kV

It only happens a few minutes into riding. I initially thought that the VESC could be overheating so I reduced the current limits for the battery.

Help pls, I wanna ride and not die lol


@esk8snith That looks like a wire connection issue to me. I’d open it up, unplug and replug all the connections check any and all of your solder joints, redo the motor/sensor detection, recheck all your other settings (PPM values, voltage cutoff, everything) and try again.

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i just taped all my motor bullet connectors to make sure that they weren’t touching each other. I was also noticing cutoffs when my voltage dropped below 31v while accelerating.

i’m gonna try it out not and see but do you know what else it could be since it doesn’t happen at the beginning of rides and only happens at low battery.

If my VESC voltage cutoff is 31v and my battery sags while accelerating is my vesc just gonna cut out?

Its looks like a poor connection for me too, do you use a loop key? Maybe when you are using the board, the connector get slightly loose…So una vesc get more current than the other. Also if you experience too much voltage sag, it could be the batteries quality (maybe fake cells?)…An my last point of view, 80amp motor max with a 10s3p, isn’t that too much?

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All connections are solid now for sure, only one of the motor cuts out too for some reason.

And i use an Antispark that’s built into the VESC

No it won’t cut out completely, but it will reduce power output to protect your batteries. Are your batteries fully (or at least mostly) charged during your testing? and how far apart are your cutoff start and cutoff end voltages from eachother?

i’m at 31 and 28 for cutoffs. currently it’s not it’s at 20% but it’s also been happening at around 40-45% battery

it’s not just cutting out my motor is locking up for a second and then the belt is slipping

Are there any differences in settings between your two vescs/halves? Have you tried checking faults in the vesc tool console?

You have a pack constant discharge of 60A…Pushing 2 motors at 80A it is too much for the battery set up. Therefore after a few minutes of drive (if you drive hard it gets worse), your batteries are draining with too much stress, so the closer you reach the safety cut off, the ESC will activate the cut off. If you are willing to test 30A motor max and 30A battery max, linear, many it is just that. In that case the solution will be increasing cells in series and parallel. Imagine you are creating a voltage sag at 32V goes down 4V when you push the throttle, that would be 28V, a good reason for a ESC to cut off…When the battery recovers a little bit, it pushing some ups again…but you are playing under the red line the hole time…

Motor amps are NOT the same as battery amps. It’s totally possible to draw 30 amps from the battery and feed 80 to the motor.

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You may also check your cut of time and amps, I use 10amps so it won’t create a sudden stop if a fault happens…

I am having a similar problem, my configuration is two Flipsky 6354 190KV / VESC 4.20 dual plus / 10s4p engines with BMS 100A for loading and unloading.

My current configuration is recommended by Flipsky:

Current Max Motor: 30A
Current Max Brake Motor: -25A
Absolute Maximum Current: 130A
Slow ABS Current Limit: True
Battery Current Max: 30A
Battery Current Max Regen: -25A

But I still get cuts on my board. I don’t understand how to calculate these values?

I think there is a limit to push volts from a battery…motor and bat amps…also motor get stator saturation at a certain point…so I disagree with you

Unless there is something wrong with the ESC, I would check all of the connections, at all leves…I had a similar issue not long ago, my anti spark was getting just a little bit loose…one of my motors pushed ok, the other one not much…fix it , everything runs great now…

Yes, you are correct that there is a limit on the voltage from the battery. But the motor has a lower impedence at low speed due to lack of back-EMF - more current can flow. The vesc acts like a stepdown converter, converting high voltage at low current, to lower voltage at higher current.

Test it yourself: get a meter that can measure AC and DC current. Put it on your battery wire and then on one of your motor phase wires. Under load at low speed, the phase current can and usually will be higher than the battery current.

I’m going to check the connections, but beyond that do you know how those values are calculated? For example why put) Current Max Motor: 30A / Current Max Brake Motor: -25A Battery Current Max: 30A / Battery Current Max Regen: -25A), and not set other different values?

I’ve done that many times…Agree with you too…But 10s3p…thats only 60amps continues…If he is pushing to hard, voltage sag will be created by battery stress…A complete cut of and coming back from the dead could be read at the ESC like a regenerative energy = stopping…So I just think it is a mix of the way you ride, your set ups, climate, etc… If things get warm…everything is possible…Also they should check if they have the latest firmware downloaded…