30 mph cutout to superman

I’m not sure… I think it braked after it lost power but the esc wasn’t transmitting data to metr by then… pretty sure I found the skid marks…

Charge only bms…

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Interested in the strip-down, it’s unfair to point fingers, so I I’ll keep it singular :point_up:

I have a samiliar cutout and throw off recorded by metr. are you interested to compare? It can help to see the behaviour

Thrust is quite difficult to gain especially after second throw off

Yeah share it, let’s see…

Happened at:

Are you also running dual vesc 6.6 flipsky? This is what scares me. Im trying to battle tune my finished board with programming, and then this.

In your case the voltage drops and after the current from motors and battery.
In his case first the current from motors and battery drop and than the voltage drop immediately.

You are right this is actually different

There’s a guy on the other forum whose single FSEsc 6.6 cuts out at full throttle going uphill on his bike. Might not be related, but interesting to note.


Im guessing he’s running high current limits, that because of an abs overcurrent fault; other ESCs have the same problem.

I really don’t think the ESC is at fault here. Something cut the battery off from the rest of electronics, whether it be a bad connection or (this is unlikely) the antispark turning off when it wasnt supposed to.

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@sebaszz you had a DRV error :scream_cat:


Yes I’m quite confident it was caused by cutoff of the diebieBMS on single cell voltage, because of quite a mismatch in de pack. Or a bad motor. ditched both and repaired the battery pack.

since then had another throw off. No proper record unfortunately but found a burned antispark switch.

Thanks for the heads up :+1:t2:

Do you really need antispark when you already have DieBieMS? :roll_eyes: I would say no :roll_eyes:

of course not but my diebieMS had some issues, replaced it with simple bms and antispark switch

First I’ve heard of anyone having issues with a DieBMS. Hardware/software related or a bad BMS?

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Ok so I’ve been trying to have a chat with kugliss about this to try and analyse what’s gone on but in the absence of that here are the preliminary findings…

My anti spark was charred as was the enclosure foam that was touching it. Unbelievably the anti spark still seems to function normally. Kugliss thinks that something conductive found its way into the shrink wrapped antispark initiating the short and shutting off the board. This fragment would have been vapourised so who’s to say
what if anything did this.

What I’m trying to work out is if there is any chance that the burned anti spark is a secondary effect. Now bear with my idiocy here and put me straight where needed… if my battery became disconnected briefly and shut everything down could the speed I was going generate enough emf in the system to initiate an arc in free air across the anti spark and therefore the damage? I’m hoping the answer is a resounding NO! so that I don’t have to open up my extremely heavily wrapped and sealed battery and can apportion blame to the anti spark.

No matter whether it was the antispark or not you are still going to have to strip that battery heat shrink off and inspect the battery. If only for peace of mind.


Like I mentioned in DM problems was that something got inside anti spark case and shorted output to ground the trace on the left is output and right is ground and something managed to make an arc strange it didn’t vaporized track on the left (still can’t find my head around it).

So my assumptions that then shorted voltage dropped enough to shutdown power to logic and switch restarted to off state (consider as turn off power and plugged back in) but this small arc shouldn’t have caused it in my assumptions. Everything else on switch looks pretty good and if it works then I am don’t know what caused that burn.

The culprit in my thoughts is that power went low and it reset switch but I can’t figure out what managed to kill power to so low. (Also don’t know if its good to in future design make a change to keep previous state before power reset)

EDIT: Just for guys who compare their own switch this is first version of this switch and DIY. Design since then has changed later on…

EDIT 2: Regarding generating enough EMF to cause arc that would need few kV to make this happen but then everything would had fried…

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I’m bypassing the bms so that shouldn’t be an issue for me… @Kug3lis the main damage to the board is on the buzzer side where the ground plane got very hot over about 1cm2, I think the scorching on the fet side is from that heating. How about I send you the switch to diagnose?

Full autopsy completed and board up and running again.

No visible faults anywhere other than the anti spark. The buzzer was loose on the anti spark which may have created a conductive solder flake… who knows. The anti spark was compressed which added a slight bend to it which may have caused a crack in a trace… again, who knows?

Replaced the anti spark and made sure it was not squashed in the enclosure and all seems well… very nervous to push the speed now however!

I still get pain in knee and hip when I sit still for too long and have to walk…