Known bad firmware versions VESC/UNITY [ SERIOUS ]

Use latest firmware. (That’s FW 5.1)

To mitigate the duty cycle limit bug / unintended feature, You want to set duty cycle current limit start to 85%, as @Athrx mentioned.

Then, if you’re using motors with temperature sensors, to mitigate the incorrect temperature filtering bug, you want to set your thermal limits to start at 75 degrees, end at 100, or maybe start at 85 degrees, end at 120. Basically you want the window between the 2 values to be larger than the default 15 degrees.


Triple point for duty cycle current limit start, NOT max duty cycle! Should be right under it

I say this because there have been people that stop reading after duty cycle and end up making their boards even more dangerous. If you need more guidance we’re in the noob questions thread to help


I’ve been bumping the duty cycle current limit start up from 85% by 1% each ride. 90% has given me no issues and I think I’m going to call it quits there since I have to be going ~45mph to hit that.

Every board is different, I had one that was having weird issues at 90%. Be careful and pad up when changing settings :call_me_hand:


I just found out that my FSESC 6.6 is running on 3.62 haha.
There even is no such setting in the VESC tool like “duty cycle current limit start” for this version. It works fine for me since 1500km, I might just stick with it. I do not have motor thermistors so no promlems there.

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On escs that are by good qc or pure luck within very good tolerances you can probably leave it at 100%
On any 2 controllers that have even 0.1v readouts that get worse under load, one starts cutting out before the other and shit sucks


Been 2 years. anyone know if the list needs updating?

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Firmware 5.3 throws ABS_OC faults and cogs when full throttling your board with wheels in the air. Not really a big deal, it just freaks people out

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got a good link for that issue?

So this hasn’t been updated in a while.

I hear there are other concerns with firmware 5.3 but I don’t know what they are to list them. Anyone got details? links to discussions?

I just use 6.2 on everything nowadays. No problems

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i think 5.2 used to have this designation. :smiley:

still useful to document the known problems.

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All remaining versions are great now. :smiley:

trying to exercise cunninghams law

To be fair, after my initial shitshow with fw6, i’ve been really happy with my 6.2 experience. Good experience with solos, and only a little so far but so far so good with dv6s

6.2 really has been my most trouble free vesc experience

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Firmware still flawed until vesc tool (on all platforms ) starts automatically reading settings when switching CAN devices imo.

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Knowing this bunch, you’re more likely to see Godwin’s law :flushed:

Having this issue on my shortie on 5.2.
Hadn’t ridden it much other than dog runs lately, but a spicier ride with a bud made this apparent.
Looking back, this probably caused a good crash I had couole years back.

Gonna go through all settings and most likely update FW.

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It’s is butt puckering to say the least.

Was this fixed on 5.3? Im reluctant to go 6.2 as i still enjoy having one board with auto-logging.

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Allegedly yes but I have not tested myself. Been telling myself to try 6.2 for probably a half a year now to set up HFI but it’s such a non-issue that I never devote the time.

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Could you set your input range to 0 - 99.9% instead of 0-100%? That way you won’t ever be at actual full power, and possibly not activate the bug?