HFI om flipsky 4.20

Has anyone tried to run HFI on the flipsky 4.20? I tried searching but had No luck finding anything :frowning:

Is it the Mini FSESC 4.20?

Does it have “470” gate resistors or “4R7” gate resistors? (the “4R7” ones need repair)

Yes I have run HFI on those successfully. You must keep “battery max” set to 25A or less whether using HFI or not. That’s the secret to getting good performance from them.


It works great but not all the time. Most likely the silicon lottery will tell if your ESC will work or not.

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It Will be a new one because I fried the last I had (see previous thread), but that one had the 470 resistors :slight_smile:

I plan to run about 25a phase current and 15a batt. Current max so I think I am well within the design boundaries here :slight_smile:
It is for my ebike running a bosch active line motor, so I Will contribute with some leg force!

Don’t get excited yet, it’s still Flipsky.

Roll the dice and see if the one you got is good or not.


You will have much better luck running on these settings than trying to push them.

Also realize the bolts are made from ABS (yes, really) so act like they are made from tissue paper. Don’t stress them at all.

This will likely be way too low.


You can get by with 35a phase / 25a battery on all 4.12’s


On my thane board which now has my FS 4.20+ in it, I’m running battery 22.5A/-12A and motor 50/-50 on generic 5065 motors with HFI with no issues now. Seems like the 6355s at high current was the issue.


The motor is a mid motor that tops out at around 100 crank RPM at 36v. The normal phase/batt current rules are kind of not appliccable because it Will run around 80 crank RPM most of the time due to gearing.
But if I have an issue, I Will try to look at the phase currents :slight_smile:

Thanks for the great replies. I think I Will order another 4.20 then. Even though the performance is not perfect, the footprint could not be better for my build.