Are you running all beta testers on the Little FOCers or are you planning a run of Serious FOCers after this one?
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I would also be interested in a Mother FOCer for an eFoil build 
Serious FOCer might work as well
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Well my plan is to crank out these beta units so field testing can start. While thatās happening, Iād like to start the design of the Serious FOCer. I already know the direction I want to go for that one.
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What specs are you looking for in a controller for efoil?
Tbh I am a total eFoil n00b. I am most likely going with the FS 65161 motor, which can go up to 20S. Iāll probably make a 16S battery pack. Most builds seem to be 12S and reliable, so 16S seems like a reasonable compromise between reliability and āpushing the limitsā. It will be a P42A or a 40T pack with enough amps output to bake the motor.
So I suppose 16S is a requirement. Your 5kW spec in the first post looked good and it sounds like something that might work for me. I will have water cooling available for the ESC, so it would be great if the ESC would have a nice mechanical interface for cooling. I donāt really care about the form factor of the ESC. PPM input and UART are must-have.
And if someone finds that 20S is amazing for eFoil before I start my build, I might do that instead of 16S.
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Most people arenāt going much higher then 14s on efoil right now, most are at 12s due to ESC availability. There was some concern about zapping yourself in the water if the battery case filled with water much above 14s. I havenāt dug into that my self, though.
I am running 12s right now on a 120kv motor and a flying rodeo prop with a ARC200 esc. Works great! From what I see other people doing, pushing it up to 14s seems like it still is in the sweet spot. Next build Iām shooting for 14s.
Current wise: Iāve seen on peopleās builds between 70-150Amp start up to get on foil then 20-50 amp cruising on foil.
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Thanks, great input! I will not run in salt water, so that might help with the electrical side. Seems like 14S or 16S will be the design target then.
In theory freshwater is worse for getting zapped: https://www.webmd.com/first-aid/news/20190722/electric-shock-drowning-silent-killer. All those deal with 120Vac or 240Vac, canāt find much info on DCā¦
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Interesting, thanks! You learn something new every day.
Doing thorough tests and analysis on one of the beta units.
Thermal performance seems pretty good. Takes 1 minute and 40 seconds to hit thermal throttling in 25C still-air at 75A. Also only using the smaller heatsink that Iām evaluating (the one that can accommodate a fan and not get too tall)
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The trick is realizing stupid is in everyone.
And Fessā dunning kruger corollary, if you donāt know that youāre stupid, Then youāre even more so.
thus I agree. trying to stop it is futile. 
[ EDIT: Oh damn. that was a year long bump. sorry I was being stupid. ]
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Just tested with the fan. It buys another minute before thermal throttling. so 2 minutes 40 seconds.
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now test it in direct sunlight 
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Well Iām in Texas. Thereās plenty of that around
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Test it in a unicycle going 20 mph jumping a 10ft gap.
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Thatās what I have you for 
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UPDATES?
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Iāve got the beta units in various levels of completion. My wife and I put about 8 hours into them this weekend. Weāll be working on them with the intent to start shipping some out by the end of this week and ship out the remainder next week.
Doing this beta unit batch is definitely helpful in finding out how I want to go about production.
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Are the capacitor-resistor pairs above each phase output snubbers?
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