Hi guys
Noob question: if i roll my board downhill with my focbox turned off by a antispark (PCB with button from esk8.de) will i then blow my vesc?
I mean, blown from the power generated from the rolling motor with no acces to allow regenerating the batteri, since the antispark is off.
I’m also interesting in this. Also I don’t get it where goes generated energy when you just cruising with no throttle pushed? I mean after you get your desired speed by pushing throttle and then just letting go throttle. So when we brake with vesc we charge battery, but what happens on free rolling with antispark swiched on? Where goes generated energy- also charging battery?
If you exceed the erpm limit (60.000 erpm) while going downhill with a board that is on you will likely blow your vesc.
Regarding your question… no I don’t think you will blow anything when going downhill because you pulled out the antispark, therefore breaking the circuit.
The board will turn on, the reverse current will charge the MOSFET’s in the switch and allow power to flow back into the pack.
Wait really? So if even an antispark switch is turned off, a reverse charge will turn it on and let power through?
That’s what I’m wondering about now…
If your “free rolling” then there is no energy generated. if your not accelerating or decelerating then i would assume all of the FET’s on the esc are off and the motor is basically disconnected so there is no energy to go anywhere. Also if you exceed the erpm limit but your not asking for any power then again it shouldn’t matter cause the motor is not connected.
Theoretically that is the way (as @chaka said) it works, because of the body diodes in the mosfets. I have not tested it myself so “theoretically”.
There is at least some electricity generated. If you spin your wheels by hand you’ll see the lights on the vesc light up.
So going down hill with no braking, no throttle applied, with turned on board- it still be charging battery?
going down hill with turned off antispark switch will not damage anything?
interesting . . .
If you dont exceed the limit. there was a thread recently that was explaining this. People there were discussing going down hill and passing 60k ERPM. I am not sure about the name maybe someone remembers 
So first Off, it seems correct to me that you risk to blow something if going downhill very fast, so I wouldn’t do it.
Second: why would you wanna Turn Off your Board via Antispark when going downhill? Because you cant break and therefore, you just end up with a heavy Board with no breaking.
To try to ansewer the other question, wich Ninja asked (as far as I understand, correct me of I’m wrong):
No where! Because when free-rolling ( No throttle, No Breaks) your Motor does not generate any current.
If you take your board and disconnect from power and spin the motor you’ll see the lights flicker on Motor generates electricity whether breaking or not Regen just channels that to battery
It’ll charge the battery when you brake. Be careful not to exceed the erpm limit though.
Correct (theoretically)
I see antispark led switch(light) turning on when just turning drive wheel by hand when board is off. So energy generates. I don’t want to go down hill with turned off board, i just want to understand what happens when cruising with no throttle, since i see that motor genarates energy just from spinning it.
Well you just explained what happens 
I don’t think it’s healthy for the vesc
Yes there will be some Energy generated, since moving Magnets (Rotor) over a Coil (Stator) induces current.but Not a Lot. That ist what you see and that ist correct.
I am probably oversimplifing but when you apply throttle, your VESC will control the voltage like so, that the created magnetic field in the stator is ahead of the Position of the Magnets in the Rotor, thus you Draw current (a Lot) and the Motor moves.
If the Rotor moves because you’re going downhill and you apply the Breaks, your VESC will control the voltage like so, that the created magnetic field in the stator is behind the Position of the Magnets in the Rotor, thus the Magnets try to slow down, they induce a negative Current .
You need the VESC turned on, even if you’re cruising with no throttle. The motor acts as a generator and produces a small amount of electricity. If the VESC is off, that power has nowhere to go. It can handle some until the caps are charged, but after that you can blow your speed controller. There are some threads on it on the VESC forums if you are interested
One spin of my wheel by hand with the VESC “off” is enough to power on the receiver, voltmeter, and Bluetooth adapter for a second
So, the real thing is that i have build a 4wd board, with a antispark in both ends. This will allow med to choose between fwd, rwd or 4wd by disconnecting the vescs.
Works like a charm at slow in my test environment… Then i thought - what happens at high speed with the disabled vescs.
For information this is hub motors 70 KV.