Has anyone tried this SSR? https://www.mouser.com/ProductDetail/Crydom/D1D100?qs=ftmCDQnBrlNIkJ8oaSttng%3D%3D
Or this one? https://smile.amazon.com/100A-Solid-State-Relay-SSR/dp/B00KO46YCU?sa-no-redirect=1#customerReviews
Both of those can handle 100A. The first one is tiny compared to any anti-spark you’ll see and can handle 100v. It does require some circuitry to use them in a skateboard but form factor would still be comparable to a anti-spark switch.
I think a good place to get ideas from would be those ebay escs. The power buttons on those work flawlessly.
EDIT: Iv’e been thinking about this topic for a bit now and I have thought of a potential design for a new Anti-spark. DO NOT GET YOUT HOPES UP THIS IS 90% LIKELY NOT TO WORK and has probably already been tried or is how the current switches are made. I will update you on how this goes once I have tested my idea. Oh and I am still at high-school so I guess that gives everyone even more faith. lol
Any help in solving this problem would be be appreciated and I can see what can be done to help with funding 
All I know is in every case, the FETs get stuck in the open position and never close again. What causes this is a mystery to me.
I’m actually taking a class that focuses on the physics behind MosFets right now, I’ll review the notes and come up with an explanation as to why this might happen.
By FETs stuck open, do you mean they’re stuck as an “open switch” and thus the anti-spark is always in the “off” position?
Pretty sure he means closed position, well thats the most common thing Iv’e seen happen
Nothing special. Just took the Fechter’s 
design with matched components:
I used this N-channel fet and these diodes. I used only two fets in paralle though. 
You mean Fetcher design…
I’ve been told to think of the fet as a gate. The more the gate is open, the more electricity comes through. And thus when you get your batteries full voltage through the power switch, the fet is open and electricity flows.
If I’m wrong, please correct me
None of this is required if you get yourself a BMS with a precharge function.
Please explain to me what is a precharge function? My solution to balancing is simple: A balancing board. Let the switch turn the board off and on and the vesc’s to limit current and protect from under voltage.
Exactly what the VESC anti-spark switch is. The photo posted by ZackoryCramer 4 comments above this one is titled “inrush limiter”. The gist is it controls current over time such as 1 millisecond to prevent destroying sensitive electrical components. Now here the funny thing, an appropriately sized capacitor fits this category of controlling current that people in the RC community just use more capacitors and problem solved for preventing ESC destruction. But we have the electric skateboard with caps near ESC. The MOSFETs on the BMS does the job of controlling current output in the beginning.
Side note. On my setup, my BMS has this feature and I just use a 50 amp LP J Case Fuse. It sparks, but it’s contained within the case.
I understand you want an option as simple as a flick of the switch, but to increase the reliability of the circuit someone has to run a SPICE simulation to isolate the problem with the mosfet. The Zener diode, capacitor, and resistors are the least of your worry. I remember some post saying there is a specific type of Mosfet that can handle this Other than it being known as an N-Channel Mosfet.
Flick this switch…
AS150 antispark bullet…in a switch… its effectively a loop key you can’t loose…
PS it’s the size of one 18650…
Can we see how that fits into your board/build for design perspectives ?
Don’t have it installed yet.
But you could just “add another cell” to your battery pack size and just attach it to the end of your battery, redesign the panel part of the switch so the hole is only as big as the switch opening. And basically have the antispark built into the battery with a mechanical slide underneath the bottom side of the enclosure.
From what I recall there is a voltage drop across the relay. Also you’ll need to find an alternative power supply to turn on and off the relay.
I bought one, then gave up and went back to XT90 antispark loopkey.
Post BOM! Post STL! Post schematic! =P Where’s the resistor that limits the current?
The saturation of the FETs is what limits the current as C1 charges up via R2
Oh, I thought you were talking about @ZackoryCramer’s schematic, sorry
…With 5 Hours into the thread:
@Deckoz has a good design, but no details. @chuttney1 has stunned with his “just add more caps” observation and @ervinelin has disqualified solid state switches, and soooo…
@ZackoryCramer has the lead. Because he’s special =P
Can @Deckoz make a comeback? Will we ever solve the mystery of the faulty anti-spark switches? The thread is just getting started, folks!
So my 6s lipo spark inside my charger. So to stop that I just plug in 3s for a second then 6s.
Any way to precharge the caps with a lower voltage.
