Safety with eFoils


If your ESC doesn’t have a BEC built in, then you need a UBEC to power your receiver.
The Oset brand magnetic switch I am using comes from a 48 volt bike. So I assumed it would be suitable, considering the small current draw from the receiver.


What is your magnetic switch switching? Power to the receiver?


I à bec to my contrôler to connect thé receiver
My contrôller has a poser switch
But i dont Know how connect dead man After my Waterproof breaker
Dead man has only small wires and i m not sure it s support batteries intensity !
Do i change wires and connectors ?
Havé you a réally picture With exemple connexion ?


@g.gregory8 my magnetic switch is going to be connected to my UBEC which powers the receiver. I’m not sure if this is the correct method, I was hoping for suggestions from other builders too.
@giloris I don’t have pictures as I’m still in the planning stages too.


My input relay is 44.4 V (2X6S), i install a waterproof breaker but i dont know how installing my dead man switch . Did i need a relay ? , how to connect it ?


What does your ESC do if you unplug your receiver?
Your BEC-Killer does only kill the receiver, not the motor nor the ESC.
So if fail-safe at ESC does not turn off motor this will not work.
Better and clean solution is anti-spark-switch: e.g. this one
which specific you use is depended on your motor-battery combo. If you run more than 60V you have to watch out and depending on the amps you want to drive your motor with, you might need multible fets.


I Want install this safety if i fall to stop motor



@Giga my ESC has throttle signal loss protection.
So by cutting power to the receiver should cut power to the motor.


Hi, I’m interested in this sensor, do you still have the link to find it?

Did you use this sensor? I’m worried that it might not be really “waterproof”.


Has anyone used/tested a circuit breaker (CB) such as this? I had a thought to use this circuit breaker also as a switchable dis-connect. I.e I will trigger the circuit breaker test button with a servo to break the circuit and also use the same servo to reset it.

The intention is to simulate having a contactor, until I find a suitable contactor solution. I have a teensy in the loop controlling the ESC speed, so this can also control the servo to trip and reset the CB. If the lanyard is pulled then I will trip the CB. Obviously this isn’t super reliable adding a servo into the loop.

I haven’t actually tested this circuit breaker yet, just trialled the trip / reset with a servo.

Any thoughts on this idea?


For 3000A@48v interrupt capability those are quite cheap, good find. I wonder how they work internally and how much power loss occurs at 100A.
For the servo idea, I like it but that would be to much mechanical stuff to figure out for me. Maybe if you open it up, a way to acuate it electricaly could be found. Edit: Like @MaxMaker says below, there is only a bimetal sheet inside. I found a video teardown. Does not look confidence inspiron to me.


This still works perfectly, expensive tho

Ssr relays are prone to generate heat, which is not ideal.


I looked at them. Very cheap. Some say „waterproof“ but I don’t see how they can be. Inside are two metal plates that deflect to create contact. Clever mechanism, but not very accurate and prone to errors due to cheap manufacturing. Check out some videos on Youtube. They break all the time.


Check out Albright relays. Plenty on ebay for forklifts.


Thanks for the contactor/relay ideas guys. The Kilovac look like the best solution, just pricey. The Albright ones look reasonably priced. Have you tested yours yet @MaxMaker?

There are alot of these style circuit breakers out there all with ratings up to 250A. But I agree they just don’t look beefy enough.

What is everyone using to fuse there system then? Standard glass fuses?


I tested it with a bench power supply. Works like a charm with 12V and 0.7A.


Quick one : is carbon fiber an electricity conductor, and if yes, then should we be really using it ? Same for cooling aluminium plate to cool down the esc (that said I love carbon fiber looking and aluminium plate cooler idea :slight_smile: )



Yes they are, but its not just about weather they are conducting. It is more about where they are conducting too. The current wants to flow from positive to negative, so it needs a circuit to do that. Hopefully your finger is not part of the circuit. If your heart is part of the circuit, that could be deadly.


This was just posted on the forum, could be a good solution, but we don’t know anyone who has used this yet Complete power switch with magnet shutdown: Another power switch


I saw that a while back, there are video’s of how to use it on youtube.