SBEC input wire guage vs. heat

[mjp8081]

So I got an SBEC from HK that's rated to 40v, but the input wires seem kinda small(same size as ESC receiver leads) for the 32v or so I plan to connect (8S)

Does it matter that they are pretty tiny? Do SBEC/UBEC input wires heat up at all? Or because it's only voltage and not draw it doesn't really matter? I don't really like the way they press up against the capacitor either.

 

[torqueboards]

It's fine. What the UBEC does is bring down your 40v to 3.3v to power your receiver. The wire itself doesn't pass through the full voltage.

On the left, you can solder the wires to the pos/neg wires of your power. The other 2 pin side should go into your receiver/wiiceiver.

 

[thepronghorn]

Heating in a wire is a function of current. Specifically the power dissipation for a length of wire equals I^2*R where I is the current flowing through the wire and R is the resistance of that length of wire. The voltage does not matter.

 

[mjp8081]

Sorry, I know the output side is just 5v and I know heat is a normal byproduct of current, I just don't want melting and shorting out on the input side. I think if you run enough voltage through a tiny wire even without load, it can create resistance and melting of the insulation.

I guess what I'm asking is: Has anyone ever had melting or shorts running 32v through tiny wires like that on an SBEC/UBEC? Looking at photos of other SBECS online they seem to use thicker gauge input wires than on mine. Is this a design flaw on this model?

I suppose I could just rip it open and re-solder some thicker input wires on to the board, but that's kind of a hassle I'd rather avoid. Another question, I have standard regular solder and iron, do these RC parts use special silver solder or something different?

BTW torque, I did finally get all my parts together and I will post a build thread soon. Much thanks to all your responses, and this forum, I completely know how to build a board now! I did a dry run of all my electrical parts wired up and everything works great--those motors throttle right up. I just have to finish my motor mount then mount all the electrical parts.

 

[Gregory]

like thepronghorn said, its all about the current draw, and your ESC or receiver may pull 500mA? Maybe a tenth of a watt.

Even maxing out the BEC at 5A (if you had big servos) , you'd be lucky to generate 0.5W peaks of heating in the wires.

 

[torqueboards]

You'll be fine with the small wires. It's no issue at all.