Battery cables

[mosand]

Hi all
I'm assembling a Pilot RC 100cc Yak.
I have mounted the Smart fly eq6 right behind the rudder servo. This gives a clean arrangement, with easy access to the wing bolts. The batteries (2x 2400 A123, 1x 1200 A123) ends up inside the motorbox to get the CG on the wing tube. This leaves me with very long power cables (approx. 750mm).
Is this a poblem? Anybody with any expierience with this.
(I was planning on running 18 AWG silicone cable).

Anders

[JoeAirPort]

Use the Deans Ultra connectors and you should be fine. There's a small voltage drop per foot of that wire but it's not going to drop it more than a few tenths of a volt in a snap roll. Check out this voltage drop calculator. Enter #18 AWG wire, 6 volts DC, 2.46 feet and the current load. I get .486 volts at 15 amps and .324 volts at 10 amps...on one battery. You will never pull 10-15 amps from each battery. Maybe 7-8 amps from each. 8 amps is .259 amps so there you go. A123 is 6.6 volts and your receiver will always see 6.6-.259 = 6.34 volts. That's pretty good. Just don't use regulators.

http://genuinedealz.com/voltage-drop.html

By the way 750mm = 2.46 feet.

[mosand]

Thanks Joe.
Just what I wanted to hear.
The Deans connectors where allready in place.
The Smart fly Eq6 has a built in regulator. What voltage do You suggest I set this to?. I will run a Futaba 6014 reciever.

Anders

[JoeAirPort]

I'd run the highest voltage the receiver and servos can handle. Probably 6 volts? Your servos should see no less than 5 volts at the longest distance from your receiver under the highest flight load.

[mosand]

thanks Joe

Anders