View Full Version : Wiring Lengths

12-29-2006, 04:52 AM
I would like to hear from a CC rep about maximum length of wiring from LiPo Batteries. to ESC. and from ESC. to brushless motor. Voltage say 22.2 and Amps 40, just for an example. It may be a dumb question but there are so many varying opinions and old wives tales out there. I need a quality answer.
Regards, Jack,:)

12-29-2006, 06:20 AM
I doubt very much if you will get a hard answer. There are just toooo many variables.

On the battery side - one of the biggest is the power draw on your system and how hard the lipos are being pushed. The bigger the voltage drop on your packs under load, the larger the voltage swing at the input caps and the higher peak voltages they will see. Conector quality and wire size have a roll as well.

On the motor side - the biggest item is the quality of the motor. Second is probably how good your contections are and on the size of the wire and if/how they are twisted or not.

Some setups have problems even with short wires while others with almost the same equipment get away with very long leads and have no trouble.

If you need to run long leads - On the battery side, your best insurance is to use packs that can very easily handle the loads. Dont push the packs at all. Make sure that peak power draw is only a small % of the max "C" rating. Check to see how much the voltage drops under load - keep that number very small. Make sure your conections are good and use large gauge wire. You can also add additional low esr input caps to help somewhat.

On the motor side - dont use cheep Chinese motors. Solder the motor wires direct to the esc leads.

Finally - keep your fingers crossed :D



12-29-2006, 06:23 AM
Forgot one more item. If your going for long leads - use an ESC rated well above the max voltage your going to be using. Its also a good idea to de-rate the current as well, but voltage is far more important.

You said 22 volts above. The P80 for example is rated for 6S lipos, but if your going to use long leads on the battery side you could easily be generating large voltage spikes. You should go to the HV85 or drop the input voltage.


12-30-2006, 05:25 AM
Larry thanks for the reply, it makes good sense, common sense. It's a good answer and I'll use it in my Vance Vancouver He219 uhu. I've also found it does'nt hurt to use an oversize ESC in general.
thanks again, Jack

PS: I'd still like to hear from CC

12-30-2006, 06:09 AM
I've seen that same question asked at least two dozen times over the years and never a hard answer from Castle.

You might get lucky tho :D


Joe Ford
01-05-2007, 02:59 AM
12" max on the battery side. 7" on the ESC already so only 5" left for wire coming off the battery and any extensions. If you have to extend any wires ALWAYS extend the motor to ESC wires. Extending the battery side induces voltage ripple and kills controllers. The worst that can happen extending the motor side is the motor fails to start...if this happens, resolder all connections. If it still doesn't work, try another motor. Do not keep hitting the throttle as the current will build up on the MOSFETs and can potentially blow the controller. I've seen as much as 24" of wire extension on the motor side. ;) If you absolutely HAVE to extend the battery wires make sure the packs you are using are FULLY capable of supplying 1.5-2x the current you will be drawing. DO NOT trust the lipo manufacturer specs...if it says 20-30C, treat it as a 10-15C and use packs in parallel accordingly...better safe than sorry.

01-05-2007, 06:08 PM
Joe, thank you for stepping up to the plate. I will use the info as a guidline for wiring my models.