AWG stands for American Wire Gauge, which is a wire gauge standard based on the diameter of the wire. The diameter of the the wire chosen for RC models and quadcopters is important. It determines how much current should go through it and can go through it safely without failing.
What Types of Electrical Wires to use for Quadcopters and RC?
Thicker wires have a larger diameter and cross section area, and thus can handle higher current. Wires with higher strand count are more flexible and easier to work with than single-stranded wires.
Also, using silicone insulated wire is the best for RC applications. Silicone insulated wire is much more flexible than the standard PVC insulation (great as multirotor frames and components keep getting smaller). It’s lightweight and has a wider temperature range that can handle more heat, which is nice when soldering as the insulation doesn’t melt or shrink back near as much. And generally they hold up better in extreme environments.
When drawing more current than the wires can handle, they simply start to heat up and eventually melt. It also becomes the bottleneck in your power system and struggles to deliver the power for your motors.
What AWG wire should I choose?
Look Up Table
Simply work out what the maximum amp draw is, and look it up in the table below. The current rating is continuous current. The amp requirement can be increased for our hobby since we choose wires according to peak current (at 100% throttle, which doesn’t normally last longer than a few seconds in most cases from my experience.
Here is an example guideline from an electrical manufacturer.
The following table is what I personally follow if when considering max burst current for a short time. Please note that current rating has a lot to do with wires quality and material, this guide is only an estimation for the copper wires I have experience with.
13AWG Wire - 130A 14AWG Wire - 110A 16AWG Wire - 70A 18AWG Wire - 45A 20AWG Wire - 27A 22AWG Wire - 17A
When connecting 2 wires, the max current you can run through them is always limited by the thinner wire. So when you are connecting 2 components, you should always match the gauge wire that is already installed on the existing component.
For example for the XT60 connector pigtail (between XT60 male connector and PDB), I always use the same gauge wires on the battery discharge lead. If the batteries I am using have 14awg wire, then I should use 14awg wire for the XT60 pigtail.
Another example, if I want to extend the ESCs power wires, and they come with 18awg wires, then I shall use 18awg wires too.
This way usually works and provides suitable wires for the components you are using. You may use thicker wires, it won’t bring any benefits but extra weight.
Why current ratings are different from different sources?
You might find different standards and current ratings from different electrical wires manufacturers. They represent the maximum current for which the heating and the losses are below a specified level. Firstly like I mentioned, wires could be made from different materials thus the difference. Secondly, each industry has different standard and specification. For RC quadcopters, the above table should be sufficient.
Does Voltage matter?
Voltage is not that important for RC applications, since the voltage range we deal with are normally within 30V. Note that the wires we used are normally designed with a nominal voltage of 600V and tested at much higher voltage e.g. 2000V.
Some More Tips
The chart above is based off of decent quality copper wire. Cheap, low quality wire might be made of brass or aluminium instead, which could have a negative effect on the max current it can conduct and handle. The consumer would not know this effects unless technical electrical tests are done on the wires. Therefore, make sure to buy wires from trustworthy sellers.
As mentioned above regarding “current rating bottlenecks” in the wires itself, limitations can also take place in the attached connectors. As an example, 22 AWG wire might good for up to 15 amps, but the connected JST connector might be limited to 5-6 amps.
More Info and Discussion
We have a similar topics on the forum if you fancy more information and discussions.
- May 2014 – Article created.
- Apr 2017 – Article revised.