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?
Wire Thickness, resistance and current rating
Thicker wires have a larger diameter and cross section area, thus has a lower resistance for the same wire length, and can handle higher current.
Each wire has resistance, and the resistance has to do with the material’s conductivity, wire thickness and wire length. Thinner => more resistance, longer => more resistance.
What happens if exceeding the current rating
When drawing more current than the wire can handle, it will simply start to heat up due to resistance, and eventually melt. It also becomes the bottleneck in your power system and could struggle to deliver the power to your ESC/motors.
Single-strand VS Multi-strand
Wires with higher strand count are more flexible and easier to work with than single-stranded wires. We strongly recommend using Multi-stranded wires in your quadcopter builds.
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 important when it comes to soldering as the insulation doesn’t melt or shrink back. And generally they hold up better in extreme environments.
What AWG wire should I choose?
Look Up Table
To choose what AWG wires you need, first work out what your quad’s max amp draw is, then look it up in the table/guide below. The current rating is the continuous current.
Here is an example guideline from an electrical manufacturer.
The following table is what I personally follow when considering the max burst current for a short period of time. Please note that current rating of a wire has to do with the actual material and quality, this guide is only an estimation for the copper wires I have experience with.
12AWG 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 wire gauge that is already installed on the existing component.
For example for a XT60 connector pigtail (the connection between battery 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 came with 18awg wires, then I shall use 18awg wires too.
This way usually works and provides the best reliability to your system. 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. It all depends on the material and industry standard.
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 use are normally designed with a much much higher voltage (e.g. hundreds of volts and higher)
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. Therefore, make sure to buy wires from trustworthy sellers.
Like wires, connectors also have current limitation, so you should choose carefully based on the application to avoid it becoming the “bottleneck” of your system. Here are the guideline – continuous and burst current.
- JST connector – 5A (10A)
- 2mm bullet connectors – 20A (40A)
- XT30 – 30A (60A)
- XT60 connectors – 60A (120A)
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