Choosing Electrical Wires and Battery Connectors for Quadcopter

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.

In this article we will explain why and how the thickness of the wires can affect the performance of your drone, and what properties in a wire we want to have to use on a quadcopter.

Finally, I will recommend some places where you can get these battery connectors and wires from.

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 wire = more resistance
  • longer wire = more resistance

Wires with more resistance will cause more voltage drop and delivers less power.

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.

Insulation Material

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.

Are red and black (or other colour) wires different?

No, they are the same wires just different, colour, you can use any colour you want. But conventionally we use red for positive power and black for ground, so it’s easier to visualize what is what. We strongly recommend you do the same.

Colour wires are often used for signals.

What AWG wire should I use?

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.

current draw wire awg thickness diameter table chart

Example – Wire AWG and Current ratings

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 - 160A
14AWG Wire - 120A
16AWG Wire - 80A
18AWG Wire - 45A
20AWG Wire - 27A
22AWG Wire - 17A

Using appropriate wire size can minimize the voltage drop and power loss due to resistance, and the risk of overheating the wire.

Avoid Bottlenecks

When connecting 2 wires, the maximum current that can be passed through them is always limited by the smaller wire. So when connecting 2 components, it’s always best to match the wire gauge that is already installed on the existing component, and not to use smaller wires.

For example for an XT60 connector pigtail (the connection between battery and PDB), I normally use the same gauge wires on the battery discharge lead. If the batteries I am using have 14awg wire, then I would use 14awg wire too for the XT60 pigtail.

Another example, if I want to extend the ESCs power wires, and they came with 18awg wires, then I would use 18awg wires.

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

Wire Quality

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.

Connectors Rating

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’d like to learn more about this subject and like to comment.

Where to buy LiPo Battery Connectors – XT60 & XT30

XT60 Connectors

XT60 14AWG Pigtail if you are too lazy to solder your own…

XT30 Connectors

Where to Buy Silicon Electrical Wires

12 AWG (for XT60 pigtail, high performance 5″ racing quad)

14 AWG (for XT60 pigtail, medium power 5″ racing quad)

16 AWG (for XT30 and XT60 pigtail, low power up to 80A burst)

18 AWG (for XT30, ESC power, and motor wire extension, up to 45A burst)

28AWG (for signal)

Edit History

  • May 2014 – Article created
  • Apr 2017 – Article revised
  • Nov 2017 – Added product shopping options

25 thoughts on “Choosing Electrical Wires and Battery Connectors for Quadcopter

  1. Pinak Oza

    Very nice and informative article. Thanks for sharing this.

    My quad DH410 acts weird for what I need your advice. When I first built it, it was about 1400gms (with no gimbal and camera) including 4000mAh 4S lipo. It used to give about 11 min of hover. But then I decided to slim it down. I made many changes in wiring and connectors esp and successfully reduced it’s weight by 100-120 gms. Mainly I removed all bullet connectors from each and motor and also reduced the wire gauge of all 4 Sunnysky X2212 980kv motors from 18 to 22.

    Now Pixhawk gives low battery alarm in just 30sec of flight ending up in RTL. BUT with 2200mAh 3S battery, it still flies for 9 min (total 950gm wt). With 4000mAh 4S, just 30 seconds. I have 2 batteries – 4S 4000mAh, and with both it behaves same. So can it be a gauge of motor wires triggering RTL? Telemetry shows voltage literally crashing from 16.4v to 13.8 in few seconds. Please advise; thanks.

    Reply
    1. Oscar Post author

      I think the problem you described is caused by something else though, try swap the wires back, you shouldn’t really change out original wires unless they need to be upgraded to larger gauge. Also 4S is going to draw more current than 3S, so you really shouldn’t use smaller Awg wires.

      Reply
  2. Seth

    Hi Oscar I have these emax Bullet 30A esc’s gearbest.com/multi-rotor-parts/pp_603577.html what wire do you think the red and black ones are?

    Reply
  3. Dave

    Hi Oscar,
    What AWG wires would you recommend for the following:

    [1] from [Flight Controller] >>> [KISS ESC 2-5S 24A Race Edition]?
    [2] from [Battery 3S/4S] to [PDB]?

    Thanks
    Dave

    Reply
  4. Markus

    Hi Oscar,

    I have these ESC’s
    (banggood.com/de/DYS-BL20A-Mini-20A-BLHeli-ESC-OPTO-2-4s-for-RC-Multicopter-p-975798.html)
    and want to know the cross-section of the power cables (red and black).
    Do you know the thickness of these wires?!

    Thanks in advance for your help!!!!

    Markus

    Reply
  5. Mathijs Groothuis

    I have 20A littlebee’s and 2300KV E-Max. Should I then go for the theoratical values of:

    4 X 30 A (Littlebee’s Burst) which makes about 120 AMPS, needing 12 AWG?

    Still need to buy batteries, but can’t find the AWG size of them (looking on HobbyKing)

    Reply
    1. Oscar Post author

      nah just match the size of the cable with the batteries you are using, and you should be fine. For most 1800mah 4S 65C for example they normally use 14Awg.

      Reply
      1. Bruno

        Oscar i noticed many 4S battery are now coming with 12 AWG wire (Lumenier 1300mAh 4s 75c LiPo Battery (XT60), PULSE Graphene 1550mAh 4S 14.8V 95C Battery w/ XT60, Thunder Power Adrenaline Series 1300mah 4s 80c, Tattu etc, etc, etc) Should i still use a 14 AWG as usual or i should upgrade my battery pigtail?

      2. Oscar Post author

        If you don’t mind the few extra grams, I think it’s safer to use 12awg :) But I don’t think 14awg would cause any problem either :)

  6. Erick Cruz

    Thank you for this useful article.

    Just wanted to ask, I’m planning to tranfer my existing quad to a 500 frame and would need to extend the existing wires I have from my 2212kv motor to my 20A ESC. I had trouble finding 20AWG wires and only found 18AWG wires. Would there be any specific issues I might encounter if I hook those up to extend the existing wires?

    Looking forward to hearing from you!

    Reply
    1. Oscar Post author

      apart from more weight, it’s absolutely fine running thicker wires.. or combining different awg wires, shouldn’t be any issue.

      Reply
  7. Russ

    Hi Oscar,
    The ESC KDE 35A might not be the correct esc. Typically for the motors that are being used the KDE 55A are recommended.

    Reply
  8. Chris

    Hi Oscar,

    Thank you for writing very useful and informative articles. They have certainly helped enormously with my quad build.

    I would like to ask you advice in regards to wire type when connecting the ESC signal wires to the FC.

    I run BL30A ESC (Opto). I plan on replacing the signal and ground wires that are on the ESC’s with just a single signal wire. (The ESC’s will be grounded to the PDB). I would like some advice if possible in regards to wire type. Should I run stranded bare copper wire or tinned copper wire?

    I have read that tinned copper wire provides extra durability to the copper wire but I am wondering if bare copper provides better signal performance than tinned?

    Also what AWG do you recommend using for the ESC signal wire, 26AWG? or thicker?

    Thanks in advance. :)

    Reply
    1. Oscar Post author

      Hi Chris
      Any electrical wire should be fine. 26awg is perfect, signal wire doesn’t carry much current, and it’s usually fairly short anyway.

      Reply
  9. moosestang

    So i’m having an oscillation problem on a small quad i built with 18a spider esc’s. The thing is small, 141 grams with battery. I’ve tried every pid combination i could thing of, tpa, etc, etc, but still it oscillates at full throttle. Googling it i found someone that supposedly fixed their oscillation by changing to a higher gauge wire for the escs, so i looked over all my wires and the battery wire is 18awg, but my jst power wire is 22awg. I’ve ordered some 18awg jst connectors, but i wonder if this bottle neck in the power distribution can cause such oscillations? I have the esc’s soldered to a pdb.

    Reply
    1. Oscar Post author

      anything is possible in this hobby :D but 22awg wire for the main power cable does sound small, and when ESCs might not get enough power at high throttle and start to struggle.
      best thing to do is check your motor/prop combo and see how much current they draw to work out best awg wire to use… otherwise you can just use same awg wire on the battery.

      Reply
      1. moosestang

        sorry, it’s actually 20awg, but still it’s a bottle neck. it could be a lot of things i know. I end up replacing the esc’s with dys 20a just to rule them out i’m sure.

  10. Zewill

    Hi Oscar,
    I have a question regarding the jst connectors. I have a 3s lipo 1500 mah 35c with xt60 connector with 14 or 16 awg. I would like to do an adaptor for jst but my jst wires are quite fin (22 awg). Would that be problematic? What could happen? It’s only to power a light plane so 1 engine esc and 3 servos! Thanks!

    Reply
    1. Oscar Post author

      depends on your max current draw through that JST connector? For around 10A your 22awg wire should be fine… you might get away with a bit higher current going through it, but it might start to heat up.

      Reply
  11. Jo

    Great article and very informative!

    I would love to have your help with something which is related to this article.

    My X8 octocopter won’t lift off when I add more payload to it. Right now the AUW is 15lbs (with no gimbal, cameras or FPV accessories). When I connect one battery it hovers fine but will only fly for a few mins, but when I add two batteries, in parallel, then due to the added weight it takes off for two seconds and lands hard as it starts yawing to the right.

    My power distribution board had 3.5mm connectors but changed them to 5.5mm Castle Creation connectors. Because of that I replaced also the bullet connectors from the ESCs end side to 4mm. I also upgraded the wire to 10AWG but even after doing all that I’m still having the same issue. Now the only connectors I haven’t replaced yet are the motor bullet plugs from the motors, as well as the connectors on the speed controllers to the motor side which are 3.5mm.

    The propellers I use are 15×5.5 T-motor equivalent.
    Frame: Gryphon Dynamics GD-X8
    Motors: KDE FX4014 380kv
    ESCs: KDE 35A
    Battery: “MonsterRC” 35C 6s 10000mAh
    FC: NAZA V2 (with low voltage alarm disabled)
    AUW: Estimated to be 14-15lbs without gimbal, camera or other components.

    Any advice would be greatly appreciated!

    Reply
    1. Oscar Post author

      sorry i don’t have much experience with multirotor of that size.
      but by the sound of it, it’s a power issue? could you upload a video in this group?
      facebook.com/groups/Copter.Fans

      Reply
    2. Alexander James Curtis

      I’ll answer it. That’s far too heavy a battery for the power being generated by those motors. 20,000 6s in insane. Try a 5000 6s at most

      Reply

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