Battery wires for the FT cruiser

hdoug5

Junior Member
hi all
i'm having serious problems making the wiring harness for the battery for my cruiser I've tried 10 ga wire 14 ga i'm at my wits end, please tell me 16 gauge wire will work and not burn something up or else ill have to sub out the work so I can fly my plane
thanks in advance
Doug
 

earthsciteach

Moderator
Moderator
Do you mean the wiring from the battery to each esc? If so, just find a wire that is about the same gage as the esc wires and you should be fine. You won't be pulling a huge amount of amps through them.
 

Craftydan

Hostage Taker of Quads
Staff member
Moderator
Mentor
Doug,

You're going the wrong way if you think you're burning out wires from current. Wire size/current capacity goes down with rising gauge (AWG 16 is *smaller* than AWG 14).

AWG 10 is on the HEAVY side for most of what we do here. It sounds like the problem is less the wire as what/how it's connected. I'm wondering if something is mis-wired or uninsulated contacts are shorting against something in flight.

Can you give us pictures of your setup? Pencil diagrams of what's connected to what? If you can't, the place it burns out may not be the source of your problem, but the problem is probably be "electrically nearby".
 

Tritium

Amateur Extra Class K5TWM
Crafty my impression is that he can't get it soldered because the gauge is large.

Thurmond
 

Craftydan

Hostage Taker of Quads
Staff member
Moderator
Mentor
Ah. hmm. Still don't get that from reading, but you're probably right.

In that case, good answer, Teach.
 

Tritium

Amateur Extra Class K5TWM
He says he tried the bigger wire and he is afraid if he goes smaller the wire would burn up because of too many amps.
That is my interpretation anyway. :)

Thurmond
 

hdoug5

Junior Member
Tritium is right "im trying to make the harness" to go from battery to both esc's but the wire I got from hk is either 10 ga or 14 ga and either way both are too big for the connectors and my soldering skills are sorely lacking.
I just want to make sure if any one out there is using 16 or 18 ga wires they don't have an overheating problem caused by the smaller wire, I would hate to see my new plane go down in a blaze of glory because I didn't do it right the first time.
I really appreciate the feedback you guys are the best
Doug
 

Craftydan

Hostage Taker of Quads
Staff member
Moderator
Mentor
Doug

Thanks for confirming, sorry I was muddying the waters.

I know this isn't directly answering your question, but . . . Have you seen the video FT did on soldering THICK gauge wire? they did two, it was the second one w/ David. Good tips if you haven't seen it.


Assuming you're using one of the suggested motors, the NTM tops at 18A (before the motor burns out). Checking an AWG chart (many others available via Google, most identical: Wire_Size.htm), you have two current colums - chassis and power. Difference is how the wires are run (not how they're used). In "chassis" -- best case -- the wires are individually run, so they can dump heat in all directions, and don't gain heat from neighbors. In "transmission" -- worst case -- they're run in a bundle, so they can't offload heat well.

AWG 16 is rated at 22A in separated (chassis) runs. AWG 18 is rated at 16A.

These tables are conservative, so AWG 18 *may* still work, but you're pushing it. AWG 16 should work, but don't wrap it tight in foam -- let it breath if you can.
 

hdoug5

Junior Member
thanks crafty dan
im running 30 amp esc's, yes I've watched the videoes they are very informative but I really don't have the patience it takes and rather than do a shoddy job with the big wires I want to opt for smaller wires that will carry the amperage and not overheat, I understand about wires being close together will share heat buildup
 

Craftydan

Hostage Taker of Quads
Staff member
Moderator
Mentor
Glad I've finally answered the right question!

Can't fault you -- I hate soldering low gauge wire too. It's why man invented wirenuts! (just don't use them on your plane ;) )

Those AWG charts can be handy in the future, now that you know what they mean by chassis and transmission. I use it occasionally, but mostly for remembering how much I can push down a AWG 26 (or finer) wire for some widget. It's good to have a feel of what isn't a good idea before I burn something up!
 

Tritium

Amateur Extra Class K5TWM
It's why man invented wirenuts! (just don't use them on your plane ;) )

I have used them on several craft and quite successfully I might add. Apply wirenut, shoot full of hotglue. Done!

If upon inspection you find hot glue has migrated from a wirenut you know that connection has a problem.
OF Course Solder is the best permanent solution and I might add I fly at NO public locations.

Another solderless method is use small lengths of copper tubing as wire crimps.

Thurmond
 

DDSFlyer

Senior Member
This part was ridiculous...I ended up getting some 12ga wire to solder but it barely fits the XT60 connector. I would recommend 14ga as the preferred sidle for this project.