Wire gauge, current and connector

[lsutiger607]

I am using a 3S 5000 MAH battery to power my electric motor. The battery came with 8 gauge wire and 5 mm bullet connectors. I want to replace the connectors with XT 60s. However, the wire gauge seems to think to accommodate these connectors. Is there a soldiering trick I should know? If I do manage to get an XT 60 on this wire gauge could those connectors handle a high amp draw?

 

[Craftydan]

Are you expecting to draw much more than 60A continious? The better versions of it are able to handle a bit more, but many of the cheaper knockoffs will struggle at 60A, and can get quite warm.

If yes, you might want to step up to a larger connector, like the XT-90.

 

[whiskeyjack]

Much will depend on the "C" rating. If your battery is 20C then it will put out 100a. Current flow creates heat, heat damages insulation be it the wire or connector. If you base your connector size on the "C" rating you can't go wrong.
"XT60"s may not tolerate that kind of current for very long until they start breaking down. If the connection shorts you got a problem!
Wire size is also important. You can go larger but never smaller. Smaller wire will act like a resistor increasing current and heat. Just remember that wire gauge is backwards, the smaller the number the larger gauge it is. For example; 12 is larger than 14, 6 is larger than 8 and so on.
Build your power system to withstand the max current your battery can put out which would include the ESC. The motor will draw what it needs from the "system", be sure it is up to the task

 

[Tritium]

8ga wire will not even begin to fit in an XT-60 and as others have said it's current rating is too low also.

Thurmond

 

[Darren]

How many amps can a jst connector (20 gauge) handle? I keep hearing about 7 or 8 amps but I see people running them 12 amps and above. I'm hesitant to use jst's with a 2s battery and turnigy d2826 with 7 x 5 prop.

 

[whiskeyjack]

Hi Darren, what kv is your 2826? Turnigy is quite good at recommended prop and ESC's. It is difficult to estimate what the current draw of a motor will be if you don't know what the kv is. I think that 20ga with silicon insulation could handle a fairly high current for a short time (maybe 12a) but not for long, 10 seconds? Please provide a little more detail, maybe we can figure this out. WJ.

 

[Darren]

Its a 2200kv. I am using it on my caipirinha. I see other caipirinha flyers using jst's but with the stock motor that is 2000kv. I think the stock motor can pull up to 18 amps.

 

[lonewolf7717]

2s with the 2826?? interesting, either way the Turnigy is the same motor as the popular RCTimer 2826-6 and that was a 30amp motor...believe 35 max. Question, why 2s on a 7x5? The typical setup for that motor and a very good one mind you is 3s running a 6x4 or 7x3. 2s systems make for poor fpv efficiency, you will be losing out on more that 100watts of potential power from that little motor.

see Ed from ExperimentalAirlines documentation on this motor
https://docs.google.com/spreadsheet/ccc?key=0AtSZzrsraF1-dDJzNGVEMnZnRzNzMkJab2dfRjlxMnc&usp=sharing#gid=0

 

[lonewolf7717]

btw, jst....10amps MAX. not even sure if personally i would push that.