4 AWG Battery vs 4 AWG Welding Cable

[Dave Beleskey]

Hi

I have an Outback FM60 and I have been trying to find some information on the best cable to use to go from the controller to the batteries. I have a run of 15' and will use the max I can on the FM60 which is 4 AWG. I have been reading and don't know whether to use 4 AWG battery or welding cable. Most places I read say the only difference is in flexibility. I don't know though...big difference in price, must be more than that. Any suggestions on what I should use ?

[Bryan Couch]

There's a thread I was reading over on the NAWS site, apparently the welding cable has a larger number of thinner strands in the wire compared to battery or household wire. The finer strands make it harder to get a good connection when wiring to batteries/bus bars etc.

This is just from internet research NOT first hand so it may not be 100%. :)

[Dave Beleskey]

That's what I've been reading also. The finer stands make the cable more flexible and easier to use when welding but a good connection is harder to get. I think I will just stick to the battery cable. It is a little more but worth it in the long run. I can find it locally here for $2.55 a foot, need 30' - 2 x 15' run.

Thanks

[Rob Beckers]

Dave, 4 AWG is not that thick or hard to work with. I'd just use regular wire, from the electrical supply store. Yeah, if you need a sudden 90-degree turn it can be a bit hard, that's what pliers were invented for (and once bent into shape it stays in that shape).

Fine-stranded battery (a.k.a. welding) cable is great stuff, but it is for 2/0 and 4/0 inverter cables and the like. I would be worried about clamping that under a regular screw terminal (those thin strands crush easily). It's for crimp-on or soldered lugs.

-RoB-

[Dave Beleskey]

Thanks Rob, I will check that out. Will the 4 AWG regular wire from the electrical supply store be stranded or solid ?

I'll check out HD and Rona too..

I do have a connection to make at the disconnect. I see what kind of terminal connector are available.

[Rob Beckers]

Dave, regular wire is stranded. Only time I've seen solid 4 AWG is for (bare) ground wire.

[Brian McGowan]

I have an FM80 (mechanically the same as your FM60) and I used #4AWG THHN. It works just fine.
Second picture from the bottom shows my system.
http://home.comcast.net/~bigvid/mysolar.html

[Chris Olson]

You don't need 4 AWG wire to the battery for a 60A controller. 6 AWG THHN in conduit works just fine.

Welding cable works fine for crimped or mechanical clamp terminations. However, if you plan on terminating it in screw clamp bus bars or lugs either a ferrule must be used or tin the wire.

[Dave Beleskey]

Well...got it all hooked up and everything is working great. Looks like it will be more than enough of a system for our needs. Thanks everyone for your help...
Dave