Is flexible welding wire okay

[cgtech]

Isn't "just good enough" good enough for me? Sure, depends on how picky you are for just good enough... Want "good enough", or "best I could do, and do myself"? I want (and make for my customers) as good as I can do. I only order materials to do the best I can offer. Welding wire, soldered copper terminals, and heatshrink when I'm done. I would hate to install, or hand to a customer any less. I even solder 6ga stock size cables if I had to do a "cheaper job" with all other stock parts. Not "space shuttle" good, but golf cart customers would never pay for that.

[BobBoyce]

Originally Posted by Stewbuntu

Very interesting stuff. It esp makes sense with the high amps out carts deal with. I read that copper pipe Flux is better for copper oxide as it's more corrosive.

So do you fill the connector with Flux, dip the wire in, crimp, then solder, but how do you get it hot enough inside the connector without melting the wire jacket, but hot enough to pull in the solder?

I need to try and find some videos on YouTube to see the color copper has to be in order to melt solder (plumbing type videos), I can't remember after years.

I put in a new ignition last night after I jumped it for a day, and we are loving our new cart. On the first day of it running we went out for breakfast and my wife giggled a lot while driving it. When she put it in reverse, drove all the way around a restaurant building, and crossed through some grass near the forest - she is like a kid :)

Plumbing flux is acidic. Not only does it eat though the oxide, it will continue to cause corrosion, after the fact. Use electronic/electrical flux, it is rosin based. I brush the flux inside of the lug and to the ends of the cables, insert the cables into the lugs, and heat the lugs with a small torch.

To prepare, I will split the cable insulation all the way around and pull it apart, sliding it back over the cable in both directions, prior to cutting the copper. It will compress into itself a fair bit. I trim it enough to full insert and leave a gap of copper strands exposed to apply the solder to. I brace the end of the lug against something solid and heatproof to keep the lug fully on the end of the cable while soldering. Heat the lug with a torch, the flux will melt into the copper strands and remoxe oxidation. Apply the solder to the strands, right at the edge of the lug cup, it will begin to melt and wick into the strands, pulling into the lug cup. Keep applying solder until it stops wicking into the cup, and it begins wicking into the cable. You can see the cable color change as it does. After allowing it to cool enough, I grab the insulation and stretch it back over the wire strands until it touches the lug, then slide on a piece of heat shrink tubing with sealant inside and heat it thoroughly to shrink it and seal the connection. I use red and black heat shrink to denote the terminal polarity it connects to. I buy the heat shrink tubing from Fastenal.

[sowilliams]

I used solder pellets that have flux in them. I got them from Del City. Really easy to use. Just drop pellet into lug, heat until melted (I use map gas) and insert wire with just enough insulation removed. I keep a cup of water handy to cool off newly installed lug. Seems to work really well. I finish up with hd heat shrink of course. Anyone else tried these?

[yurtle]

I saw a video on those when I was preparing to do mine. I opted for a roll of solder, but those looked like they take the guesswork out of flux and amount of solder. Be sure and clean the inside of the lugs, to remove any oxides. I used plumbing emory cloth, but I've used fine brass wire brushes in the past.

[ClubCarDSIQ]

Originally Posted by sowilliams

I used solder pellets that have flux in them. I got them from Del City. Really easy to use. Just drop pellet into lug, heat until melted (I use map gas) and insert wire with just enough insulation removed. I keep a cup of water handy to cool off newly installed lug. Seems to work really well. I finish up with hd heat shrink of course. Anyone else tried these?

If I was soldering my battery cables, this is what I would use. I have made only one set of battery cables for a golf cart (4 gage for our old 84' 36V toaster cart), but I have made quite a few cables for motorhomes. These are 4-0 tinned marine wire with tinned power lugs. Our motorhome has 4 8D AGM batteries (650 lbs. worth) for a total 20 hour rate of 980AH feeding a 3000W pure sine wave inverter, so the requirement for 4-0 cable. Everything is sized for a continuous 400A draw, though it never goes that high for long. I also use adhesive lined heavy duty heat shrink on all of my high current draw DC connections. I crimp the lugs on using a crimper that creates a 360º crimp made by FTZ. I have cut the crimped lugs open to look at a cross section and the fine copper strands have, for all practical purposes become one with the lug. The tool is expensive at nearly $200, but West Marine stores often have one for in store use if you buy the lugs and cable from them. I get my cable and supplies from a marine supply place that I have frequented for a long time and get a slight break on the prices depending on how much I buy. The tinned marine cable is quite a bit more costly than welding cable, but the fact that it is very fine stranded and each individual strand is tinned throughout the length of the cable gives me peace of mind. The marine cable combined with the adhesive lined heat shrink, a 360º crimp and the heavy duty FTZ power lugs are, IMHO, as good as it gets, but I am sure that other options are just as good for all practical purposes.
Don

[ThreeCW]

I follow the Trojan Battery White Paper Recommendation that JohnnieB referred to in his Post #6 - that battery cable connections should be Crimped and Soldered.

I don't have a proper crimper, but follow the practice that my father used as a welder for 40 years by using a chisel to mechanically crimp the connection. This mechanically crimping in itself provide a good connection, but to get a "Great" connection, I follow this up by soldering it. I will flux the connection before crimping and by being crimped, the connection is easier to solder as the connector is fixed.

Here is the verbage from the Trojan White Paper that indicates the Crimped and Soldered connection as being superior:

"The infrared picture below shows a cable with a crimped connector under a high-rate discharge. Note that the crimped area is considerably hotter than the rest of the terminal post and the cabling. If allowed to continue the high temperature will be transferred to the terminal post through the connector and eventually a melting down of the terminal will occur.

It is therefore highly recommended that connectors not only be mechanically crimped but also soldered to the cable’s end.

A properly crimped and soldered connector will provide a low resistance connection and reduce the amount of heat buildup at the connecting junction.

The infrared picture below shows a cable with crimped and soldered connector under a high-rate discharge. Note that the high temperature area is no longer near the connecting junction but evenly distributed along the cable and battery terminal."

Refer to JohhnieB's Post #6 to view the pictures or the full Trojan document.

[Sergio]

These kind of threads always end up in arguments....

I have posted before that piece from Trojan is pure marketing material, meaning it has no scientific value.

You don't know the current being applied.
You don't know the amount of time exposed.
You don't know the type of wire.
You don't know the type of lug.
You don't know the type of crimper.
You don't know the condition of the parts used.
You don't know if both pictures used the same testing criteria.

... and yet conclusions are drawn.

The industry standard for large gauge terminations is crimping.

A proper crimped connection provides a "cold weld" that is gas tight, so unless You are using a cheap open end lug, exactly what can be soldered after crimping?

I like the FTZ heavy walled connectors and tinned marine wire myself.

As long as You can make a good soldered connection without compromising the insulation or provide a "fulcrum point" where the solder wicks into the cable itself, it should work better than a cheap "anvil" type crimper.

If you use the proper matched components, crimping will provide good terminations without much training or practice.

Even if you have the proper parts, soldering 2awg takes practice and skill to get a good termination.

Edit:

I want to make clear that I prefer soldered connections anytime possible, but given the large thermal mass of 2 awg cable and lugs involved, it is very difficult for a non-trained person to create a good termination without causing damage by overheating.