Battery Cables

[TomC]

I'm getting close to having to wire up my inverter and house batteries. What about making cables out of welding cable? Good Luck, TomC
https://www.wireandcableyourway.com/Welding-Cable/

[richard5933]

That's what I use. Much more flexible and easier to work with. I splurged on a hydraulic crimper, which makes it much easier to install the lugs.

[bobofthenorth]

I can't think of one reason NOT to do it that way.  I won't tell you exactly how I'd do it because that would start a massive thread war but I'd definitely make my own and I'd use welding cable to  do it.

[DoubleEagle]

One of the drawbacks to welding cable is that the strands of copper are very thin (which makes the wire very supple) and are corroded more easily if unprotected. There was welding cable on my 1982 that was so corroded I could easily yank the wire off the terminal connector because the insulation had shrunk back over the years, leaving an exposed gap. Welding cable is not SAE approved for automotive use, and the insulation is not oil resistant. A better cable is SAE SGX or SGT-M which have higher heat ratings, are oil resistant, and are not as expensive as the tinned marine cables. Tinned marine is the ultimate in cost, but SGT-M is rated for marine use, and has self-extinguishing insulation. If the terminals are professionally done and the cable is totally protected, there is less justification for tinning. If the welding cable is constantly exposed to oil (now how could that happen on a two-cycle?), the insulation will swell and get weaker. It might work for years, but then cause problems down the road. 

[richard5933]

Regarding the insulation on the terminals/lugs...

There are two types of shrink tubing. One is just a plain shrink tube, and the other has heat-activated adhesive inside. My experience is that the shrink tubing with adhesive makes a very good seal against the lug and should help eliminate corrosion. Just my experience, and I have no idea if this is SAE or not. I've only been doing this on my battery bank, which is in a clean location, so oil/grease contamination are not really an issue.

I just checked the product description on the cable I bought (from Crimp Supply), and here is what it said:

     Operating temperatures is -58°F to +221°F (-50°C to +105°C). Rated to 600 volts. RoHS Compliant and meets SAE J1127.

From my layman reading, this would indicate that this particular welding cable would hold up with exposure to oil/grease. I'll have to do more research to state anything definitively though.

[DoubleEagle]

Nope, those standards would not address oil resistance. J1127 refers to proper copper content per gauge, and RoHS concerns absence of restricted ingredients such as lead, mercury, cadmium, etc. The principle types of battery cables are stranded bare copper with PVC, Rubber, TPR or Cross-Link Insulation. The lowest maximum temperature rating is for SGT at 85 degrees C, then SGR at 90, and SGX at 125 degrees C. Battery cable is rated to 60V; welding cable at 600V. Welding cable is not SAE rated. Welding cable is very supple because of the fine strands and the soft insulation, which can crack in time and let corrosion agents in.

[TomC]

Class W looks more like it.

[kyle4501]

I looked at the cost of tinned marine battery cable VS the non-tinned battery cable. The difference was such a small percentage of the total cost, it was a no brainer to use the marine cable.
I also upgraded to 4/0. (After loosing 2 starters due to hidden corrosion, I wanted as good as I could get.)

The adhesive heat shrink is what stunned me at the cost, man, that stuff was expensive!

While you are at it, make sure you get the good tinned lug ends. The cheaper ones can allow acid & moisture to enter thru the bolt end.

I also used a silicone dielectric grease inside the lugs & worked it inside the wire ends before crimping.

[TomC]

Don't need all that anti-corrosive stuff when using AGM batteries.

[gumpy]

I made mine using 4/0 Welding Cable with the adhesive shrink tubing. Have worked great for about 15 years now.

Check out www.waytekwire.com.  Been awhile since I've looked at their site, but they had a good selection, decent prices, and good service way back when.

[eagle19952]

A whole herd of heavy highway construction maintenance welders would have crapped out more than a few miles of welding lead if it wasn't oil resistant.

Some ship welders too

And pipeline too.

[Jim Eh.]

If your cable is too "supple" when used on a mobile application will it not "swing like a rope"? I would think that would tend to wear on anchor points and bulkhead isolators.

I don't think there is any shrink tube that will bond completely to wire insulation unless it is similar material. Plastic doesn't seem to bond to rubber very well. Plus it has to be darn near surgically clean before shrinking. Any mold release (in the case of non natural rubber jacket) left on the outer surface and I don't think it will bond or seal.

[kyle4501]

Don't need all that anti-corrosive stuff when using AGM batteries.

Battery acid ain't the only thing that contributes to corrosion. The corroded connection that caused all of my problems was no where near the batteries. . . . . So much for that theory.

Welding cable insulation can be neoprene, EPDM, or PVC ( Standard, Semi-rigid, or irradiated ), so not all welding cable is the same. If you don't know what the insulation material is, you can not possibly know how it will perform.

Sometimes, ignorance is not bliss . . . . 

Cables can be adequately secured to prevent unwanted movement, the more supple, the more supports.

As for the adhesive heat shrink, I bought Ancor marine battery cable & the Ancor adhesive heat shrink. I made some test connections & cut them apart to verify the quality of the crimp & heat shrink. The heat shrink bonded so well with the cable insulation that the joint could not be seperated. With the correct lug ends, the wire was fused together in the crimped lug.

[Iceni John]

Everybody here is talking about the cable and heatshrink (obviously very important factors), but what about the actual crimping process?   I've seen plenty of cables, including high-current starter cables, whose lugs are attached by those hammer crimpers, assuming such a tool deserves to be called a crimper!   To prevent moisture wicking between the strands, and to assure the best possible electrical contact between cable and lug, the lug ideally should be squeezed on all its sides so it compresses onto the cable so tightly that it and the cable have effectively cold-welded themselves together into one solid indivisible fused mass of copper.   No hammer crimper will do this  -  all they do is dent the lug down into the strands of wire, leaving individual strands still separate from their neighbours.   No bueno.   I purchased a FTZ 94284 circumferential crimper from K.L.Jack after reading about it on a boating website http://www.pbase.com/mainecruising/battery_cables   It easily squeezes the lug on four sides to produce a completely solid joint  -  I test-cut one such joint apart to look at it, and the individual copper strands and lug had fused so tightly together that I couldn't pick them apart or separate it at all.   Very impressive.   The crimper's dies can be set to any lug size and thickness;  if I'm not sure what will work best I start with a looser crimp, then change dies to make it progressively tighter.   If you're making more than a few cables (I've made literally dozens so far, and I'm not finished yet!) then it's well worth buying a good crimper.

Also, don't cheap out on the cable cutter.   If the cut end is ragged and uneven it makes it difficult to get all the strands inside a tight-fitting lug.   I use a long-handled Temco cutter that's rated up to 250-size cable, much bigger than 4/0, and it cuts 4/0 welding cable like a hot knife through butter, leaving a perfectly flat smooth end.

Making cables is fun, and you can make them exactly how you want, with the lugs' orientation or even the cable's intended bend all part of the process.   Watching how some "professional" marine and vehicle techs make their cables made me quickly realize I could make mine better myself!

John          

[kyle4501]

John,
While you make an excellent point (that I agree with), I don't think that someone who is worried about the cost difference between welding cable & tinned marine boat cable is going to be able to understand the value of the proper crimper and wire cutter. 

At least they have been exposed to a more robust way.