Hot Rods Welding Cable versus Battery Cable

Thanks everyone for your comments, much appreciated. I did not realise that battery cable was comprised of fewer and larger strands of copper and consequently was also stiffer than welding cable.
Based on all your comments, expertise and experience I will go ahead and use the welding cable (suitably supported) which I have and which will also save me a heap of dollars. Thanks again.

 

If we did have a cut or break in a welding cable, we would use copper tubing for the splices. We would use a dull chisel or the blade end of a chipping hammer to crimp the tubing to the cable. Some shrink tube insulation and half a roll of tape and we're back in business.

 

I use welding cable as jumper cables on my airplane with a Lycoming 0360 engine (360 cubic inches). I park the truck at the end of the wing where the airplane won't hit it if it jumps the chocks. The welding cable seems to work better than automotive battery cable when using it as a long jumper cable like this. I assume that there is less resistance per foot in the welding cable since the engine, in this example, cranks as fast as it does with a fully charged aircraft battery, even though the cables are super long.

 

You don’t live in So Cal. All of the guys I know have them along the inner frame over or thru cross members using insulated Adell type clamps if mounted in the trunk. We also use the frame for the ground with the same size cable between the engine block and frame. No salt.. no snow…. little rain…

 

My dad used welding cable for the battery mounted behind the drivers seat in his 36 Ford cabriolet. But he also ran the the cable through Seal-Tite conduit to protect it.

 

If you really want to protect the softer cable, go to an electrical supplier and buy industrial electrical bulk shrink tube in the appropriate size (much of it comes on rolls). That stuff is tough as hell, and once shrunk will remove almost all sagging of the cable. I'm pretty sure that's what those 'clampless' radiator hose kits use.

 

Seal-Tite and Liquid-Tite are 2 little used protective armor you can use on a car. The plastic/vinyl covering over galvanized steel or aluminum is tough stuff when used with correct end fittings. They work great as bulkheads also. If you have AC in your home it was used from the electrical disconnect/fuse box to the condenser/compressor pump outside for vibration.

 

My auto electrician recommended this cable for my 64 due to battery being in trunk. Automotive and NOT welding cable. It's double insulated and very flexible!

 

The double insulation your showing looks like a minimum of 4.16 kv. Thats 4160 volts and will test 3 times that. Personally that’s really over kill. It is also normally in conduit but can be in open air.

 

^^ Only going by recommendations, he's been in the industry and wired quite a few cars over time without issue. My car now starts when hot, something it didn't do previously when hot and fitted with standard gauge battery cable as there was too much voltage drop, cold starts weren't an issue. Added bonus is that it's flexibility allowed it to be easily routed and hidden under trim. I did need to upgrade battery isolator switch to a higher rating.

 

75% of the country has salt, snow and rain so I do my best to keep it out of those elements. No need for clamps if you run it the way I suggested to.

 

Not all battery cables are created alike, maybe just the ones readily available in the auto parts stores, which seem like the ones that are being compared most often to welding cables. The battery cable I bought from Ron Francis wiring is much finer strand than locally available, though not as fine as what mgtstumpy posted.
I didn't watch the video titled "energy doesn't flow in wires", but I suspect he's going to follow up with "energy flows ON wires", which is why finer strands of a given wire cable can carry more current. If that concept was brought up in any of the posts, I missed it. I learned that 30 years ago when reading multiple publications on house wiring. I always read.."be careful not to scratch the wires when stripping", but only one book explained why.......current traveling ON wires has to jump the gap created by the scratch, creating heat buildup, and a possible fire hazard. Seems unrelated to the discussion here, but it helped me understand a bit more.

 

I've had that cable for my trunk mounted battery in my roadster for 25 years. Same for the ground. And same electrician!

 

High count multi-strand cable like welding wire is better in terms of resistance per foot usually- I bought a length that has a dual insulation, a thin wrap of some slippery waxy paper inside, then a thick layer of rubberized outer. Designed to be walked on, dragged about and generally abused, I figured it should last under the car well enough with road debris etc. I routed it in the most protected route against the chassis that I could, mirroring the route the fuel line takes on the other side of the car. (I followed the brake pipe).

Haven't had any issues with it so far, it cranks over just as well as the original cable in the engine compartment did.

It's American-made, which is nice and conforms to SAE J1127, which is specifications for low voltage battery and welding cable. Made by Temco Industrial and it's 2/0 gauge. Bought it at my local Napa.

Guy at the store helpfully crimped the correct end onto it. Looks a little modern, yes, but I could always wrap it with something, I guess. Other end clamped down into a standard battery connector nice and tightly.
Stall current on the starter is about 300 Amps and that wire can take that abuse without burning up. A fuse at the battery end would protect the cable from a dead short, though.

Phil

 

Nope, that's not it. Electrical energy flows through electrical fields that are established when elecrons flow. The electrons themselves do not carry the energy, it is the electrical field established by the movement of electrons that carries energy. The old "energy flows ON wires" myth was never correct. There is a phenomenon known as "the skin effect" but that is a different matter that effects alternating current at very high frequencies. Watch the video.

 

I'm not sure why, but...could have something to do with things forming a ball where that started?

 

There's still a lot of misunderstanding/misinformation going on here...

First, the idea that 'finer stranded wire can carry more current' is only semi-true. Go back and read my first post in this thread. Any wire will have mechanical force generated in the wire when a current is impressed on it. In most cases it will be too small to see, but that doesn't mean it's not there. In practical terms, the only time this matters is where you have a conductor that may see extremely high transient current and the finer strands help reduce this mechanical force which could in some cases cause damage. The other end of this spectrum is high-current panelboards. These don't use wire, they use large buss-barring and there's very specific engineering specs defining how the buss is supported to prevent these now-larger mechanical forces from causing damage.

Second, the idea that finer stranded wire has a different resistance for a given length is false. ALL wire is sized by it's total circular mil area of the conductor(s) as expressed in AWG or whatever other 'standard' is used. Actual physical size can vary slightly depending on construction. The material used can vary the resistance (copper vs aluminum most commonly), and any current-carrying differences within given sizes/material has to do with the insulation temperature rating only. Where guys can get into trouble here is some of the ampacity charts floating around on the internet. A welding chart is really only applicable if you're welding. I particularly don't like the charts that define ampacity by wire length as they almost never tell you how much voltage drop that will produce and when they do it's usually too much. I stick with the NEC charts; while they're conservative, these are known values backed up by engineered data, not something cooked up by somebody with imperfect knowledge. FAA charts are even more conservative. My big beef with the aftermarket harness suppliers is they mimic the OEMs (who do the bare minimum to hold down costs) while adding a few more cost-cutting measures which negatively affect performance.

Every time this type of thread come up, I almost always bring up voltage drop. The thing to remember is voltage drop is the THE key to proper harness performance. Keep your total drop to any continuously operated device under 5% and all sorts of problems will disappear. You can tolerate a bit more for intermittently operated items. I'll also note that voltage drop has NOTHING to do with system voltage except as a percentage of drop. For a given amp load and wire, you'll have the same voltage drop whether it's 12V or 120V. But a 2% drop at 120 will be 20% at 12V.

That's not what that is about at all. While it's good practice to not nick the wire when stripping, it's only critical when using aluminum wire, not a big deal on copper. Typical practice for stripping large copper conductors is to 'ring' the insulation with your knife for the length you need, then cut it length-wise, then peel the insulation off. If doing aluminum, do the length-wise cut first, then peel the insulation while ringing it being careful not to contact the wire. With smaller aluminum where it may not be possible to do this, the method is to act like you're sharpening a pencil. The trick is you don't want any sharp/deep nicks at 90 degrees to the soft aluminum wire strands. Because of the mechanical forces at work on the wire, the flex at the nick can cause the strands to break, which can then cause arcing, burning the connection in half.

When stripping fine-strand wire, the best way to do it is first cut the wire a few inches long at each connection point. Then ring cut the insulation, being careful not to go all the way through. Once you've done that, bend the wire at the cut and just touch the blade enough to part the insulation without contacting the wire. Next, trim the wire to the length needed for the connection, then pull off the insulation. This keeps the end from 'separating', making it much easier to insert the wire into the connector.

 

It looks like we have pretty well established that welding cable can be effectively used as battery cable...........BUT, no one has addressed if we can use battery cable as welding cable...............

 

^^^^^^^^
Well I don't see why not. I used an adjustable wrench one day wedged between the battery ground post and the radiator support. In hindsight I wonder why it didn't fall off into the engine fan.

 

Who is "they"?
From numerous threads over the years we learn that regulations about modifying cars are much stricter in Australia than in the US (or Canada).
Perhaps it is just that welding wire will not pass inspection because it doesn't have automotive approval markings. And the inspector may agree that it's perfectly good, but alas, it doesn't have the stamp of approval.

 

Another source for cable is an industrial battery (forklift) supplier. They will sell you the length you need and also have the terminals and shrink. Red and black also if that is what you are looking for. D

 

from my experience the clamps on jumper cables don't hold the rod as well but aren't to bad for ground clamps

 

If you use welding cable, you can also add a welding cable splice in the line for a quick disconnect feature.

 

https://www.mcmaster.com/battery-terminals/solder-loaded-battery-terminal-clamps/

^^^^ This shit is what you need. Fuck crimpers. They suck. Try these out, you will never go back. They make the same ends for bolt on terminals too for starters and grounding to engine block/frame. Clamp the terminal open side up in the vise. Apply torch to melt solder/flux combo. Insert stripped wire. Done. Wear gloves and safety glasses. Don't forget to put the heat shrink tubing on the wire before soldering though. D'oh!!!
Andy