I get asked all the time about what type of wire I use to build the cables

I get asked all the time about what type of wire I use to build the cables. Some guys want marine grade wire or they heard that welding cable is the hot set up.
Below is a description of what we use and my opinions about if you should use be using marine grade wire on your Dodge Dart.
Marine Grade:
Marine grade wire is usually "tinned" (plated) to help reduce corrosion. It also has an insulation which is rated for "wet" (think submersed) applications. It's usually rated for a higher temperature (I sometimes recommend it for automotive applications because of that). Sometimes it has a higher strand count and is more flexible for that reason. Because it is flexible it might not not stay were you put it. It is also much more expensive (think twice as much).

There was a time (when I was grumpier) when ask about marine cable for a car that I would answer "Are you going to be taking your Taurus out to sea??". I thought it was a waste of money. I still do in most cases. Then a friend pointed out that perhaps marine cable would help if one lived somewhere near the ocean and a salt atmosphere, or maybe salt on the roads. I guess that might be true. I live in the desert so I don't have any personal experience with such things. However, I can tell you that once we install the lugs, terminals and the heat shrink is applied, no wire is exposed. So, I honestly doubt it actually makes much difference.

Because of the high cost I only stock small quantities of marine cable but if I don't have it, I can order it. Expect it to take a couple weeks longer.

I absolutely believe that it should be used on boats. After all that's what it's made for. In fact I won't build you a boat cable out of automotive wire.

Pro's: High temp, Flexibility, Corrosion resistance, Wet applications.
Con's: Very expensive, Some times hard to get, Special order,

Welding cable:
Welding cable is built to be flexible so the welder does not have to work hard to drag the wires around. It usually has a high temp rating and a soft flexible insulation. I'm not sure about the abrasion resistance or other attributes of the cable. I have seen it swell up when exposed to oil... so do NOT use it in an application where it will get all oily. Some guys claim that because it has many fine strands it carries more current due to "skin" effect. Those guys have forgotten that "skin effect" is a high frequency phenomenon (think microwave communications) and does not exist at DC.

I have some battery cables on my cars that I built with welding cable. It works fine but it is more expensive. (I used it because I had some let over pieces).

Like the marine wire, I stock small quantities of welding cable and if I don't have it I can order it.

Pro's: High temp, Very flexible.
Con's: Expensive. Soft insulation. Not oil resistant.

Battery Cable:
We generally use SAE (society of Automotive Engineers) SGT battery cable. SGT designates the type of wire. For example THHN is probably what you have wiring your house. SGT is self extinguishing PVC insulation rated at 50 Volts. It's typically rated for 85 degrees C. This is the lowest cost wire of the 3 wire types discussed here and it does the job just fine. The strands are larger than the other two, making the wire stiffer so it stays where you put it but still flexible enough to bend around tight corners.

Sometimes we use SGX wire. SGX has a higher temp rating but the insulation is thicker and stiffer and it costs more. If you need the higher temp rating, it might be a good solution.

Pros: Lowest cost, SAE rating. Less worries about wires moving around.
Cons: Lowest temp rating.

High Strand Count:
Some folks are looking for high strand count battery cable. Perhaps they have read it's somehow "better". I've had some folks tell me that it carries more power due to "skin effect". That is just plain false. Skin effect is a high frequency phenomenon (think microwave) and is nonexistent at 12V DC. The high strand count is more flexible but in an automotive application the cables get installed once then hopefully they never move again. So flexibility isn't really an issue. The high strand count is more expensive (think 2x). In my humble opinion that's about all it does "better" than the lower strand count in under hood application... cost more.

My Opinion:
Personally, for automotive cables, I like the SGT battery cable. It's works great at the lowest price. Beside it has SAE rating. Why pay for marine grade wire if the automotive works just as good?

For boats you got to have marine. Isn't that a Coast Guard rule?

Welding cable makes great booster cables or portable inverter cabling. Nice and flexible for when you roll them up and put the back in the trunk.

email me if you have any questions or comment.