I was wondering if using 0 gauge stereo amplifer cable would be just as good as using an official "automotive battery cable." I can get the stereo wire for cheaper. I plan on replacing the pos. battery cable that connects the two batteries in parallel, as well as connecting a third battery in my tool box. The only thing with the stereo wire is that the strands are much finer than regular battery cables. Not sure if this would be an issue like causing more corrosion.

 

If it were me, I would go to your local welding shop and get some thick strand 0-2 gauge. The fine wire may melt under the amperage load.

 

Hmm, that's a good point.

 

But let me see. The 0 gauge stereo wire is rated for up to a 3000 watt system. P=IV, 3000 watts/17 volts = 176 amps and 3000 watts/11 volts = 273 amps. So it should be able to handle somewhere between 176 - 273 amps of continuous current. How much do the grid heaters and starter motor suck on a cold start?

 

0 gauge will work fine perhaps better. More strands = more current flow, Its more expensive to make then your underground or some welding cables, but its also more readily available which makes it cheaper, current travels on the outside of the wire more srtands = more surface area = better connectivity.

 

While the stereo cable may flow better, shielding might be something to think about. You definately don't want any current bleeding off of the cable into other smaller wires...

 

Also take length into consiederation 4 ft of 1/0 will handle well over 300 amps continuous which is way more than the grid heater the starter and the heater will draw combined.

 

What shielding do the factory wires have? Car audio products are made with that taken into consideration for obvious reasons of sound quality.

 

I think it would work just fine.
When I was in Mexico saw that ten strands of baling wire pushed though a hose worked for them.

 

Ok sounds good. I think the stereo wire was built with a little better quality because they don't want it to hurt sound quality, as mentioned above. The wire I was looking at is actually equivalent in inner diamter to a 2/0 wire so it should be plenty thick.

 

By the way, if anyone is interested in wire, here's where I plan on getting it:

http://cgi.ebay.com/ws/eBayISAPI.dll...0149&rd=1&rd=1

Cheapest I found on ebay and they happen to be in my town. I've bought from them before, they're generous people.

 

The most current intensive device in the truck is the grid heaters. They pull a combined 180 amps during preheat. A 0 gauge wire should handle this with ease, but be aware that even wire this thick has some resistance. 0 gauge has 0.096 ohms per foot. So a 5 foot length has approx. 0.5 ohms if resistance. So basically, the wire will "rob" a bit of the second battery's current. First I'd make sure the cable you're replacing is 0 gauge or thinner. Second, I think I'd be very concerned about the ability of the insulation to handle extreme underhood conditions as well as its resistance to various chemicals, oils, and fuel. High strand count makes the cable limp and easy to handle, but battery acid and salts can intrude under the insulation and corrode the fine strands much easier than cable with lower strand counts. When the fine strands corrode and break, the resistance goes up in that location, and you form a little hot spot which could possibly melt the insulation and suddenly you have a little impromptu welding party going on under your hood. Use it with caution!

 

Comatoze said it very well.
Fine strand wire is better at conducting because of the added surface area but there is more to the story. The extra flexibility and questionable insulation may be a problem. If you get flexing at the terminal and some corrosive atmosphere the fine strands may begin to fail and then you'll get high resistance and extreme heat soon. Then the insulation will fail and........
Fine strand welding cable has a very good jacket. Tinned wire is very good at corrosion resistance and is used around boats and salt water. Battery cables are not shielded. And you should not solder the cable into the terminal socket. It must be staked because if you ever do get it hot enough to melt the solder (I've been there) the connection suddenly fails completely and can even fall apart.

Wetspirit.

 

In the past I have used 2/0 welding cable and made my own terminals. Bare just over an inch of the cable and slide about 2.5 inches of 1/2" copper water pipe over it until the bare wire sticks out the end.. Flatten the end just long enough to fit comfortably under the nut at the battery clamp. Then drill the right size hole you need thru the flat part. (thru the pipe AND the wire) Once it is clamped up it will not cause a bad connection. If you are in an area that uses salt on the roads I would seal both ends of the copper pipe to prevent the ingress of salty water.
OK, this does not look quiet as neat as a factory terminal, but it works and is dirt cheap. Round the end if you want appearance.

 

Just last weekend i replaced both the neg. and pos. battery cables in my '92 CTD. I used some real good 2/0 welding cable i got from work, which goes for about $3.17/ft. It has a good heavy outer covering made for use in outdoor environments. I crimped on 2/0 heavy duty ring terminals (3/8" hole), no solder. then i heat-shrink tubed the connections between the cable ends and the terminals. I also installed some wire loom covering over the cales for extra protection. They actually came out really nicely

I was AMAZED at how much easier the truck cranked over, and how bright all the lights were. Since i owned the truck, the dash guages worked sporadically at best, and now they all work great. I was definitly having some ground issues with the truck, but i think they are solved now. My positive cable to the stArter was full of that green dusty corrosion garbage, that i had not noticed until i cut the battery terminal off . I also replaced my battery with a threaded post type group 31 out of a peterbilt.

Just some food for thought, considering that i had just done this. good luck