0 gauge? Wussy. I used 4/0 (about 1/2" thick conductor) for a 18' run from the front of my truck to the back. Bought 30' of it for $30 shipped a few years ago. Yes, $30 total, or a buck a foot. It was marine cable, designed for corrosive environments, and was double sheathed. The outside sheath was for high abrasion resistance and was about 1/4" thick. It had a crazy high strand count (2+ thousand IIRC) for serious flexibility. I still have about 10' of it in my garage, along with a bunch of 2/0 and 4 gauge wire that was made the same.
I actually had the relay short out internally in my truck a few years ago. The full current of 3 red top optima batteries ran though the cable for about 2 minutes while I was disconnecting the cabling. The amperage was so high that the relay itself melted, the firewall partially melted, two 2 gauge ground wires melted, and the stainless steel brake lines between the firewall and frame (the last grounding path that didn't melt) were glowing white hot and set some of the regular wiring on fire even without direct contact. When I was disconnecting the 4/0 cable I could feel the hum of the electricity passing though it, but it wasn't hot.
The next morning when I checked the batteries they were at just over 12 volts (~0% remaining charge) which means in that 2 minute span I used up the 465 minute reserve capacity of the batteries. To pull down that much wattage in 2 minutes means the full amperage was somewhere north of 5000 amps. (465 min*25 amps = 11625 amp/minutes, or 5812 amps for 2 minutes) That's nearly 70,000 watts. The radio transmitter on top of the sears tower is only 50,000 watts. Wee!
Facebook
Twitter