1/0 gauge wire okay?

[Izeloz]

I am going to be adding a second battery to my '92 FJ80 as well as running auxiliary power to the back for an inverter, fridge, etc. I was wondering if 1/0 gauge welding cable would be acceptable for this application for all my main power runs. Thanks for any input.

[NLXTACY]

yes its fine BUT trying to get (2) 1/0 cables into the cab is going to be your nightmare. I literally in the middle of trying to decide where in the heck to pull the second cable. Its now holding up my trip.

[NLXTACY]

ok update, using some "lube" (don't ask), I was able to get the second 1/0 cable through the clutch pass thru

[Izeloz]

I already ran one 1/0 cable through the antenna grommet on the passenger side. Why are you running two? I am running one to a junction block just behind the second row and then from the junction block to wherever I need it in the cab.

[NLXTACY]

because if you are running an inverter it needs to have the negative run directly to the neg. on the battery, not just a body ground. I wound up running my whole aux. system this way.

Some teaser shots to my next FAQ:

[Bear80]

fyi, 1/0 cable is not recommend on power inverters due to the high resistance. 2 guage is highest recommended and at only 6ft lengths. Otherwise use 4 guage on longer lengths but keep the amp drawn under the inverters max output.

[NLXTACY]

1/0 was brought in for all Aux. Power to the junction studs. From there it goes out to smaller gauge.

[Izeloz]

I'm not understanding this, so please help me out. NLX, thanks for the tip about running the negative directly to the battery. You probably saved me from some serious issues. Bear, it is my understanding that the larger the wire, the lower the resistance. 1/0 is considerably larger than 4AWG. Please someone explain this to me. I thought the larger the wire the better.

[sdnative]

Originally Posted by Bear80

fyi, 1/0 cable is not recommend on power inverters due to the high resistance. 2 guage is highest recommended and at only 6ft lengths. Otherwise use 4 guage on longer lengths but keep the amp drawn under the inverters max output.

huh?

do you mean 2/0 and 4/0?

[NLXTACY]

My current set up. I followed the wiring guidelines AND the inverter manufacturer's suggested wiring/fusing.

http://www.btc-bci.com/~billben/maxwire.pdf

[Bear80]

The larger the wire the MORE resistance and the longer the length the MORE resistance. Most power inverters recommend against 1/0 gauge, I assume mainly becuase of possible issues that the resistance can have on how the inverter converts power. Maybe whatever that is pluged in could not operate properly, such as a lap top or the likes. I'd follow the instructions with the inverter, which probably recommends 4 gauge up to 6ft lengths and 2 gauges up to 10 ft lengths. That is what my 1100/2200 and 1500/3000 both recommended.

[Bear80]

BTW, amp wire or welding wire are the best choices due to their high strand count which helps lower resistance and stay flexable. I've noticed a double wire setup like this on high power inverters.

[sdnative]

Originally Posted by Bear80

The larger the wire the MORE resistance and the longer the length the MORE resistance

You got the second part right. The larger (diameter) the wire, the less resistance, all else equal.

Originally Posted by Bear80

I'd follow the instructions with the inverter

Probably the most sound advice yet. The manufacturers instruction should be the minimum wire size.

I cannot think of a single case where a larger wire would not be better from an electricity conduction standpoint than a smaller wire. Now physical size and cost may play a large part...

Originally Posted by Bear80

Most power inverters recommend against 1/0 gauge

I'd like to see supporting documentation. Most likely it's because they recommend 2/0 instead.