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.
1/0 gauge wire okay? (1 Viewer)
- Thread starter Izeloz
- Start date
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NLXTACY
Wits' End
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
Wits' End
ok update, using some "lube" (don't ask), I was able to get the second 1/0 cable through the clutch pass thru
- Thread starter
- #4
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
Wits' End
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:
Some teaser shots to my next FAQ:
NLXTACY
Wits' End
1/0 was brought in for all Aux. Power to the junction studs. From there it goes out to smaller gauge.
- Thread starter
- #8
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.
NLXTACY
Wits' End
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
http://www.btc-bci.com/~billben/maxwire.pdf
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.
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You got the second part right. The larger (diameter) the wire, the less resistance, all else equal.
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...
I'd like to see supporting documentation. Most likely it's because they recommend 2/0 instead.
Sorry to bring this back up this many months late. The above statement is very misleading. It speaks of both "larger wire" and "longer wire" saying that they both equate to MORE resistance. If by larger wire you mean wire with a larger diameter - than you are incorrect. A larger diameter wire will have less resistance per foot than a smaller diameter wire. ...otherwise there would be no point in making larger diameter wire at all.
To answer the OPs question, or anyone who finds this using search, the answer can only be retrieved from the specs of the inverter. Is it a 20W inverter, a 2000W inverter or somewhere in between? The manufacturer will have the required cabling specified for the inverter in the installation manual. It is possible to stretch out their recommendation by going to a larger gauge but you could be wasting a lot of money by blindly going to a 1/0 cable. This site shows the resistance values for different diameters of wire and has a calculator for voltage drop at the load with different lengths and diameters (if it disappears look up another wire size calculator): American Wire Gauge table and AWG Electrical Current Load Limits (I have no affiliation, I am not even a customer) If the manufacturers recommendation is no more than 10 feet of 1/0 cable at 105 amps - you can see that it will result in a .212 volt drop at the load. If you need to increase that length to 16ft - you will find that the diameter must be increased to 3/0 cable to handle the increase in distance without affecting the voltage drop at the load.
