Gauge Wire Size For Battery Isolator?

(tjhooker) · (tjhooker) **Join Date: Apr 2002** 06-10-2004, 2:48 PM

What gauge wire size should I use to connect the 2nd battery to my new battery isolator? Also, where should I connect the ground wire for the new battery? Any suggestions are greatly appreciated.

(rodmcinnis) · (rodmcinnis) **Join Date: Sep 2002** 06-11-2004, 12:52 PM

What size alternator do you have?

How long will the wires be?

The bigger the better, but I would recommend at least 8 awg. The isolator only carries the current from the alternator so the wiring doesn't have to support more than that.

The ground wire for the second battery would be best attached to the block of the engine using a large battery cable.

Rod McInnis

(cmawsr) · (cmawsr) **Join Date: Nov 2002** 06-11-2004, 8:10 PM

I just added a second battery and isolater, I used #2 all the way around

(tjhooker) · (tjhooker) **Join Date: Apr 2002** 06-12-2004, 12:20 AM

I am not sure on the alternator size but probably a 50 or 60 amp alternator. Does that help?

(switch) · (switch) **Join Date: Oct 2003** 06-13-2004, 10:27 AM

Mike, if it helps I used 4 gage to my extra battery. And than 2/0 to the juction box.