Originally Posted by GJorey
Anyone know what gauge the wire from the house battery to the inverter is? Replacing battery with a pair of Battle borns and want to reuse the wires that go under to the battery to hook up the new batteries. Need AGM gauge size to order new connectors.
Welcome to the forum GJorey!
All cables I've seen have a gauge embossed on the cover. As Avanti said, you may have to have just the right light an angle to read it, but it should be there on your existing wires.
Otherwise, to determine the gauge you want to replace them with (if you even need to) will be calculated by length of wires and power (amps) they need to handle.
When I did my Lithium battery & 3000W inverter upgrade, I initially used 4 ga. wires. The reason? It was what was originally used in my van, my runs were about 1/4th the original length, and it was all I could source locally before we took a trip. Of course, with the intention of running the microwave at about twice the old inverter capacity, my intent was always to upgrade the wire gauge.
However, for the few months with the 4 ga. wires (max 4' length) the wires never got warm. The only time I felt the inverter positive wire getting mildly warm was when I was load testing by running the batteries down using a 1600w heat gun for over 15 minutes. They never got warm just using the 1200w microwave (rated as a 700w model) for 3-5 minute periods.
The above being said, I went overboard and rewired with very thick 4/0 gauge copper welding wire cables which were truly overkill. When I ordered my cables from ebay acdcwireandsupply https://www.ebay.com/itm/4-0-AWG-GAU...72.m2749.l2649
(who are great by the way) I got the largest gauge wire available because it was only incrementally more expensive than the next smaller gauge. However, it is heavy gauge and harder to work with. If I did it again, I'd use 2/0 or 0/0 wire and not ever worry about it.