12v Battery Wires Sizing

[HB of CJ]

Yeah...about the same answers/observations.  Welding cable in 4/0 is quite flexible.  Be sure to use heavy crimped connections with shrink wrap plastic.  Stay sway from any soddering.  If memory serves, most cable sizing tables assume a very high voltage drop, usually around 2.5% to 5.0%.  The invertor will be happier with cables sized for about a one-half % voltage drop.  Much, much less.  Could the invertor be moved closer to the batteries?