I’m running 8 gauge for my home run and it looks like it might take 4, but I’ll confirm when I do the install (all my PV gear is at the cabin) - manual states 8. The battery studs look pretty solid, there is heavy solder around them, but they're mounted to the board, which gives me pause, although I won’t be moving the cables post install so not overly concerned. AC in calles for 10awg, I’m running 8, so will know on that as well post install. The Renogy AIO I had the battery studs were more solid, but I didn’t like the unit for a few reasons: tight cable openings, wasn’t drawing anywhere near the PV output from my panels it should have been in full sun despite changing all of the settings, really poor app integration, Renogy customer service was really, really bad. Onward and upward.