I have a MultiPlus 3k inverter that replaced an old xantrex inverter when I upgraded to a lithium battery bank. The Xantrex was a 2 in 2 out and the victron is a 1 in 2 out. How am I supposed to hook up the other leg so my new inverter stops overheating and dropping power to 1/4 of my rv? Why did victron make this a 1 in 2 out? Is there a way to expand/add a component inside to facilitate my other line in? Is there an actual troubleshooting guide anywhere?