14 volt tv and the inverter squealing.

So this morning I unplugged the shore power then checked the batteries with a load bank then waited 2 hours and checked them again.the needle went to the line between ok and weak it wasn’t in either box, going to let it sit overnight and check it in the morning. I’m not against changing batteries however these are iffy. I am ordering a new 4 stage converter for sure. The tv, I’ll get to that eventually.