+1 make sure converter is off
Think about buying a DC AMP Clamp multimeter. These are INVALUABLE with solar and finding out true amperage used/gained.
What gauge of wires go from the batteries to the inverter? YOU MUST HAVE THICK WIRES HERE. Your voltage loss will be amazingly high and the wires will get very hot under use.
You should have AT LEAST two 4ga or one 2ga wire. This is also a topic for debate, I'm giving a generic 'no less than.'
If the wires look like the wires from the Solar panels you probably have a problem.
Also, Is there a fuse between the battery and the inverter for no more than the max amps that the wires are rated for? (If the wires are rated for 150a, NEVER put a fuse higher than that on them, else the wire becomes the fuse)
Also, your inverter is overpowered for your batteries, and the panels will likely NOT keep you charged up. (~10 amps/hour full sun of charge rate) Consider two more 6v's if you want the power the 2000 can give out. Also two more solar panels.