Inverter problems-a bit long

I have an Arctic Fox 25Y trailer that I bought a few years ago used. It is in good shape, but I seem to have a problem with the Xantrex 2000 W Freedom XP inverter. I know nothing about inverters, and have used it only to run the TV. My last fifth wheel I put a hard wired 500 W inverter to use for TV. We have a Zamp Solar Controller/battery charger, 360 W of panels that work good as long as you have any sun, a High Pointe microwave 900 W output-1350W input, a Champion 2000 W inverter generator, 2-6 volt Interstate Batteries. I figured I would try the inverter with a higher task than running the TV. We had a couple of TV dinners, the batteries were up good, and so I wanted to see what my set-up could do. It ran about 1 1/2 minutes and shut off. Taking a lot of power. So I hooked up the generator and it did just slightly better before shutting off. Here at home I tried it hooking up to 110 plug and it worked fine. Now according to my voltage meter on the batteries it is running at 15.5 volts. Normally it will be at 14.8 until it reaches full charge than down to 13.6. Can anyone tell me what is going on, and if I have a problem, where? Thanks for the time.

Mike