I bought a no-name 1500 watt (big enough to run the microwave) pure sine wave inverter off of E-Bay, but have used it very little. I increased my battery bank to 4 batteries. I wired the AC output of the inverter through the transfer switch that was already installed in my trailer with the generator prep option. I wired an external On-Off switch to the inverter, and mounted the switch at my inside control panel. I wired in a 200 amp fuse in the DC wiring to the inverter. I depend on the existing charger/converter to charge the batteries. I make sure to turn OFF the converter/charger AC circuit breaker when running the inverter, so I don't use the battery capacity to try to CHARGE the batteries at the same time.
At the time I installed the inverter system I was thinking that I would be boondocking some. My plans have changed and I stay in parks with shorepower now exclusively. I have only used the system a couple of times when I did Walmart park for a night, and when a storm took out the power for several hours at the RV park I was staying at.