Help me buy an inverter

I have an inverter setup for powering the outside fridge and a kuerig mini. I used a xantrex prowatt transfer switchhttp://www.donrowe.com/Xantrex-808-0915-PROwatt-SW-Transfer-Switch-p/808-0915.htm wired into the trailer electric panel. It switches power automatically from shore power to the inverter. On our camper the kitchen, bath, exterior outlets, and outside kitchen are all on the same circuit(gfci). So all of those outlets are hot when on inverter or shore power using the xantrex transfer switch. I also installed 2 agm batteries, relocated to directly under the electric panel next to the frame rail. The inverter I had been using was a refurbished motomaster (xantrex) eliminator 1750w msw. That inverter failed after one season. i have not replaced it yet. Other than that failure, the setup worked well for the fridge, but the keurig would only work with fully charged batteries, and the fridge off.