My inverter for my RV has a watt display on it to tell you what you're drawing while in use. I was going to get a 2000W inverter, but I went for the 3000W because it was only $70 more. I'm glad I did because with just a few things on, you get to 2000W pretty quickly. If you're wanting to get something for traveling and dual purpose, home backup, I'd get the most watts you can put in the truck by yourself without dreading having to do it.