Tv operation on battery power?

The inverter is a box that converts DC battery power to AC power which is what your Television needs. Depending on what you're trying to power with it, they can go through a lot of battery power in a hurry. As a result, you'll want to study up on how to determine your overall power needs. From there you'll be able to work out what sort of battery power you're going to require, how big of an inverter if that is what you determine you need, and what all you're going to try to run off the inverter. If you intend to use battery power to power an inverter for more than a night, you'll start running into the need for a fairly large bank of batteries, or maybe a generator or solar battery charging system.

I'd start slow initially until you decide what sort of camping you prefer, how often and how long you need to go on battery power etc before you try to get an inverter installed.

By the way, welcome to the forum, and the RV madness.