If you have a plain jane standard definition directv box it probably draws around 25-30W if I remember correctly. The TV can draw anywhere from 20W-100W or more all by itself depending on size and whether or not it's an LCD or tube. I wouldn't be surprised if the TV/sat box combo draws 12 amps or more while running. Lights can be fairly heavy draws too. LED's reduce that draw dramatically. Don't know how much TV you plan to watch, how many lights or how long the lights will be on, and with the cpap you're going to need a 2nd battery minimum AND a working charging system.