Can just get a Inverter that can take 12VDC and make 120VAC. Thats what I use for powering computer stuff of a car battery during a power outage or when out camping with pop up camper and its a rainy day to game etc.
I have 3 inverters a 100 watt, 700 watt, and a 1000 watt. Depending on what the power needs are I will pair up an inverter with the setup. Also have a 4800 watt generator but the car batteries i have work out nice for silent power to not upset neighbors to the generator late night running. Had no power once for 3 days and ran the car batteries at night for silent power, and during day used generator to charge them back up and run fridge and oil furnace if needed etc.
Newer flat screen TV's dont draw much power. I have a 32" TV that draws 57 watts. If you want to know what your power consumption is if its not specified on the device the kill-a-watt device works awesome to know how much your draw is as well as you can go around and make a list of whatever you need to power and its power needs by turning it on and writing down its wattage when in use etc, then if you need to run multiple devices you know with very little error as to what your power consumption is, and if you want to go deeper you can calculate how long you can run before the 12VDC Lead Acid battery drains out if fully charged and healthy battery etc.
The last need for an inverter was when no power and I need an alarm clock to wake me, I left the alarm clock powered through inverter as I slept and it was safe and it woke me at 6am to surprise still no power but at least I wont be late for work by oversleeping until 9:30am
