You will need a DC-DC charger which run $100-$250 if you want to charge from your TV.
I have a 50 amp hour lithium battery running some
lights, phone charger and occasionally hook up an inverter to charge a laptop. In cold weather I use a diesel heater which will run a couple 10 hour nights on a full charge.
I use a 100 watt
solar panel with a charge controller that will charge my battery in a couple hours of sun to full after a night running the heater, longer if partly cloudy, of course. It is a simpler setup that cost me $100 total.