Some of the televisions, normally the smaller sized ones, will come with multiple power supplies that will allow you to run off 120VAC, 12VDC (vehicle accessory plug), and batteries.
I have a 7" Haier HD television, that does the multiple power sources. The biggest AC/DC/battery powerd television I've seen is 13.3 inches, also has all the bells & whistles, including DVD player on Amazon.
2016 Forest River Heritage Glen 276RLIS
2012 Chevrolet Silverado LT 3500HD Duramax