I can not see dragging around a 15" TV all the time.
About three years ago I bought a Field Monitor. They are more or less
sold as camera monitors and a quick search and I came up with
this one.
[Link: lcdracks.com]

Not the one I have, but you get the idea.
Mine came with two batteries and a power supply.
Has composite, component and HDMI inputs.
Thing is awesome and use it way more than I thought.