battery-powered nano-itx

[Factorxfiles]

Just wondering how hard it would be to rig up a nano-itx to run off battery. I'm talking about like with a pico-psu inside, and a battery pack or something hooking into that. Those things are dc-dc so it seems feasable. Is there an adapter or something for this?

Or alternatively, is there a way to hook up a laptop battery internally?