Cool thread! ...For my brief test I used a battery pack that takes 4 "AA" batteries and has a USB port connected to a hub to pass power to a little 1.8" HD I have in a tiny enclosure. I have no idea how long the setup would run for, but to me it's not an issue because I would never transport all the stuff anywhere to set up in the field. It's just too much of a kludge! ...