Just hook up a cheap lipo pack from any mobile phone and you are good for many hundred hours.
Great idea! Cheap, plentiful, and even a used pack will give you more then 10 hours. Plenty of room in the case for sure. Maybe Dave will prove solder points for it in the future. (he for sure won't be shipping lipo batteries!)
The down side of a pcb as a front panel of a box, is that it's so light weight, it doesn't stay in place...and ends up all over the workbench with a tiny bit of test lead moment. On some test rigs, I've taken to mounting them to a chunk of 3/4" MFD for some mass, and some 3m rubber feet. Keeps things nice and stable. So a battery, (and maybe some other weight) would be welcome!