I am trying to think of a better way to demo lights. I don,t want to buy a demo kit. The vista ones break alot, or are either out on loan. Has anyone tried to rig up a 9 volt battery to a light? It would be portable, faster, and easier. I tried it the other day and it would work with led but not with halogen. Then with led, the 9 volt was dim, but 18v was very bright. Any ideas out there?