Shooting with off camera flash is great right? Of course it is. And while hotshoe flash units are OK, wouldn't it be great to shoot with the power of a studio light? Of course it would. They do make portable batteries to run studio lights while 'out in the field'...but one problem is that they are heavy. The Vagabond II from Paul C. Buff, for example, is 18 lbs....portable but not something you would want to carry around too long. So a photographer I know built this little kit. It can give you a couple hundred flash pops with an average studio strobe and weighs only 6 or 7 lbs. Attached to the bottom of a light stand it makes a great 'sand bag' and you can move it around just by grabbing the stand. I borrowed this for a shoot this week and it worked great. The strobe recycled almost immediately, just as if it were plugged into a wall socket. I have bought the parts and the charger to make one myself...more details to follow when I put it together.