Source: http://gizmodo.com/5880609/this-15000-lumens-led-light-cannon-will-turn-night-to-day
You can forget about hanging it from your belt, because this miniature sun—masquerading as a flashlight—is heavy enough to need two hands to operate. And with 15,000 lumens, the XM18 is bright enough to illuminate a small planet.
As you can see, it's actually composed of 18 smaller LED flashlight components, all wrapped in a custom housing powered by 32 lithium batteries and cooled with its own fan. LEDs are definitely more efficient than incandescents, but 15,000 lumens worth still produces a lot of excess heat.
What's even crazier is that the $2,500 photon cannon (built only as a custom order) is shaped like a hexagon so multiple units can be easily mounted together. Because apparently the company is worried that 15,000 lumens might not be enough for their most discerning customers who need to blind entire herds of deer at once. [4Sevens via GoingGear]