http://kaidomain.com/bike-lights-and-bike-accessories/Bike-Lights/KDLITKER-Bike%20Lights/KDLITKER-BL70s-Cree-XHP70_2-3000-Lumens-4-Mode-LED-Bike-Light

Check out this XHP70.2 thing from Kaidomain 36 USD BL70S . I got one of those and its not bad, I believe its a genuine XHP70.2 I also measured the power, about 20W from the battery. and its pushing 2.4 Amps thrugh the LED at max. The thermal design is allright actually, with a solid wall behind a copper mpcb, no thermal junctions.

Modding to get the amps up is possible by adding a few 0.25 Ohm sense resistors and going for a 3S battery pack. Doing that i can push this thing to 50W , and about 5 A through the Led. :slight_smile: Only for full speed downhill off course, it gets pretty hot at that power. but damn its bright, dont have equipment for measuring lux, but its more than bright enough for downhill skiing/biking.