Bicycle 3W Led Retro Headlight

Step 2:

Place the Led and the heatsink together using the thermal compound, then put the lens on the led.
As a holder you may use a plastic hairspray cup and cut the small hole in it. Put the Led with the heatsink and the lens into the cup and screw 3 small screws (sorry for my English, I'm Ukranian guy :) )

Using glue - take the Led driver stick to the heatsink) Also stick the heatsink to the plastic cup

test it all together witn the right polarity with led driver
It is quite simple scheme - you should find polarity indicators on the Led and the Led driver

The overall durability is about 100 000 hours - almost forever! (thanks to the 700mAh Led Driver, which gives stabilized voltage in 3.8V. The batteries gives 7.6-8.2V.)
Total cost is about 25$ without the battery charger!