In this case I built a flashlight with a 50W 3V LED

I get the LED recicling a damaged LED 50W 36V. To convert the LED from 36V to 3V is here.

Step 1: Mounting the LED

First get parts: An aluminum heat sink, dissipating cream and an old flashlight.

I installed the LED by drilling holes on the heat sink, put some dissipating cream and fasten with screws. I made other holes for the wires.

Step 2: Installing the Battery Positive Contact

Solder a spring on a perforated plate project, then I soldered a pins that will support the contact.

I cut the plate and subjected to pressure in the heat sink, then soldered the red wire. This wire go to the +

I used an old flashligt base and cut It to fit in the guides of heat sink. I made a hole to pass the black wire.

As the chassis lamp is aluminum is enough that the cable do contact to close the circuit.

I added a bit of superglue to secure the base.

As you can see, the flashlight lights up pretty well. I used a 3.7V 2000 mA rechargeable battery.

It stays on approximately 1 hour more less ;)