Post link 16 January 2016, 19:29
This is a modified version of the 100W LED flashlights on Instructables. I have looked at several of them.
Picture of 100W LED in PVC Flashlight

by jaksherry

While they look really great, none seem to have portability, and they all use massive, heavy, expensive batteries.

I developed this project over a few days while trying to make it more portable, using common rechargeable batteries.

Credit to:

This light does drain batteries rather quickly, and is really more proof-of-concept than actually useful as a utility light, but I really enjoyed designing this and putting it together. I hope you do as well, or at least get some good ideas out of this.


This device will use a high output voltage. BE CAREFUL! Basic safety steps (such as rubber gloves, etc) can be very useful.

This light is EXTREMELY BRIGHT, do not shine directly into someone's eyes. Trust me, it will hurt.

Also, it should be mentioned that rechargeable batteries carry a voltage of about 1.2V, while alkaline batteries are 1.5V. Do not mix these batteries or the resulting output will not match. This project can be done with alkaline batteries as well, and less batteries will be needed. But it would cost more $ long-term and you would be less green. Shame on you for even considering it.

UPDATE: I thought that I was not outsourcing the heat properly and some LEDs burned out, but what actually happened was that all LEDs work just fine. After reading the batteries with the multimeter, I see that this light works perfectly, but it does drain the batteries rather quickly. In the future, I will hopefully be putting out an instructable with an ungraded light output and more efficient heatsink.

Step 1: Supplies
Picture of Supplies

Tools List:

Small Flathead Screwdriver

Drill + bits

Rotary tool (like a Dremel) or Hacksaw

Wire stripper/Crimping Tool

Digital Multimeter

Dry Silicone Spray (optional, but worth it)

Soldering Iron


Heat shrink or Electrical tape


100w LED

44mm lens+ reflector kit

Colored Wire (red and black)

Step-Up Transformer

12V Power Switch, preferably lighted

Thermal paste

JB Weld Epoxy adhesive

12V 40mm fan+ heatsink

2” PVC pipe

2” Cleanout plug

2” Cleanout Adapter (2)

1 ¼” PVC Pipe

Two 1 ¼” PVC End Caps

4 Nuts

2 Bolts

2 Ring Wire Connectors

4 AA-to-D size battery serial converter to 4.5V

12 AA rechargeable batteries

The total cost for me was about $20, but I had a lot of this laying around except for the step up transformer and reflector kit. If you are buying all from scratch, it would probably cost closer to $35.

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