DIY Maglite LED Upgrade Conversion 5,000 Lumen




Introduction: DIY Maglite LED Upgrade Conversion 5,000 Lumen

This tutorial will be on how to convert a standard 2 D Maglite into a 5,000 lumen LED light.
Very few tools will be needed. A screw gun or drill with a sanding tip on it is useful, but in a pinch a flat head screw driver would do the job.

Step 1: Step 1: Choosing Your Host.

Choosing your host size. Any D or C cell mag can be converted to do
this with a similar build. Today we are going to focus on making it in a 2 D size mag. Using larger hosts such as 3 or 6 D are probly less work, but I like the more compact size of the 2 D.

Step 2: Step 2: Choosing Your Battery Type.

Now its time to decide what batteries were going to use. The light engine for this built needs to have voltage equivalent to a 6 D cell. 6 NIMH D cells are a great option, but since we are going to build this in a 2 D size using a r of 3.7V li-ion 26650 are needed.. IMR safe chemistry cells are the best as the completed build will have a nearly 10 amp drain on the cells. Alternatively IMR 18650s or IMR 26500s could also be used.

Step 3: Step 3: Choosing the Light Engine

There are many dropin bulbs and heat sinks available on the flashlight market these days. For this build we will be using the Adventure Sport Flashlights™ 5,000 lumen drop in bulb. It uses 3 Cree XHP-50 LED emitters and has multi level brightness. It also comes in a 3 cell 2,000 lumen version, but we'll save that for another inscructable :)

Here is where you can get the bulb.

Step 4: Step 4: Installing the Bulb.

1.First simply remove the bezel, reflector and old bulb. You wont need the retaining ring that held the old bulb in place either.
2. Unscrew the head a bit ( just till the O ring on the neck shows)
3. Insert the drop in with the provided O ring in place
4. Replace the bezel (its highly recommended you use the optional high temp lens offered with the bulb)
5. Gently screw down the head until its just snug

Step 5: Step 5: Making a Body Sleeve

In order to keep the cells from rattling around in the body we need a sleeve. If you want a professional sleeve one can be purchased for the 2x 26650s here. They are a bore out PVC pipe with O rings around the outside for a nice fit. If you want to go cheap you could also just roll the cells up in a piece of newspaper. Also if you are using flat top batteries for this you will need a way for them to make contact with the base of the mag switch. A small magnet is the easiest way to do that. Just stick a couple to the + end of the first battery and your good to go.

Step 6: Step 6: Shorty Spring

Since the 26650 batteries are longer than D cells we need to make room by shortening the spring. You can cut some off the bottom of the factory spring and use that. Alternatively a shorter narrower spring is offered by Adventure Sport along with the sleeve. This also has a smaller tip which makes contact with the cell and wont rip the shrink at the edge.

This is where the only tools needed come in. Since the cap is anodized at the bottom you need to remove some so the spring will make electrical contact. An electric drill with a wire brush attachment works well, but if you don't have one you could just scrape some away with a screw driver or similar.

Step 7: Step 7: TIME TO PLAY!!!!!!!

With your build now complete its time to try it out. You have not successfully taken your light from having the output of a half lit match to a LUMINUS SHOCK WAVE!!

If you have enjoyed this instructable there are a couple videos in the picture section your sure to love.



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    32 Discussions

    Great idea... as long as you have power, However all is not lost, once the power runs out. keeping & Using the old reflector can start many fires on a bright & Sunny day.

    Another trick would be to alter the lens with a Fresnel?] lens,

    1 reply

    Thanks Qeuster. Maybe I will give it a shot with the fresnel :)

    Hi alby,
    Thanks for sharing your mod. The way that I get such a tremendous output from my lights like that is building an A+++ thermal path. Most LEDs are attached to an aluminum mcpcb. My emitters are reflow soldered directly to a copper MCPCB and then mounted on a heat sink. Also using three of the Cree XHP-50 emitters means I have a total of 12 LED dies. This is a very very efficient way to generate light. In total this build is about 80 watts. This means about 62 lumens per watt on the high mode. Efficiency will go up very far on the low modes. Up to around the 300 lumen per watt.

    I hope this helps. If I have not answered your question correctly please let me know :)

    Fire, good! Have you done any testing on your heat sink performance installed in the maglite? How about luminous output over time (single cycle and multi-cycle)? With your stated 80 watts, and assuming that your drop in housing moves heat out of the LED's at 1 degrees C/W added to the LED die junction to solder pad resistance of 1.2 degrees C/W you are talking a 176C rise in die temperature within the engine before any heat transfer to the maglite housing. Since the maximum recommended junction temperature for these LEDs is 150C, and your instructable does not appear to suggest the application of a thermal compound to the engine drop in prior to installation into the maglite housing my guess is the luminous lifetime of such a light engine is limited. What can you tell us?

    Hi jmengel,
    I have done some testing with the output vs runtime. The rating on the 5k and 2K bulb is what is to be expected around the one minute mark. You dont have to use a thermal compound in the head of the light, but you could if you wanted to. On the higher modes the output is going to decline some as the head of the light heats up. A general rule of thumb to protect high powered light engines like this is when the head of the light gets too hot to touch you need to turn it down. In the lower modes the output will be fairly linear. There will be some decline in ouput as the batteries die, but visually you will not notice much of a drop off at all. These bulbs come with a 5 year warranty.

    However if you take care of them properly the life expectancy of this type of engine will be much longer. I have never had an LED engine die of old age before. The reason I always replace LEDs is because a new brighter one is being sold and the old ones are obsolete. Hope this helps.

    Do you think this would be possible with less lumens and a magnifying glass?

    4 replies

    Hi Polymathic,

    Yes. I have done similar experiments with small pocket size lights that only output around 1800 lumens. The effect is a little slower, but either build will make smoke INSTANTLY. I just have hard time starting a fire from an ember so I went with the larger light. Using a magnifier may help. I was not able to do any better using one but I did see a video where a guy used one. His vid only produced smoke (accept when he used matches), but I think it could be done.

    Skip to the 8 min mark if you wanna see the lens think skip to the 8 min mark.

    Thanks for the info. I may give it a try this weekend!

    and I would try getting a cotton ball to when you point ur light at it not an ember

    Hi Yonatan,

    Thanks for watching. The 5,000 lumen rating is the true tested output measured in my integrating sphere. There will be some variation between bulb to bulb, but using the setup I have displayed 5K is the real benchmark.

    Somehow I found the idea far more intriguing before I realized that the entire project hinges on Step 3: Buy a bulb from the author's company for only $94!

    A little more focus on alternatives methods, and a little less on "look how great my product is! (Psst! You can buy all the other components from me, too!)" might help it feel more like an Instructable and less like an ad for Adventure Sports Flashlights.

    3 replies

    LOL! Thanks for the comment batcrave. I see your point. Really I do. I suppose I could expound on building a light engine like this from scratch vs picking up a ready made bulb. I just didn't think too many folks would be interested in making it if step 1 is buy a lathe. Good lux with your projects :)

    Funny you should mention that... I've spent the past few months working on building a CNC router (originally based on another I'ble), and right now the next step in the project appears to be "buy a lathe". It's definitely a bit of a stumbling block (anyone out there got a lightly used South Bend Heavy 10 collecting dust? wanna carry it down to my basement? I'll give you beer!).

    And to be fair, the drop-in is a rather impressive looking little beast - and I'd actually love to see how it's put together, whether or not I have the tools to duplicate it (because I don't spend nearly enough of my free time reading about how to do things I don't have the tools for. honest!)... It was just a little frustrating to see the title, start skimming for the construction & circuit details, and then find that all the exciting bits are hidden away inside the shiny metal shell of an proprietary component.

    Man I'll tell you this. You wont regret getting one. They really are a blast. I had to get a cheaper China made one but it's still great. I don't have any pictures of the inside of the light engine yet, but I don't mind sharing whats inside of it.

    The inside part is 3x Cree XHP-50 LEDs on a copper mcpb.

    You want them wired in parallel for this build.

    The lens is a Cute 3 optic, but there is only one that works properly. The XM size hit the domes of the emitter so you need the XRE version. The medium beam angle works the best. The narrow makes a hole in the center of the beam and the wide is kinda distorted.

    The driver board is a custom one. Its the MOSFET driver from my shop. They are not too hard to make if you have the stuff but it would take more than one post to elaborate. If you dont need modes you could just wire the engine direct drive off the batteries.

    Good lux with your projects.


    The Instructibles mentions a "Fire starter" flashlight. But the Instructible doesn't go there ?