4D Mag V4.0

Flashlight Modding and DIY Parts
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I love Mag-Lites, I know they’re a bit anemic by today’s standards but back in the day there was nothing that could touch them for the average guy. Even now they make good hosts.

My collection of D Mags started long before I had any idea I had a problem. The first indication of my affliction came a little over 10 years ago. While unpacking after moving to my current home I realized I had 1 5D, 1 4D, 3 3D, 1 2D and a MagCharger. I guess I just never had them all in the same place at once. This post is about my trusty old 4D.

V1.0 was a simple incan.

V2.0 was when the drop in LEDs came on the scene. I put either Mag brand or TerraLux drop ins in all the Mags and thought they were fantastic, a little brighter, better beam and run time off the charts.

V3.0 (by this time I was resigned to my problem and reading forums…) Malkoff XP-G along with a Rebel reflector. I had to cut the switch down to fit the reflector, first modification (not counting drop ins), I was hooked.

V3.5 was swapping an XP-G2 3C onto the Malkoff.

V4.0 completed this morning.

About 6 months ago I got lucky enough to purchase a heat sink from Moderator007.
I filed down a Sinkpad and flowed an XM-L2 1C on and mounted it to the heat sink.

For the driver I used a standard Nanjg 105C set up for 3 modes, 5, 30, 100% and stacked 8 more 380mA 7135s.
I added a copper disk to the 7135s on each side of the driver. I have no idea if that will help with the heat, especially with the driver just sitting in Fujik but it makes me feel better.

The light is powered by 4 Tenergy NiMH D cells. They claim to be 10,000 mAh but I doubt that, I think I saw a review somewhere that put them in the 8-9,000 range and that’s fine by me.

Lets get to some preliminary numbers, first voltage under load (sorry for the poor pictures).
Low

Medium

High

YES! 4.8V on high, well above that dreaded Vf of the XM-L2. Granted, the batteries were freshly charged and photos were taken after only a couple of minutes run time but there’s a lot of head room there.

Lets take a look at tail cap amperage.
Low

Medium

High

Very Happy! :bigsmile:

I have both smooth and stippled Rebel reflectors for the light. The stippled reflector actually gives a fair amount of usable adjustment between flood and spot.

A couple of photos with a sibling.

I haven’t had a chance to test it out much yet, waiting for the night. It will be interesting to see if it all holds together, I may fry the driver the first time I push high for more than 5 minutes or so, may fry the LED under the same use or may even melt the reflector. I can’t wait to find out.

If I can limit my use at 6A to short runs I think the 1.8A medium will work very well. Unfortunately I don’t get much use out of the old D Mags this time of year, they head up north with me in the summer for boat use.
Hopefully this one will still be working when the time comes, otherwise I’ll have to start planning V5.0.

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Nice build Itinifni :slight_smile: Mags still have a feeling of nostalgia IMO. Take a true American classic, mod it, and you have yourself a sleeper light.

With 4 Nimh cells used to power a AMC7135 based driver you might run into some trouble. Excess Vin above the LED Vf will be dissipated as heat through the larger ground tab. According to Match’s testing a XM-L2 at 6A wil have a Vf of roughly 3.9v. With a Vin of roughly 4.8v the driver will be dissapating (4.8-3.9)v X 6A = ~5.4 watts of heat. Take a look at TechJunkie’s build over at CPF for further details.

He had to resort to using resistors to burn off excess Vin (Vbatt) in order to prevent the AMC7135 chips from overheating and throttling output. Your potted driver may or may not be able to deal with the heat, only one way to find out.

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Awesome mod! Do you know where I might find a drop in heatsink for a mag like the one you are using? I don’t have any sort of machining capability, but I’d love to do something like this sometime.

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I was aware of that possibility but decided to go ahead with the build anyway, like you said, only one way to find out.

I gave it a 5 minute run tonight, didn’t seem to dim at all. And I very happy with the output!

On an unrelated note, this is the first time I’ve used a Nanjg 105C (usually use the KD V2 or Q-Lite), now I know what everyone talks about regarding the high pitched whine. This will be the last 105 I use.

I’ll update if the light goes south.

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H22A over at CPF sells them, I’m sure there are others out there too.

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Oh my. That's a serious frickin light you built there. And you have a smooth Rebel reflector for it too? Congrats.

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Thanks!

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I’ve ordered a few heatsinks from britelumens, depends what you’re looking for and what they have in stock, but the quality on the three I’ve gotten has been outstanding. Keep in mind you’ll have to get rid of the plastic post that holds the stock bulb/led, and solder some leads to the switch housing.

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On what? The pics look fine to me.

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I built something similar using 1/2 d cells I think I had 12 7135’s. with fresh batteries after a few minutes it would start to crap out and act flakey. the 4 big cells were just too much for the 7135

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I'm using two Mag4D XM-L lights, each are using 4 high capacity NiMH cells. Driver is a NANJG 105C 3.04A. I mostly run them on high and never had a problem with the driver. Note however that both drivers are fully potted and heatsinked.

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Good to see you getting some modding in.

The 105C does like to whine, but I find making sure of a good ground makes them go quiet. Mag switches don't always ground very well. It may help to simply loosen and tighten the set screw in the switch several times, to "seat in" the screw into the body better and get a better contact. Make sure the driver ground wire is soldered really well too.

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Very cool. I really love Maglites! Had so many over the years… They were so cool growing up with them over the years. I know the old models are out dated, and I have many newer brighter lights, but Mags always hold a special place with me.

Lost several due to alkaleaks and lack of battery knowledge. Now knowing better,I have resurrected a couple with glass lenses and LED upgrades. I look forward to learning more and doing some serious upgrades.

Thanks!

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The 'old' Maglites are still great hosts for modding. I did all kind of mods using AA, C and D size Maglites. For the bigger lights they are still my favorite platform.