3-18650 in series in a 4D mag means that you don’t have to cut the traces and rewire for parallel… it’s in series already and that’s close enough for direct drive…
For those stateside, use one hunk of schedule 40 white pvc pipe for the batteries, plus another couple of slices of the pipe to fill out the space. (I’ll post a pic if that’s not so obvious.)
Oh, but you do have to shorten the spring in the tail and make sure that it makes (-ve) contact with the body.
You are right! See how easy it is to get into a one track mind?
Or 32600s... 
After posting, I started to think about some of the explosive possibilities of series cells. So be sure to match cell capacity and level of charge. (And there’s probably other stuff I’ve forgotten to mention.)
Anyway, here’s a pic of the battery carrier (65*3 mm long), the (-ve) that drops into the tail, and my very beaten up 4D.
rather then cutting up reflectors would it not be easier just to use some of these optics as they look to be the perfect height
not sure if this one is aligned right or not for that board?
http://www.fasttech.com/products/1606/10002020/1187500-50mm-15-degree-3-led-optical-lensoptic-for-cree-le
Eh... I'm not in the 'cool kids' club I guess, I'm not really a fan of the TIR optics. Besides, I kinda like cutting things up.
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This may be common knowledge, I dunno... but that 3x XR-E board, in direct drive with 3 fresh LG 2200mAh 18650s in series, runs at 11.40v under load and at 2.66 amps.
So I ended up with a bulb with 4 Cree XPE Q2’s in it from banggood.com. Would it be worth it to use a driver for this thing? Any suggestions? This is my first attempt at modding a flashlight so I thought I’d start small. Here are some pics of the bulb, cost me $3.50. Figured I could get some good spread out of it.
Those don't look like any XP-Es I've ever seen...
Not even Crees.
-Garry
Yeah once I took it all apart I started to notice they didn’t look like the claimed XPE’s. Some pretty bad false advertising if that is the case, haha.
Here’s the link: http://www.banggood.com/Wholesale-Mr16-4w-360-lumen-3200k-Warm-White-4-cree-Xpe-Q2-Led-Light-Bulb-(12-V)-p-30816.html
Still think I’m going to try to make something useful out of it though, I just have no idea if the claimed specs are anywhere close.
Here is my mod:
Not a maglite, just a plastic 3D light that i paid $3 at a thrift store
led lamp from fasttech (ordered a $2.78 12v model with my latest order )
soldered a bit of wire around the negative spring to connect the leds
couldn’t solder anything to the positive end, so i stripped a wire and put it through the positive connector and spread out the small “subwires” so that the positive connection wouldn’t come loose easily, i hope this is enough 
i plan on using this light with AA-batteries, so i ordered adaptors from fasttech
AA to D
2*AA to D
will probably gift this to my father or my brother.
Thats thinking outside the box oscar! Nice!
Great job OscarM!
However not everyone should think outside the box…….
Oh, my poor bleeding fingers... this is just a test run to get the procedure figured out of how much to cut where, how to set the angle of the cuts so that adjacent reflectors line up, etc., and also to see if it makes enough light to be worth bothering with (it does). These were old scratched up reflectors and one doesn't match the other two so they don't line up just right, the geometry is just a little different on the inside.
Way to go OscarM and comfychair.
OscarM, I bet a lot of us have some of those plastic lights stashed away. I have a few that I was just about to throw out. I think I need to do your mod. Great way to have a floody light in the trunk of the car that you don’t have to worry about. Thank you for sharing.
That is brilliant comfychair. Cool way to get a 3 emitter set up with deeper reflectors than typical 3T6. You’re a true innovator!
Hey im new here and ive just ordered the 3x3w and was wondering if its ok to run it on 4.5v?
Thanks
Probably depends on the cells you use. Most will probably have enough voltage sag driving the 3 emitters that you should be ok.
+1
If you drill the star to break the trace, make sure you don’t put a dimple (pimple actually) on the opposite side. That will prevent good thermal contact to the heat sink. If you drill rather than cut the trace, drilling on a hard surface will help prevent the pimple. Also I have noticed that some of these come with no thermal compound between the star and the sink, add some if necessary. Lastly, when you put the TIR optics back together, be sure that everything is snug. The only thing pressing the star to the sink is the force exerted by the face plate, pushing the optics into the star.
Ok thanks for the advice guys!