How to get 4 26650's in a 4D Mag?

[Stereodude]

What are the tips and tricks to fitting 4 26650's in a 4D Maglite? Is it just a matter of shortening the spring by ~15mm and using some PVC pipe or rubber hose around the cells as a spacer or is there more to it than that?

 

[mrartillery]

You will need 1 inch pvc pipe cut in half long ways to keep them from rattling, and for the length, I think you will need a extension, but I am not 100% positive on that. 2x26650's will fit fine in a 2d, but a 3d you will need a 65mm FM extension, so a 4d.... :thinking:

 

[Stereodude]

You will need 1 inch pvc pipe cut in half long ways to keep them from rattling, and for the length, I think you will need a extension, but I am not 100% positive on that. 2x26650's will fit fine in a 2d, but a 3d you will need a 65mm FM extension, so a 4d.... :thinking:

4 28650's are only ~15mm longer than 4 D cells (total). There has to be at least that much extra length in the light either by shortening the spring or removing the anodizing from the tail cap and relocating spring into the tailcap.

By my quick measuring with my calipers it looks like I can probably save ~8mm by cutting off some extra turns in the spring. I guess I need to do something else that will save more.

 

[Kestrel]

Conte has a thread with some ingenious Mag tailcap mods here.

My favorite was using the spring from an old 6V lantern battery nestled inside the Mag's foam bulb holder. Using the positive cap from a D alkaline cell was cute as well.

A very slick mod I saw elsewhere was using a lathe to deepen the spring seat/shoulder in the tailcap so the stock spring sits deeper in the tailcap - looked very very slick.

 

[Stereodude]

Conte has a thread with some ingenious Mag tailcap mods here.

Thanks for the link to that thread. :twothumbs

 

[Mettee]

just sink the tail cap, it will work. If you need that done send it to me I will set you up for nothing. I fit 3x26650s in 3D mags all the time, 4 is no diff.

ETA: I even have the right PVC to fit the cells.

 

[Justin Case]

Fitting the extra length by trimming the tail spring and installing it at the bottom of the tail cap is fairly easy.

Incrementally trim coils top and bottom from the spring until you get acceptable fit. Cut the spring wire with some big diagonal cutters. File the cut ends smooth. Bend the end of the top turn so it fits inside of the IMR's orange wrap.

Use Liquid Plumber Gel to deanodize the inside of the tail cap. Pour in the gel straight (no need to dilute), let stand for about 15 min, rinse out the gel with water and wipe the softened anodization out with a gloved finger. If any ano remains, repeat with more gel for a few min.

No need for sanding,
scrubbing, or wire brushing to remove the ano.

 

[Stereodude]

just sink the tail cap, it will work. If you need that done send it to me I will set you up for nothing. I fit 3x26650s in 3D mags all the time, 4 is no diff.

Thanks for the offer. What do you mean by sink? Using a lathe to cut a new shoulder so that the spring sits much deeper in the tail cap?

 

[Bob96]

Do the same techniques described also apply to using 3 X 26500 cells in a 2 cell D Mag. ? Just shorten, or remove, the tailcap spring?

 

[alpg88]

easy, i fit 4x18650 in 4d.
http://www.candlepowerforums.com/vb/showthread.php?t=276552

 

[mrartillery]

Do the same techniques described also apply to using 3 X 26500 cells in a 2 cell D Mag. ? Just shorten, or remove, the tailcap spring?

For this I just use a dremel and grind the shoulder off the inside of the cap and cut the bottom 2 rounds off the spring, then press the spring in the tailcap with a flat blade screw driver, do the same for my 3 D with 4 IMR 26500's.

 

[Justin Case]

Do the same techniques described also apply to using 3 X 26500 cells in a 2 cell D Mag. ? Just shorten, or remove, the tailcap spring?

The method I described in post #7 works fine for 3x26500 in a 2D Mag.

 

[mrartillery]

Bob, this is the tailcap from my 623 (as indicated in post 11) this is the solution I prefer the best.

 

[Mettee]

Thanks for the offer. What do you mean by sink? Using a lathe to cut a new shoulder so that the spring sits much deeper in the tail cap?

yes. And I can do some other special tricks if you want this to have little to no resistance.

When I say sink...I mean drop it down deeper into the cap. It can go almost all the way down. I typically cut the spring down a little as well and grind the wire so the spring sits flat again top and bottom. Sorry I don't have a picture of it, I am sure you would like what I do. Then I make an Al pill and press it into the top of the spring to protect the battery from damage.

You may ask why would I offer to do it for you, cause I can do it for you. I want people to be able to enjoy modding and be able to get the good stuff without getting screwed over. Its really no skin off my back to help out. Its a simple job and I have a fixture setup already so...I figure for $4.50 shipping both ways you would like what you get back :rock:

 

[Stereodude]

You have to cut the larger diameter portion of the spring off to get it into the tailcap right? (or is there another trick to reduce the diameter of the base of the spring?).

By my measurement, the spring is 1.3" in diameter and the tail cap opening is 1.13".

 

[Stereodude]

Do the same techniques described also apply to using 3 X 26500 cells in a 2 cell D Mag. ? Just shorten, or remove, the tailcap spring?

I'm not sure. Two D's are 123mm long. Three 26500's will be at least 150mm long. That means you need to allow for almost 27mm extra of length.

On the other hand, four D's are 246mm long and four 4000mAh 26650's are 261.32mm, so there's only an extra 15mm of length to accommodate for.

 

[mrartillery]

I'm not sure. Two D's are 123mm long. Three 26500's will be at least 150mm long. That means you need to allow for almost 27mm extra of length.

On the other hand, four D's are 246mm long and four 4000mAh 26650's are 261.32mm, so there's only an extra 15mm of length to accommodate for.

Check out my picture in post 13, this is what I use to account for the extra length of the batteries.

 

[Mettee]

You have to cut the larger diameter portion of the spring off to get it into the tailcap right? (or is there another trick to reduce the diameter of the base of the spring?).

By my measurement, the spring is 1.3" in diameter and the tail cap opening is 1.13".

Yes and no. I do reduce the diameter but I also press in the spring so its really in there. I twist it up to reduce its size then release it inside the tail...if that makes sense. Then the pill of Al on top. Then if you want I thread the pill and run heavy wire from a type if set screw feature to the bottom. Its pretty simple and takes hardly no time but it is super clean and works the best, and for longevity it holds up well.