Need advice - 3D Mag, Conversion to 18650s

Firstly, this post may sound absurd, but please bear with me. I've been trying reading threads everywhere but the nuggets of information are all over the place, and for a first time 'modder' I can't make head or tail of much.

Secondly, I do not have any machining equipment whatsoever. Simple screwdrivers, pliers, yes. But not even a saw. Same for soldering etc. And my knowledge of circuits is pretty limited.

Thirdly, my intention: I am looking to purchase a 3D/3C maglite and change out the bulb to provide more light. Doesn't need to have extreme power. Why a maglite when I have a crapload of other lights around? The sheer size of the maglite. Sometimes, I want something with heft, and I don't want to carry my SR90 around (that's overkill!).

I've looked around, and from my own research I gather that my best option would be a Malkoff dropin. I'm fine with that.
However, I do not wish to use D/C sized batteries. Believe it or not, they ARE hard to find in my area. Since I have tons of 18650s, is there a simple way to convert the maglite to use them instead?

Does anyone have any other advice for me? An alternative route perhaps? I'm open to suggestions, but my budget is limited. This is not my primary or secondary light, so there it's not a priority.

Thanks in advance! :twothumbs

3d mag. will fit 3x18650 nicely, tle300 drop in, will give you 600-700lm, it also has 3 modes.
that is it. if you wanna go led, pbly the simplest conversion, no tools required. but it has to be d mag.

or if you wanna go hotwire, fm socket, metal reflector, boro lens, wa1185. and 3x18650, internal resistance of the tower, and tailspring should prevent from instaflash, of course soft start would help, simple inrush current limiter, will do the job, for a cost about $1.
a bit more complicated than led, but you can use 4c mag for that. (i got mag 85 4c, love the light), or 3d

I've fitted two unprotected 18650 batteries into a C-cell MagLite and all it took was a PVC sleeve, a spring from a Mini-MagLite tailcap (or any small spring will do) and some grinding on the inside of the tailcap to allow the spring to make contact with bare aluminum since anodized aluminum does not conduct electricity. The PVC used was 3/4" ID, turned down on the outside diameter by about 1 or 2mm.

On a 2D MagLite I've used the same 3/4" PVC pipe, used a coupler that I cut in half and placed on both ends of the light. The OD of the couplers is just smaller tahn the ID of the Mag tube. It's cheap and cost me about $1 to make.

Simple and easy: Malkoff drop-in + delrin sleeve.

A bit more complex: Heatsink + driver + delrin sleeve. Requires minimal soldering and sawing.

I can make the sleeve if you can't find one ready-made. I also do mag conversions, if you decide you'd rather have someone else do the modding.

Firstly, thanks all for your help. I'm starting to get an idea of what to do.

To keep it simple the first time round, a Malkoff - that's enough modding on the head.

I am more interested in the cells now.


alpg88
You mention a 3D mag will fite 3X18650 nicely. I went to the hardware store today and did a little scouting. Are you referring to them stuffed in end-to-end? If yes, It seems the 18650 is a a tad too narrow and there be a fair amount of rattle

"REFLECTOR -| -| -| TAILCAP"

Tekno_Cowboy
Thanks for your suggestion! That was what I was planning to go for before I started this thread. However, the 18650 issue was bugging me.

The delrin sleeve you mentioned, I managed to find it online. I am trying to find one locally though, and cant. Went round the whole evening in a hardware store.

If I really can't get hold of one, I'll probably get it off you (no other choice right?). But I'd like to find a DIY solution of my own if possible. Call it the thrill of fitting something together yourself.

PCC
Thanks for the suggestion of the PVC. I'm going to hunt for it soon. Yours seems to be the best bet.

However, alpg88 mentioned that 3 18650s fit just fine while in your case it was 2 18650s. Was it due to the sleeve or any other mods? I haven't bought the host (maglite body) yet, and am hoping to get it right the first time.

I AM planning to use this light to walk around so I don't want to have it fall apart while in use.


Thanks all!

well it is obvious you need some kind of sleeve, 18650 have 18-19mm diameter, d cells are 32mm, and c cells are 25mm iirc. when i said fit nicely, i meant lenghtwise

what i do is; i just roll up thick paper, no need for pvc, or any other exotic material. paper sleeve works great,

alpg88 said:

well it is obvious you need some kind of sleeve, 18650 have 18-19mm diameter, d cells are 32mm, and c cells are 25mm iirc. when i said fit nicely, i meant lenghtwise

what i do is; i just roll up thick paper, no need for pvc, or any other exotic material. paper sleeve works great,

Click to expand...

Thanks! You really made my day.

Why didn't I think of it before? Guess I was looking at something more permanent.

Member Britelumens, who is based in Singapore sells
both C and D sized 18650 spacers

tx101 said:

Member Britelumens, who is based in Singapore sells
both C and D sized 18650 spacers

Click to expand...

Thanks for the info lovecpf

chanjyj said:

PCC
...alpg88 mentioned that 3 18650s fit just fine while in your case it was 2 18650s. Was it due to the sleeve or any other mods? I haven't bought the host (maglite body) yet, and am hoping to get it right the first time.

Click to expand...

Well, I was putting two 18650s into a 2D MagLite, not a 3D MagLite. Had I been putting three 18650s into a 3D MagLite I would have done the same thing but with a longer PVC sleeve.

You might run into a problem with the spring in the tail cap. Some 18650s have shrink wrap covering the negative end of the battery except for the middle. With the stock tail cap the spring would sit on the shrink wrap and not make contact with the metal end of the battery.

Also, 18650 batteries are a small bit longer than D-cell batteries. D-cells are around 61.5mm long while 18650s are about 65mm long and protected cells are longer still. It's not much (about 1/8" or 3.5mm per cell) but it adds up.