I picked up the light at a vendors mall. My motivation was to simply find out if the light worked before I invested in D batteries. 4AA batteries are about 15mm longer than 3D’s. But Maglite has 12mm of room behind the spring where they store a spare bulb. I rolled up a cardboard tube then stuffed some copper wool behind the spring. The AA went through the center of the spring. The previous owner upgraded the bulb to a LED. It is possible to put in 8AA batteries but not 12. The tail cap has a smaller diameter. I’m going to run this for a while as my bicycle headlight. An inner tube will be stretched over the body and power button which will give better sealing. Then the light mounts in conduit clamps. I get any water in the lens I will give the light away. This light is exactly what I wanted. A low power light with enough battery power to run all night. There is 213mm of room without the spring plus 2mm of recessed room at the positive end. The tail cap inside has a diameter 28mm in case some one wants to try something different.
Or… just get these:
https://www.amazon.com/dp/B074PKPPNS/
I forgot why I originally got these, probably something along those lines like what you’re trying to do.
They’re all in parallel, so you could stick 1, 2, or all 3 in each shell.
Plus, you can fidget with them, so if you have 2 brand new AAs you can stick 1 each in 2 shells, and take 2-3 worn-down cells and stick 'em in the 3rd shell.
Sure you could put 9 in there but I think 8 would out perform 9 since the regulator does not spend any time in boost mode. Like I said 12 won’t work since they would have to extend into the tail cap. I was thinking along the line of 3 26650 sodium ion batteries.
you can put 12 in 3D light, 3s4p, thou it wont really help you much, i’ve done it before. 4AA in parallel is actually better than 1D, similar capacity, better power, less sag undr load, and lighter, AA cell is about 25G, D cell is about 160+G so 4 will be 60 gram lighter, 12AA have same weight as 2D cells,
You could even connect them almost anyway you want basically, if you 3d print contact discs, and pay attention how you load them.
However all of that is obsolete now, 2 LiIon cells will replace 6 alkaline cells, and weigh as much as 4AA cells, with 50- 75% more capacity.
Not to mention 4AA won’t fit unless the tube is bored out
Those adapters are in parallel. So they have the same voltage as 1
they sure will, try them, the idea is not to use conventional holders at all.
I posted pictures of that, pretty much every brand of AA fit; alkaline, lithiums and eneloops, thou some you need to turn the wrapper seam inside, unfortunately photobucket deleted them a decade ago or so