Not to be Mr Glass Half-Empty, but I’m not sure just how practical a 2×AA light would be.
You’re losing the compactness of a 1×AA light, so it wouldn’t be nearly as pocketable.
You’re having 2 cells in series, which is dangerous for Li-ion cells (matched 14500s?), and using alkaleaks, you know one is going to drain faster’n the other and start leaking all over the place, turning the insides into a salt-mine.
With 2×AA, I’d rather use an 18650 light already, which would be shorter, yet have much greater output and runtime. Or just a 1×AA light with a 14500.
I got a few TK4As and SF11s which are 4×AA lights, tomato-paste-can lights. I already had an alkaleak brown one of the nice shiny brass nipples in the tailcap when it started leaking. Now, as soon as I see any drop in performance, I empty the light and use the individual (non-leaking) cells in 1×AA lights, watching them carefully. It’s a pain.
2×NiMH might be problematic, also unless you watch each cell. Low-voltage indication would get tricky, twin half-spent alkaleaks on turbo might drop to the 1.xV range, enough for at least one NiMH cell to run down well below 1V.
I’ve got two Quark 2AA-X lights that I stopped using because even though I love the twist-for-turbo head, “maximum” would steadily drop as the cells wore down. Can’t use a pair of 14500s with the low-voltage head, so I went and got the 1×AA tube for it. Still is a waste, as it still fades with cell-wear, and I still don’t use it anymore, now that so many other 1×AA lights (SP10/TK05/etc.) outperform it. It’s not very pocketable, and is a waste to holster.
I just don’t see any advantage to a 2×AA light over, well, anything.
And besides, 2wks after Manker comes out with it, there’ll be a UTorch UT2AA coming out. :smiling_imp: