2AA flashlights: Why so few side-by-sides?

Can anyone tell me why so few 2AA flashlights are designed like the compact UK 2AA, with the cells mounted side by side to keep the light short? Is the thinking, "Well, with 2AAs, the light will be so heavy that few people would keep it on a keyring, so why bother?" If that's so, why is there no shortage of side-by-side 4AA models, with battery chambers just one cell long?

It could be a length issue. 2AAs lengthwise is a nice size to hold in the hand, while a shorter side-by-side configuration is a little short, and better for a keychain than a handheld light.

2AAs side by side are also oblong. If you want to fit them in a round aluminum body made on a lathe you'd have to make it larger and either waste the space on the side of the batteries, or just put more cells in there in a battery carrier of some sort.

I'd say it generally comes down to design decisions, and what market you're trying to hit. If you want a handheld light, you need it to be long enough and comfortable, if you want a keychain light, it can't be too fat and bulky. Plus if UK has already patented the best way to make a small side by side configuration, no one else can mimick it! /ubbthreads/images/graemlins/grin.gif

Just remembered another: Princeton Tec 20. 2 watts halogen, 2.5 horu burn time, $11 street price, six colors, optional flare cone, optional "L.E.D. module" ($35). The head, however, would make it too big for a keyring.

I have wondered this myself. After owning an eternalight, I find the "pager" shape to be very conducive to pocket carry and those use 3 cells... I much prefer 2 cells if I must use multiple cells at all. I would love to see a company come out with a nice "flat" LED light optimized for 2AA in side by side config. The UK isn't LED (if you use the eLED module, you get half output, and the bezel ruins the pocketability.) I would have gotten an eternalight Derringer if it was 2AA instead of 3AAA.

I think a lot of the problem with a side by side 2AA light is you just about have to make it out of plastic to get the cells in and AA cells are not much longer than AAA but considerably wider which makes for a light that has a bigger width the lenth ratio. I had a uk2AA light and the feel of it almost begged for a 2x2 version or the 4AA to balance the width/length ratio better.