18650
Zebralight SC62 is barely larger than my Solarstorm SC01.
I carry a Smiling Shark SS-5039 mod. to XP-G, 1.05 A and two mode geroups, but sometimes a very small 18650 as a pocket warmer. That one is now my Rustu R10, as my smaller and much lighter AKORay AK12 now seems too valuable to scratch up and my cheap very small 18650 zoomy is too ugly. If I expect to use it as a flashlight much, I carry a Sipik SK-73. It is no longer but has a bigger head.
how do you guys say to the fifth pocket in your jeans?
as far as i know it was invented to carry the pocketwatch 100 years before i was born 
but i say: Zippo-pocket cause i alway had my lighter in it when i was smoking since.
but now i have my S10R with clip in it (first of my lights that fits perfectly there!)
and i am not worried about scratching it with keys or my Cybertool
I keep my non-grocery shopping list in it, and sometimes other people’s door keys.
I’ll see if I have any lights that fit it, thanks.
When I didn’t have a band on my watch, I kept it there, but I didn’t put a chain on it and it broke when I dropped it on a tile floor.
I keep two spare 18650’s in it.
In the Netherlands it is called "condoomzakje" for some reason :-)
I don’t need an EDC, when I do carry one in my pocket it is a 18650 or 26650 (big pockets) however 26650 is my go to light due to the width being more comfortable for me to hold 
Cheers David
This thread reminds me that I need a good 14500 light - it’s a very under-appreciated battery format as it offers more capacity than 16340 while being slimmer.
I prefer to carry a 18650 because of the high capacity. High output is possible, but also long runtimes when using a flashlight in low mode. However i am also an advocate for carrying/owning an AA flashlight for emergy situations due to common availability.
/Offtopic
Although i’m from the Netherlands myself, i never heard of it being called “condoomzakje”. I myself was familiar with the term “vijfde zakje or horlogezakje” wich translates to fifth pocket or watchpocket. Btw, that doesn’t mean it isn’t commonly used as a “condoomzakje”. LOL
I don’t think you’ll see much difference in runtime for a 14500 vs a 16340, they are pretty even. And size wise you are only talking 2mm.
That’s what I’ve always called it, presume you mean condom pocket.
This was a really hard choice.
Current favorite light is the Trustfire A8 because it uses either the 26650 or 18650 or 3AAA so that’s a big plus in my book.
But…
I carry a Sipik 96 (clone) on duty as my back up light and have really gotten into the 18650 batteries.
But…
I EDC both a Rayovac mini-LED and Maglite Solitare LED on my keychain so both are always with me. And AAA is just a nice, common battery.
But…
I voted for the AA/14500. The Sipik 68 was my first venture into a CREE LED (a recommendation from someone on another non-light related forum who is also a member here, which is what led my here). And it was my first venture into batteries beyond the normal AAA/AA/C/D. In fact less than a couple of years ago I didn’t even know what a 14500 was! This type of format offers a light small enough to EDC that is bright enough for pretty much any task. And having the ability to use both li-ion and regular AA’s is of course a big bonus.
So that’s my vote