14500 / 16340 / 18650 / 21700 / 26650 which format & why

3_gun

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I've found myself very much in the 21700 camp with my latest shopping so much so I start with that in my search limits over everything else. Nothing else matches the the combination of body size, run time & lumen levels in a package that is still GP, bike light, weapons light & EDC possible. Plus many lights can still use a 18650 &/or some variant of a 16340 for versatility.

I don't mind having 14500 availability in a AA sized light. A bit more "punch" from the compact EDC sized AA lights is nice when you have access to both. I don't see the AA format going away .. ever.

18650 are pretty much the standard go to format for any serious light & with very good reasons. Still for just a small jump from 18 to 21mm you get a big jump in power; 3500mah to 5000mah. Not everyone will want or need that increase so I don't see 18650s losing much market share but I think we'll see some.

So what am I missing about the 26650 format. What do you gain over the 21700 format that isn't offset by an even bigger loss due to size or weight. You only gain about 500mah & you get a size that doesn't fit most mounts & isn't easily pocketable. Have I missing something? A use in tool/automotive battery packs maybe?

I have the feeling we are on the edge of a market shift. I can see 21700s taking over the main stream LE/EDC/work/GP lights with the 18650s being left to more the compact, home & convenience market. 14500 will continue to give a boost to the light duty AA EDC lights.

So where does that leave the 16340 & 26650 formats to go? I doubt they will go away but I do think there will be less of a market share & less development as we move forward.

Have I missed something?
 

Poppy

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I believe that the ubiquitous 18650 will be here for a long time to come, but I agree with you that we will see more usage of the 21700 cell. Primarily because Tesla is using them in his cars, and that will drive the cost down due to increased mass production.

I don't own, any 21700 lights, so I can't comment on how I feel about the size. I do have a couple of 26650 lights. They are pretty big head throwers, so the heft of the larger body seems to be in balance.

There are three lights that I have that I think are elegant. I just like they way they feel. One is the maglite 2AA Pro +, one is the EagleTac D25A2 mini, and another is the Thrunite 2C (it takes a 16650 Li-Ion cell). I'm not sure if the 16650 cell is produced anymore, those that are available are about 2x the cost of an 18650.
 
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novice

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At the time that I got Fivemega's 1x26650 E-head, and his 2x26650 C-head, 21700 were not in very common usage. The 1x26650 body feels surprisingly good in the hand; I have a Nitroz-modded E2L head on it. If I wanted to use a Surefire incan lamp assembly in a SF turbohead, the 2x26650 body would be what I would reach for.
I really want Fivemega to make a 1x21700 E-head custom body, and a 2x21700 C-head body; I would buy both. Of course, that means that I will need a new charger. A slightly longer version of the XTAR VC4, please.
 

chip100t

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When wearing jogging pants I pocket carry an 18650 light, but when wearing Jeans I will go with a 16340 in my watch pocket as it frees up my other pockets for all the other stuff that I carry. But if wearing a big coat or carrying a bag I will go with a 21700 light.

I have come to the conclusion I own too many lights so try to stop myself window shopping on the internet. I find despite owning many I seem to gravitate to the same 3 lights, 1 in each of the formats as stated above.
 

UFO

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As with the ocean, there is a certain "ebb & flow" to life, and that includes just about everything, like fashion styles, hair styles, and music. There very well may be a "shift" as you say, however the other formats will not disappear, they'll just sit on the back burner for awhile.

I must admit though, when I bought my first two 21700 lights, I thought the very same thing. Glad to know I'm not alone in that observation. Interesting thread.
 

n2mb_racing

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I don't think 21700 will make sense for headlamps. 18650 is already pushing the limit in terms of weight, I think. I don't like running with my Fenix 65-T as much as my Zebralight H52 (14500) headlamp.

16340 might be good in headlamps, like the Fenix HM50R v2.0, but the format doesn't seem to have the capacity density that 14500 cells do.
 

fuyume

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Well, Fenix clearly thinks that 21700 is going to be fine in the new HM70R, though it does have a top strap. I don’t really think you’re going to see a whole lot of people using that while running, but for people who need a lot of light for a long time that has to be hands-free, I think they will be willing to put up with the weight.

21700 is clearly the high volume battery of choice, now, replacing the 18650. It’s the size adopted by Tesla for the Model 3 and the Powerwall, as well as being marketed by Samsung and LG for use in electric bicycles.

I went with the 21700, because of the significant improvement in runtime over the 18650. It’s not too large as a single cell for a handheld flashlight, and I have my single AA flashlights for EDC and backpacking use, where/when weight must be kept to a minimum.
 

Olumin

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I really like 21700. much more cap. with only slightly larger size, I think its the way forward. If you need small AA is still a thing and 18650 wont go anywhere. I just dont like how I cant use my 1" holster with them 21700 numbers. Like most 18650/cr123 are uniform 1" body but 21700 is still all over the place with size.
 

High_Noon

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The 21700 is likely the future. My last light was a TX Lumens, which I ordered before the 21700 became popular. I had them build the light for a 20700 cell, which are now difficult to easily find. Capacity seems to be fairly enormous, though - I don't use it every day, but may have charged it only once in the last 4 years.
 

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