:+1: It is surprising you got away with this comment, but it is so true!
Samsung is currently supplying 21700 cells to Jaguar, and is hoping to also supply two Chinese automakers, according to this 2019 report:
8 million a month, flashlights really are small fish for them. Thank you for the info.
day to day. (not recently) but I used to be in a suit most days. Usually that included a AAA keychain light of some kind and if I was doing retail with basement, or construction site tours, I would grab a 18350. Not even an 18650.
I have a PL47 on the way and it looks small so maybe I’ll try that and update.
For what most people use day to day, that’s more then enough. But I’ve lived through a blackout (our building only, flooding made FD cut the power to avoid getting electrocuted) where the windowless hallways were black once the emergency lights fizzled.
Just going to the community can and back, sure an AAA light would suffice, but if I were stuck somewhere that I might need decent light for a few hours, I’d definitely make sure to have a bigger donk at the ready.
And if we ever had another blackout like the one that killed the whole eastern seaboard, damnedstraight I’d want enough firepower to last me a while.
A twisted part of me almost wants another blackout, just to be able to use all my toys. 
Pff… not for the headlamps.
Unless it’s for those with a separate battery pack.
I allready got a batteries and flashlights for AA, 18(3)650 and 26650. These standaards provide everything I need. From EDC to power hungry builds.
I don’t plan on investing into this new standard.
Also, depending on the light, eg, the C8F, the fatter tube just seems better balanced (both look and feel) and gives a better grip, and in a pinch you can throw in an 18650 and it’ll work. Won’t even need an “adapter tube” for it, as if you’re really anal-retentive about the chance of the cell rattling around inside, a quick wrap with a napkin or tissue will take up the slack and even provide cushioning.
It’s already a decent-sized light, so the difference won’t be as much as an 18650 tubelight vs its 21700 equivalent.
This post confused me on first read. You say you wouldn’t want to use your edc for more than 2 hours. Then, you wouldn’t buy any 21700 light because you wouldn’t use the capacity. I initially read that as 2 separate points but I think you intend them to mean the same thing. It highlights how differently we use our lights.
Certainly, on a typical need basis I can make an 18650 last weeks or months. I can get by with a minimum amount of light. On a recent 6 night camping trip I had an AA headlamp and 18650 light and didn’t exhaust a single battery of either with lots of use.
On the other hand I like going for walks in dark, solitary trails. 20-50 lumens is enough for almost anything I do. Maybe less. However, even 1,000 lumens doesn’t eliminate the creepy factor. But 3,000 of those units and I feel quite comfortable and let’s me explore some of the open spaces. I don’t need to do that but I can and I like it. And I like going out for hours. I can go through equivalent of several 18650 on a single walk.
^ I was replying to Ventsi from page 2. I see it didn’t quote.
Those of us with arthritis and other mobility problems have to keep the weight we carry down to a reasonable level, so I am actually needing to change from carring a 18650 light to carrying a single AA light. I might finally get a successor to my Zebralight SC52 XM-L. I’m looking at the SC53w. The cells larger than 18650 are definitely not a possibility for me for me now.
I’m liking my Rovyvon E300s Nichia as a home-based light - it is powerful and well-made, but too heavy for carrying on a commute.
Am I wrong to think that maybe 21700 is not as great as I had hoped? I jumped on the Thrunite TN50 but no one else is doing a multiple 21700 form factor. So far the Acebeam K75 and Acebeam K30 GT is perfectly fine with 18650 batteries. The BLF GT70 is also fine with 18650 batteries. I’m starting to think that the 4x21700 is a bit too thick, and the 21700 is only a huge advantage when used by the thousands of cells in a massive battery pack in the Tesla Electric Car? Ha-ha. Maybe the manufacturers outside of Thrunite hasn’t caught on yet. Or maybe the 18650 is perfect and the 21700 is just a little too big for a 4 times form factor; for flashlights? Why has no one manufactured a 3x21700 flashlight yet? -the thoughts of a flashlight aficionado.
Why does there have to be a one-size-fits-all solution? We have different battery sizes for different applications and preferences. This is a good thing.
You are so right, Rayoui. I think it’s just the recent releases of the excellent Orbtronic 3120mAh 30A-40A, Sony|Murata VTC5D, Samsung 24S, and other fine 18650 offerings have kept me captivated. 
Cheers!
Nah, we should create a new battery size that’s in the middle of all of them, that will be a one-battery-for-everyone solution!
21700 isn’t enough of a size-dump from 18650 to make it worthwhile. Just enough to make it too big for EDC, but not enough to give a good boost to capacity. Yuck.
If you look at popular battery sizes, they all have a decent jump in size and capacity. AAA, AA, C, D. There’s a clear distinction in form and purpose. For lithium-ion, there’s already too much overlap. 21700 just makes that worse.
I like that I can buy a bunch of 18650’s, and use them in tons of lights. I don’t want a slightly different battery size for every light.
Then you don’t have use them. Like I said, different sizes for different applications and preferences.
21700 cells can provide much higher current than an 18650 while still maintaining high capacity. This is important for lights using boost drivers or throwers with very high-current LEDs. Good luck properly driving an SBT-90 light with a single 18650 cell.
For lights that I use around the yard or on the trails, I prefer the size of a 26650 or 21700 light to an 18650 light. Seems to fit better in my hand and the extra capacity doesn’t hurt. That said, my EDC lights are almost exclusively 18650. The 21700 is simply too large for a pocket light (though I do occasionally pocket carry my M2R Pro).
Sure, but the point of this thread is to imply that 21700 is going to replace 18650. If 21700 is the future, then the future sucks.