Is the 21700 format worth the move?

bykfixer

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John 3:16
When I was vaping the industry was deciding between 20700 and 21700 as an alternative to side by side 18650 steam machines. The bigger manufacturers were all in on 20700 at the time. I was using mini devices the size of a flash drive or carpenter pencil at the time but my brother was into the fog machines. So he was aware of the trends.

I say all of that to point out those sub-ohm (less than 1 ohm restistance) super suction fog machines could boil a 4 ml tank of sauce in about 10 drags so they were really taxing what a rechargeable was capable of. (Exploding batteries sometimes) Thereby developing products we can now use for flashlights.

I'm not going to replace lights for ones that run off 21700 cells, but am glad to see that size is now catching on little by little. I just hope the industry uses them to opt for better run time and not for more more more lumens with dismal runtimes.
 

Olumin

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Depends on the light. For small, 18650 sized lights, it's not necessary. But for larger, multi cell lights, I'd say it's worth the switch (especially in parallel configurations).

You could make the same argument for 26650s in that case, but 21700s seem far more versatile (I don't have any 26650s ATM). Going from 18650 - 21700 gets you an additional 1500mAh for just 3mm extra. 21700 - 26650 gets you only 500mAh for 5mm extra. Diminishing returns.
 

orbital

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As long as the batteries fit in my charger, I'm a willing to get different cells.
So if brand xxxx made a 25700 light with a 7Ah battery, great 'cause it'll fit in my charger.
Just NOT going to buy a new charger for it.

New lights aren't going to give you an option of either 18650 or 21700 size,
get a light for it's emitter, UI, and most importantly beam shape.

Weltool makes a 22500 cell & well:bowdown:
 

Hooked on Fenix

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For a headlight, I'd say stick with 18650 and smaller. For pocket carry, I like 16650. If you want a light with longer runtimes and higher brightness than you're getting from an 18650 light, invest in 21700. If you want a light over 2000 lumens, 21700 is the way to go.
 

3_gun

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21700 is my preferred format for my heavy use, work EDC lights but I have/use lights in just about every common size. AA/AAA/14500 based key chain size convenience EDC lights. 18650 lights in just about every class of light. 16340/18350/123a weapon & "jewelry" lights. Plus a couple full size (2C Maglite'ish) 26650/26800 lights for when a pocketable light isn't really a bonus/needed. The only format I work hard to avoid is built-in & proprietary batteries. [but I do have a couple]

In today's market I don't see flashlight as a singular sense like it was in the past. Today's LED lights + modern batteries they are more like a screw driver set. A blade & Phillips might be fine in a kitchen drawer but if you use a toolbox at work you'll have many sizes/lengths + specialty drivers (torx/hex etc) do do every job needed not just one.

So I have an EDC for at work in the field, at the office & for "just in case" on my time off. I have high CRI lights, mules, floody & throw lights & lights just waiting around for the lights to go out.

Staying with just one battery size would be limiting but in today's market if I needed to stay with just one format I'd give the edge to the 18650 (A 21700 is on my belt as I write this)
 

idleprocess

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I've been mulling it. The DM.12 has been fascinating me for many months now, however...
As long as the batteries fit in my charger, I'm a willing to get different cells.
So if brand xxxx made a 25700 light with a 7Ah battery, great 'cause it'll fit in my charger.
Just NOT going to buy a new charger for it.
... is probably the main thing holding me back. Neither of my chargers have the slack for another 5mm. And after 21700 there's the new hawtness the 26800 which like 21700 a few years back is also barely supported by any chargers. Lastly it's not like 18650 is holding me back in any meaningful way - I require neither staggering luminz nor hours of runtime.
 

KITROBASKIN

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Not worth the move for this house. For our uses, runtime is fine with 18650's. It was fun using multi-emitter flashlights for certain terrain and I purchased a 26650 host for that years ago.

If we were in a jungle environment where objects of interest are potentially higher up, then a wider, stronger beam could easily justify more battery capacity.

Now I prefer to carry a general purpose beam with a compact thrower backup because that is so handy for our neck of the woods.

Compactness and light weight (along WITH sufficient runtime) are at the top of the list, priority wise.

It is nice to have such options; didn't used to be that way for all recorded history until these last several years.

Now we can tune all those factors to get an ideal setup for the task at hand, Including the quality of light.
 

zs&tas

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Bigger power just needs 18650 X3 or x4 . Not just a 21700. For a decent runtime on a smallish light 21700's are real comfy in the hand. It's not worth swapping everything for them but if that's the light you want just get it . I've got one of them just wired magnetic USB chargers will do any singular battery , solves the size problem as it has no cradle.
 

idleprocess

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I've got one of them just wired magnetic USB chargers will do any singular battery , solves the size problem as it has no cradle.
Got one of those I had almost forgotten about.

If you are willing to buy from aliexpress, LiitoKala has inexpensive chargers that will fit a 21700 battery for $5 to $10.
I guess today I rediscover old purchases - got a couple Lii-100s that might have the margin to squeeze a 21700 into.
 

Hooked on Fenix

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Every time I grab something thicker than an 18650 light, I notice that I dont like the bigger form factor.
1*18650 light + a spare cell wins any time.
You must not have a Nitecore E4K. That light is the perfect size for getting a good grip and the large side switch makes it easy to operate. The user interface is a different story.
 

gunga

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I recently received an Emisar D4k. An outstanding, compact 21700 light. I find it fits my hand a touch better than the D4v2. It also seems more balanced as the head of fairly wide (identical in both lights).
 

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Labrador72

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Not for headlamps as the added weight exceeds the acceptable limit for my uses.
For flashlights though, 21700 can offer more lumen with longer runtimes in a relatively compact package.
 

Megalamuffin

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21700 is awesome for a work light. Currently I have two 21700 lights, zebra sc700d and fenix pd36r. Both of these are ideal choices at work when I know I'll be using the light for long periods at a high brightness.
 

Jean-Luc Descarte

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21700 for me. I'm big with big hands, so the larger and heftier form factor feels consistently better on my hand. 18650 models are almost too dinky.

Marked exception for headlamps, though. 18650, IMV, is the Goldilocks power/bulk/runtime ratio and will remain so for a long time.
 
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