Interest in a 16650 light?

Would anyone be interested in an EDC based on a 16650 battery?

I am on the hunt for the perfect EDC and honestly think a light designed around a 16650 would be the optimal starting point. It seems like the perfect balance of size/performance between a 14500 and 18650 light. I do realize that some people do EDC 18650 lights just fine, but I believe most people find them a bit fat. I currently EDC an Eagletac D25A and as much as I like it, I really wish it was a bit.... well.. more. The size of the D25A is so slim that I don't even know I'm carrying it unless I check. I would be willing to go a bit bigger for some better performance, but even the slimmest 18650 lights are too fat for me.

So here is what I've discovered so far.

  • 16650s seem to be readily available since they are used primarily in Surefire lights as a rechargeable solution where an 18650 won't fit without boring the tube out.
  • The slimmest 14500 light I could find is the D25A that I currently carry at 17.5mm
  • The slimmest 18650 light I could find are quite a few Eagletacs at 22.5mm
  • The Maximum capacity for each battery type would be, 14500 @ 840mAh, 16650 @2500mAh, 18650 @3500mAh

Now the obvious choice here would be to look at 16340/CR123 lights since they would hit that 16mm battery diameter sweet spot. A search of these lights that return results near the middle between 17.5mm and 22.5mm would be a single light. The Eagletac D25C2 Mini at 20mm. (No tail switch though) I have read that this light can accept a 17650, so it could be slimmed down even more to be 19.5mm. I realize that not every single light out there is listed on the parametrek site I have been referencing, so I'd love to hear of any lights I may have missed. I did ask on reddit if anyone knew of other 16650 lights I may have missed, but nothing fit the bill.

I would think you could get 1k+ lumens from a 16650 light that was no larger than the target 19.5mm, but I could be wrong. I also realize that there are serious thermal considerations in a light that thin pumping out that much power, but I would be fine with a quick step down. I would think a full minute at full power wouldn't be out of the question, which would cover most of my own use cases.

So I'm sure I haven't considered everything which is why I'm posting here. Is this just a pipe dream that no one else would be interested in, or are there other factors that would just make the effort not wort it? I'd love to hear some other points of view.

I got different 18650 lights

The lightest is 44g but an angle/head light

For tubelights with tailswitch they are mostly with a relative thick tube
Around 100-130g

If you would design a light with a pretty thin lightweight tube like my Skilhunt H03R and a smaller reflector than 25.6mm light this would be perfect

I tend to like high-powered pocket rockets.

The only problem with 16650 was last I looked I couldn’t find an IMR 16650 from a reputable brand. There’s an ICR 16650, but not an IMR one.

Without an available IMR cell, 16650 is just not that appealing. If I want a max output pocket rocket, I’d get better results using a smaller IMR 18500.

Can you design a 18650 light that weights with battery less than 100g and run protected cells?

I didn't consider an IMR cell, so I'm glad I asked here. I linked the 16650 test by HKJ above. Can you guesstimate the kinda performance you might get from that cell?

I would love a pocket rocket as well, but if I could get a noticeable performance boost over a 14500 I would be delighted. I would agree it wouldn't be worth the trouble if the performance wasn't much better than a 14500. At that point the only benefit would be longer run times.

Eagletac seems to make the thinnest light in the business AFAICT. They have the D25LC2 which is an 18650 light and is only 49 grams. Not sure if it will run protected cells or not though, or how much weight the battery would add. Guess it depends on the battery.

For my needs, I'm less worried about weight than girth. I wouldn't like to carry an anchor in my pocket, but I couldn't imagine a 16650 light weighing more than an 18650 light.

I agree that a 16650 light could be a good compromise between capacity and girth for EDC. There really doesn’t seem to be much selection of 16650 cells, at least that HKJ has tested. That keeppower cell you linked has a fairly high internal resistance, so it would not perform well compared to high discharge cells in a direct drive setup. But for most lights that are current regulated in some way I think that cell would perform fine.

You could get relatively high performance in a 14500 light if you choose the right cell and setup, the capacity will always be low, though. I just recently got a thrunite T10 after EDCing a convoy S2+. The ~18mm width of the T10 is nice, especially with certain pants pockets (I carry clipped to inside front pocket). I’m planning on putting a FET driver and dedomed XPG2 in there, with the windyfire 14500 cell. From HKJ’s tests, this cell is the best available 14500 cell around (lowest IR). I expect it to do around 3.5A at full charge.

I checked out your D25A, and it says if you put a Li ion 14500 in there it will be direct drive. Get a windyfire 14500 and you can have your pocket rocket, though without modes.

I did find this this HKJ tested Sibeile IMR16650. Not a big difference in resistance, but is a bit lower.

I've found quite a few different 16650s now that's I've really looked. It's hard to tell what is really under some of the wrappers. Mntelectronics has flat top, button top, and protected (EVVA) Sanyo UR16650ZTA 2500mAh cells, as well as a 2200mAh efest flat top.

There's also Orbtronic 2200mAh cells that are probably Sanyos.

I hope you will share the results. Sounds interesting!

I like the operation of the D25A a bit better since you can start the light in low or high mode, but the modes get screwed when using a 14500. I would love to have a combination of the two, keeping the low and mid modes no matter the battery and only increasing the turbo mode when using a 14500. I think the T10 would be close to perfect if you could start in low and high.

52g 18650 light

That thing is 110mm long - with a side switch!
DQG Tiny is 87 mm, though i have had 2 of them and they both broke


You are wrong the tiny is 97mm long, thats only 13mm less

And the tiny is almost that much thicker than the Skilhunt which kills it

The Skilhunt got a deeper reflector so it is longer but with battery it weights half of the DQG and is a lot more pocketable

Below 100g with battery, removeable tailcap magnet.
Even long protected cells fit in the Skilhunt

87mm long, i had them

“_Waterproof: IPX6; Double O rings in the head.
Size: 87mm(Length)*25mm(head diameter)*22mm(tube diameter)
Weight::38g(not include battery)_”