18650 / 21700 / 26650 ... what size of Li-Ion Batt to "keep"?

yellow

Flashlight Enthusiast
Joined
Oct 31, 2002
Messages
4,622
Location
Baden.at
Hi.
1st off, I am totally into 1*18650,
and like the lights' size format the most.
+ think to be better off with an additional spare cell in regard to a bigger light with larger cell
+ the larger cells I had so far - 26500 and 26650 - simply were on the lowest end of quality.
.
So, question:
for that one additional "bigger" light,
for "thinking into the future"
what cell might be best to plan?
21700
26650
32650
even a different one to these 3 ?
 

Guitar Guy

Enlightened
Joined
Oct 23, 2016
Messages
580
Location
West Virginia
The 21700 seems to be pretty popular, and a wide variety of lights are available these days that use them. I have several that run on a single 5000 mAh 21700 and like them. They seem to perform well.

I do like my 18650 lights very well, also. To me, an 18650 light that is small enough and light enough to clip onto the bill of my ball cap is a very useful piece of gear.
 

Monocrom

Flashaholic
Joined
Aug 27, 2006
Messages
19,540
Location
NYC
21700 definitely. That's going to be your best bet going into the foreseeable future. Already a surprising number of popular flashlight models designed around the 21700 battery.
 

Monocrom

Flashaholic
Joined
Aug 27, 2006
Messages
19,540
Location
NYC
I'd say 21700. I have a **it ton of 18650, but I've always preferred a "C" size for feel in the hand. A 26650 would be even better, but progress seemed to stop on them and 21700 is the cell now. Even 18650 sized lights I do not feel are really pocket/edc friendly, so might as well go bigger
Just the other day, my Convoy S2+ arrived. Single-18650 light. About as thick as my old incandescent SureFire E2E. And, about as long too. Have an aftermarket clip coming for the S2+. Sure, it's pushing the upper limits of an EDC light. But not excessively so.
 

vicv

Flashlight Enthusiast
Joined
Mar 22, 2013
Messages
2,730
Location
Southern Ontario
Just the other day, my Convoy S2+ arrived. Single-18650 light. About as thick as my old incandescent SureFire E2E. And, about as long too. Have an aftermarket clip coming for the S2+. Sure, it's pushing the upper limits of an EDC light. But not excessively so.
Ya I enjoy mine. Not sure id agree it's as slim as an e2e though. I've never carried an E2E, but I do have an A2. And it fits in the pocket better than the convoy. But you're right it is very close. Especially with the small diameter head.
 

Poppy

Flashaholic
Joined
Dec 20, 2012
Messages
8,311
Location
Northern New Jersey
It's amazing what the difference a couple of mm can do regarding the EDC carrying ability of a light. In the picture below I present a 14500 Eagtac D25A on the left, a 16650 Thrunite 2C, and a 18650 Convoy S2+.
Unfortunately I don't have a 21700 light.
The 14500 is MUCH more pocketable followed by the 16650. By time you get to the 18650, it is more a pouch/holster carry or coat pocket carry. I imagine that 21700 lights are only holster, or coat pocket carry lights.

1699623439188.png


While I don't have any 21700 lights, I *think* the answer to your question is the 21700 battery. I think, due to its higher capacity, it is the battery of the future.

When we review any thread that asks what is your EDC, I believe that for the majority, the answer is the smaller the better. Many carry keychain lights, in the AAA format in their pocket, otherwise it is 18650 lights in a backpack or briefcase.
 

vicv

Flashlight Enthusiast
Joined
Mar 22, 2013
Messages
2,730
Location
Southern Ontario
It's amazing what the difference a couple of mm can do regarding the EDC carrying ability of a light. In the picture below I present a 14500 Eagtac D25A on the left, a 16650 Thrunite 2C, and a 18650 Convoy S2+.
Unfortunately I don't have a 21700 light.
The 14500 is MUCH more pocketable followed by the 16650. By time you get to the 18650, it is more a pouch/holster carry or coat pocket carry. I imagine that 21700 lights are only holster, or coat pocket carry lights.

View attachment 52129

While I don't have any 21700 lights, I *think* the answer to your question is the 21700 battery. I think, due to its higher capacity, it is the battery of the future.

When we review any thread that asks what is your EDC, I believe that for the majority, the answer is the smaller the better. Many carry keychain lights, in the AAA format in their pocket, otherwise it is 18650 lights in a backpack or briefcase.
Where did you get the screw on pocket clip? The one I got just sits on the body of the light. It pops off easy and adds a lot of bulk. Not to mention what it did to my anodizing
 

Jean-Luc Descarte

Enlightened
Joined
Jul 29, 2020
Messages
788
Location
Where the sun sets fast
21700, definitely. It has plenty of power in a compact size, surpassing most 26650s, and has already established a spot for itself in the market - it'd be a relevant format even if Tesla dropped it entirely in favor of another form factor.

Nowadays, getting new 18650 torches for me instead of 21700 would only for the smaller dimensions, weight included, and maybe costs. I flip-flop between my 18650s and my 21700s more for emitter preference than anything.
It's amazing what the difference a couple of mm can do regarding the EDC carrying ability of a light. In the picture below I present a 14500 Eagtac D25A on the left, a 16650 Thrunite 2C, and a 18650 Convoy S2+.
Unfortunately I don't have a 21700 light.
The 14500 is MUCH more pocketable followed by the 16650. By time you get to the 18650, it is more a pouch/holster carry or coat pocket carry. I imagine that 21700 lights are only holster, or coat pocket carry lights.
Here's two instances of the S2+ alongside the S21A, basically an S2+ upscaled to 21700 size.
16997396416174970542637979411368.jpg

The S21A is not that much bigger, definitely still pocketable (for me they both fit snugly inside the jeans' coin pocket), although with both lights loaded with batteries, the S21A weighs a full ounce (30g) more. Certainly enough weight to be felt if you're not a big guy.
 

vicv

Flashlight Enthusiast
Joined
Mar 22, 2013
Messages
2,730
Location
Southern Ontario
I don't seem to have the obsession with runtimes that others too. Most of my 18650s are under 2000mah. And they last me a long time. And I prefer incans. So going up to 21700 doesn't have an upside for me
 

Jean-Luc Descarte

Enlightened
Joined
Jul 29, 2020
Messages
788
Location
Where the sun sets fast
I don't seem to have the obsession with runtimes that others too. Most of my 18650s are under 2000mah. And they last me a long time. And I prefer incans. So going up to 21700 doesn't have an upside for me
Interesting how people have different priorities. Me, I put runtimes far beyond brightness or even beam quality if necessary. The secure feel of having light for a long time was what sold me on 18650 as far back as 2014, and I still can't have enough. I rarely need to recharge a flashlight more than once a month and I love it that way.
 

Monocrom

Flashaholic
Joined
Aug 27, 2006
Messages
19,540
Location
NYC
I'll still buy an 18650 light, but it has to be fully compatible with 2xCR123 primaries for emergency use. As much as I love my 21700 lights, the lack of lithium primary dual-fuel compatibility is the biggest disadvantage for me.
 

vicv

Flashlight Enthusiast
Joined
Mar 22, 2013
Messages
2,730
Location
Southern Ontario
Interesting how people have different priorities. Me, I put runtimes far beyond brightness or even beam quality if necessary. The secure feel of having light for a long time was what sold me on 18650 as far back as 2014, and I still can't have enough. I rarely need to recharge a flashlight more than once a month and I love it that way.
Ya I like we have different priorities. I do wonder how much runtime a person really needs though. I have a convoy s2+. I don't use it very much because it's just about the perfect light. It's throwy with the small sst-20 and smo reflector, but the reflector is small so not a thrower either and plenty of spill. It's small. It look pretty good. But if I use it much, it makes me wonder why I'd need any other light. Hence why I don't use it much. But I digress. I have it setup with 5 modes. .1%, 1%, 10%, 30%, and 100%. High is 1.4a so should be roughly 450 lumens with the 4k emitter. My most used mode is the 10% which is about 40-50 lumens.
Even with a 2000mah battery, that's like 14h of runtime. If I had a newer 3500 mah cell, it would be more like 25h.
How much more runtime does one need?
 

Monocrom

Flashaholic
Joined
Aug 27, 2006
Messages
19,540
Location
NYC
Just want to say, very recently got my Convoy S2+ in the mail.
Already love it. Looks like a very simple, unassuming light.
But it just might be ideal for a non-tactical flashlight as an EDC.
Still waiting on the aftermarket wrap-around clip to arrive.
Though, I doubt the wrap-around portion will hold up. Too thin.
Thankfully found an ETSY seller who has a different type of clip for it.
Plus, ETSY has turned into a bit less of a site that caters to scumbag con-men sellers during the past year. So likely worth it.
 
Top