Both 26650 and 21700 are welcome 18650 is too short runtime for this Amp.
I think a 26650 model would be a very nice addition.
+1 for 26650. But the C8 design will be a bit strange with that. O think if the make a completely new design it will be better than a fat C8. I suggested to them to make a triple from SP33 but not heard anything from that.
Why only triple? 
Make it 5 XP-L for 26650!
With a triple it can handle the heat for about 2-3 minutes. With 5 it will be uncomfortably hot after 10-20 seconds. And you only gain about 1500-2000 extra lumens for tgis short amount of time. I will go for 3-4000 lumens for minutes instead of 6-7000 for seconds.
A C8 with 26650 is a very nice size. It fits the hand well.
Here is Supfires new C8-X. It has the same 45mm head diameter as a C8.
It’s not a triple xpl, but it gives you an idea of the preportions.
I would like one myself, but only if it also had a tail switch. I prefer dual switch lights.
Jason I not mean the head diameter avout C8. I mean the head side design will look odd with a bigger tube this Supfire looks good.
I’m in between 21700 and 26650. The verdict: I’d be happy with 26650 but even happier with 21700. Please redesign the head to get rid of the typical C8 cutouts and add more fins.
I still like the venerable F13. It feels good, is nicely balanced, has quite good throw, is nice and “finny” for good heat dissipation, and while the usual come-with driver/UI and emitter are generally crap, it mods very well into a good solid kick-ass light.
If Sofirn would put their stank on it, it should be a really nice F13 reboot.
1 for the 26650. I’d buy me a few of them hosts in no time.+ for a quad design but that’s not what they are asking.
Either 26650 or 21700 would be welcome.
+1 for the 26650
count me in 
That c8-x looks like a sausage. See my thread on the EC21 to see what a 21700 tube looks like. Its not quite c8 diameter but super close
I’m not into lights with mechanical switches like C8, but I’d like to comment nevertheless…
- I’m very impressed with what Sofirn does to their C8 line. This discussion adds to that.
- What cell would be better for this light?
- 21700 will feel in the hand just as good as 26650. It will feel better in the mouth. Not that it’s the way most use their C8 lights…
- 21700 will weigh significantly less
- The capacity advantage of 26650 is about 20%. Though the highest capacity 26650 cell offers smaller IR than the highest capacity 21700 on the market. It is expected that 21700 will progress faster than 26650, so the advantage of the larger format is more likely to shrink than to grow.
- There are cheap and OK 26650 cells available. 21700s tend to cost more.
- At the moment it seems that 26650 are supported by more chargers, though I wouldn’t be surprised to see that to reverse in the coming years.
To me it hints that both choices are good, but personally I’m more into 21700 lights.
I’m a little confused, are you talking about the older, regular C8 designs that only used a mechanical tail switch?
This thread is mainly about the Sofirn version which has no mechanical tail switch, it only has the side mounted e-switch.
I’m talking about both.
In dual switch lights, I find mechanical switch to serve no purpose other than that of mechanical lockout. I consider them way too bulky for the value they provide.
I would like to see a 26650 version.
Please make sure the Liitokala 26650 will fit as they are some of the larger diameter cells.
Ain’t THAT the truth! No easy modding with this light, can’t just pop off the MCPCB.
I have six C8F hosts with two built so far. They take time and are not an easy build like my C8(s) host (also from Sofirn) which was a breeze to build in comparison.
The C8F builds are THICK and heavy in the head when compared to other C8s. So I’d like to also see more internal milling in the head area to lighten it up (and make room for the LED wires to get through to the MCPCB side without my having to re-drill them from the driver side myself). Then a larger battery tube for a 21700 or 26650 sounds like a GREAT IDEA. :+1: Maybe even go to a 20-21mm driver while they are at it? (like they DID as an option for the C8(s) host they make).
I am finding shaved leds (or XLP HIs) are the best fit for my C8Fs and I wonder why there are not standard in the factory made C8F. With standard XP-L2s (V5s), this light is VERY bright but doesn’t throw as good as it can (I’m using Lexel’s TA NarsilD driver, BTW). My C8A (factory build by Sorfirn) using the same XP-L2 led out-throws my first C8F build (with three of these same leds in it). So the triple reflector being cool and all, still can’t get much throw without using an LED made for the job.
Shaving my XP-L2s helped on my second build and now the throw is better… BUT I am looking forward to finalizing my XPL-HI build in a few weeks— THEN I’ll know. So I might have to go back to my first build and shave the stock XP-L2s down now— again painful (so I may just gift it instead).
Anyway, the C8F IS a great light… ONCE it’s built 
And there is some potential for a larger battery version with tweaks too.
I just sent a message to Sofirn about this conversation
Highlighted the most important things. If 26650 chosen fit Liitokalas. I sent the size of my black liitokala 26650-s. More fins on head, 17 or 20mm driver diameter because those are common.
Stay with switch on separate pcb.
Start sale with complete light and also as a host.
/\ . :+1: