Sofirn C8F host. 21700 C8F Available

The future is the mainstream battery, which will replace the application rate of 26650 or 18650, which will be the mainstream of the future market.

Isn’t this just a guessed prediction? Note: I’m not arguing against you, just curious to know if this is just speculation or if manufacturing has actually expressed this. Go to any hardware shop and check for different battery sizes. To me, the variation of sizes appears to have increased over the years. I wonder why people are so sure that that is going to change.

So make 26650 today and 21700 in the future :stuck_out_tongue:

If Samsung took the chemical mix of their 48G and put it in a 26650, we would have a 10A-12A constant output with maybe 6500-6800mah.

Unfortunately, we currently only have 20A 5500mah 26650’s at the moment.

Are we assuming that Sofirn might sell a 21700 version as a complete light with a battery or would it only be as a host?

I notice they offer their 26650 light, the SP33, with an optional battery, but it’s an 18650 cell and not a 26650.

One thing I notice about the other three lights on/near the market using the 21700 is that all three of them have built-in recharging. I’m pretty sure Sofirn is not going to redesign their driver to add built-in charging to it which could put a certain amount of buyers off of that size simply because their current battery chargers won’t accept a cell that long. It’s something to think about.

I think it can be built with built-in charger or attached seat, SOFIRN is willing to listen to our voice; I will contact them to arrange this proposal and send it to SOFIRN.

There are only a handful of good Lithium type cell manufacturers. Some of them are already changing there production to the new 21700 (/ 20700, not sure what’s up with that size).
The 26650 size is, afaik, not being produced anymore by the major manufacturers. Only some smaller and Chinese manufacturers might be producing them, same with the smaller less used sizes like 18350 and 26350.

The 21700 size is superior to the 18650 on efficiency. It has more capacity / power for it size (higher power density)

I don’t think that the 21700 can surpass the capacity of the highest capacity 26650’s. Mostly because they are just a lot bigger. However the 21700 will have (possible already has) a higher power density than the 26650 and thus you could conclude that it has surpassed the 26650 size.

Don’t forget that the size is only 1 part of a cell the chemistry is also important and can result in huge improvements.

They already know we need a charger and battery. They will stock them when the flashlight is on sale. They will not put built in charger in this.

Jason: they will sell both complete flash light and host too. As the 18650 C8F.

I see. If that is so, then yeah, anything new that isn’t 26650 is the future.

Aaaw. Just because an influential m0r0n called Felon Tusk decided to bring to market a new cell format…

I do not know what are the “official” reasons behind such new cell format but, beyond any whatever claimings (volume to surface ratio increase and etc), it is obvious they didn't choose 26650 to avoid providing head start to any current industry infraestructure. Packed in honeycomb arrangement there's no actual difference in the space occupied by cells in cylindrical formats.

Since the 21700 format has been brought for the new and soon largest by a long shot market of electric vehicles and such, it was quite logical for all the major players in this industry to follow. No big deal to understand, doesn't it?

21700 better than what? Sorry? 21700 is ∅21×70mm, just that. Now, if the thing behind this (cough!) “breakthrough” were to disappear, no one would @#$%ing care about it.

Lots of useless chit-chat in this respect, imho.

Cheers ^:)

Except that the chinese manufacturers are catching up the major ones in capacity and current handling (not sure about safety), my Keeppower 26650 6000mAh (I measured 5800) is not that far behind in specs anymore.

Barkuti, name calling is just rude and uncalled for. So you don’t care for all the good things Musk is doing, no need to act it out in this forum.

The 21700 cell is making some surprising impacts, namely I’ve seen a pair of the iJoy 21700 deliver 32A at the tail to 3 XHP-70.2 emitters for right at 19,000 lumens… no other cell that I’ve tried comes close and I’ve tried more than a few of the top choices.

So if the 26650 cell were designed for, but room was allowed for the length of the 21700, it’d be easy enough to accommodate both cell sizes and no re-design would be needed down the line.

Are you sure about this?

I looked for 2 fairly new cells with the same continous discharge rates in order to make it as comparable as possible. Apples to apples, so to speak.

Samsung 48G - 4800mah 10A
This 2170 cell (this is the new size Tesla is calling it) has a volume of 24.25mm3.
This equates to 198mah/mm3

LG MJ1 - 3400mah 10A
This 18650 cell has a volume of 16.54mm3.
This equates to 205mah/mm3

So they are pretty much the same - power density wise. The 2170 is about 47% bigger and has about 41% higher capacify. It’s not an exact scale up, but almost.

It seems Tesla is predicting their new 2170 will have a capacity of 5700-6000mah!. I have not seen any batteries with that much capacity. Not yet, at least. Have any of you?

If this turns out to be true, then the power density will definetly exceed the 18650.

So far, I really like this quote from John Peterson.

“Batteries are chemistry in a can and changing the size of the can does not change the energy density or cost of the chemistry inside the can.”

-Ps, the 20700 was going to be Tesla’s new battery size for 2017, but they changed their mind to the 2170. This is what I see reported, I’m no Tesla expert, obviously. Lol

Betting in the 21700 is just that, betting.

The chemistry might be the same, but the efficiency of how much of that chemistry you can safely stash inside the can tends to go up as more R&D is put into the cell and specially in to the cell manufacturing machinery, so that is why my bet is on the 21700 format for higher energy density in the coming years. It might stay the same density, in which case I’d still prefer the 21700 over the 26650 because of the versatility of the size, my preferences on the design of the flashlights and the availability of cells from reputable manufacturers

I definitively think different, but just wanted to lay out a joke with Felon Tusk, too good to pass imho. You know, :-D Tusk ≠ Musk.


We'll see if that turns out into real non-overstated figures, and how much of it will be left after 2K cycles.

Cheers ^:)

TrustFire 32650’s have 6000mAh capacity, and then a bit. They do pretty darn good in power delivery as well. I have 5 of them I think, 3 in one light… the TRJ20.

The problem, how I see it, is like Barkuti says… how many cycles are these chemistries going to last? Pretty darn expensive to have to buy a new “engine” every 4 or 5 years.

I think for this iJoy 40A 3750mAh 21700 cell, they probably use a similar chemical mix to the Sony VTC6 or similar battery. High amperage at the expense of capacity. (Mooch says this cells continous discharge rate is far below 40A, it’s about 24A)

Just general info for everyone:
Battery manufacturers can tweak their recipes to give more capacity such as the Samsung 48G (4800mah 10A) or more amperage like the Samsung 30T (3000mah 35A - which actually does 40A continous! Along with 10-12 milliohm internal resistance!)

It’s also important to note that the best chemical mixtures, the ones with the best efficiency, are the ones by the Big 4. Samsung, Sony, LG and Panasonic/Sanyo. (I hope I got this right). All the other battery manufacturers have “lesser” efficiency. Unfortunately none of the Big 4 make a 26650. That is why they lag behind the 18650 in efficiency and are almost caught up by the 20700 and 21700 which ARE being made by the Big 4.

Can you imagine a Samsung 26650 (which has a volume about double the 18650 at 34.5mm3) with the same chemical mix as the 35E? It’s capacity would be 7000mah and maybe have a 16A continous discharge rate. Compare that to the current KeepPower 26650 with 6000mah and 10A cdr.

Or Samsung could do a 26650 version of the high amperage 30Q. 6000mah and maybe 30A-40A cdr. Compare that to the current Liitokala 5000mah 20A battery.

26650’s would be serious contenders if made by the Big 4.

True, I should have stated ‘is going to be’.

The problem with 18650’s is that they maxed out.
So in order to improve battery performance they needed to go bigger. And, yes Barkuti, the 2170(0) size is more efficient, given the (possible) improvements on the capacity and performance, in the space they have to build battery packs. So that’s the reason why they went with the 2170 size.

JasonWW, I thought Samsung came up with the 20700 cell before tesla came up with the 2170?

But this is going a bit offtopic :smiley:

Well the 20700 was definitely before the 2170. Did Samsung make a 20700 before Tesla did? Idk. If they fid, why? What was it meant to be used for?

We always go off topic. Lol. At least this time we all seem to be learning things.

BTW, my Miboxer C4-12 can take a 72mm cell and my Xtar SV2 Rocket and Xtar VC4 can both take a 71mm cell. These unprotected 21700 look to vary between 70mm and 70.5mm. I am good to go! Lol

I voted for 26650 earlier, but now I think I will vote that both new sizes are okay by me. :+1:

Measured my chargers:
Opus BT-C100: 72,7mm
Zanflare C4: 70mm
Liitokala Lii-500: 70,7mm
Liitokala Lii100: 70,6mm

Jason, my wife is gonna moidarize me and it’s your fault! I ordered 2 of the Samsung 30T’s to try in my triple 70.2, see how they fare against the iJ0Y’s. These are not cheap cells!