For 20700 cells you’d need to increase the inner diameter 5mm and 21700 would need 7mm. I don’t think there is any way they could do this without redesigning the lower head plus making a new battery tube, carriers and tail cap. I don’t see them doing this.
Thanks…
Maybe I would like to use LiPos instead of 18650er LiIons.
I´ve ordered a short tube, and a colleague has drilled me some coupler.
He will drill me also a coupler/extension which I can screw between short tube and original (long) tube.
So I will get a 300mm Tube…
Maybe he can drill a new tube for me and some adapter…
Original has about 46mm inner diameter.
New should have +7 = 53mm. With an 55x5Tube it should work… only flight of fancy… ;).
This light will remain 18650 but there is another light in the works that I have been debating between 21mm and 18mm cells.
My biggest worry is that the 21mm cells will make the battery tube too thick for some to easily grip. I have large hands and find the current GT grip comfortable but much larger and it would quickly become hard to hold for any length of time.
I figure those with smaller hands could already be at the point of hard to hold as is.
Maybe with the next one they can make a factory handle which is removable easily with one screw if don’t need.
Or put in a fan as Acebeam 
(Sorry…Just kidding 
)
Putting an Acebeam type fan would not be a bad idea. It should be relatively cheap to make and gives us an affordable option for active cooling. I wouldn’t mind 4x20700 or 8x20700 cells. People seem to be ok with the Imalent MS12 and R90C.
Next blf gt should be in 4 x 20700 and 8 x 20700 tubes., skv is right.
Then jump right to 21700. You can fit 20700 if you have that but you can’t fit a 21700 to a 20700 space. Either way it is too thick to hold the tube in hand so why not?
I’m with TA, the battery tube is big enough with 4 x 18650. I have big hands too & bigger is just not practical IMO.
BUT, if the powers that be decide to make the jump…… no sense in jumping halfway. Jump all the way and go with 21700. Might as well… both 20700 & 21700 are to big, so might as well go all out so the carriers could hold either one.
I cant even hold it with my hands really, i use the strap, so 21700 would be fine…also its so heavy…i dont knoe who could hold it for a long time.
I will keep all of these comments in mind on the 21700, I am smack in the middle and don’t know what to do about the cells on this future light. I can see both sides.
Also, I might not be around for awhile due to a lightning strike on the ATT hub for the whole north Texas area:
I will try to catch up when my internet is restored.
Bigger relector would be sweet.
What is the energy density of current cell formats? Which one gives the best ratio of energy stored considering its volume? We could always go bigger than 21700, it is already too big for normal use. Why not 26650 or even 32650 cells?
If it needs a lot of power it need to go big and some 21700 has unbeatable high drain current now.
26650 and 32650 are much less energy density because no big manufacturers making them like LG or samsung……ETC. But 21700 is pushing hard now.
Best 20700 is the Sanyo 20700B at 4000mah and 15A, while the best 21700 is the Sanyo 21700 5000mah 15A. Not sure what density that equates to.
But for a very high power flashlight it more important how big current a battery can put out continuously, than how big capacity it has. If it only has 4000 mAh but can push 40A current I’m more happy
The best versions (made by the big companies) of the 18650, 20700 and 21700 all have the same energy density (within a few percent) because it is only the container size that is changing.
32650 are very low in density as not many companies devote time to them.
The 26650 is a bit different. None of the big companies make this size, but the energy density seems to vary depending on the chemical mix. If your looking for high drain/low capacity, there are versions that are comparible to 18650, 20700 and 21700. You would need to look at the Golisi 4300, iJoy 4200, Shockli 4300, etc…
When it comes to high capacity/low drain, the 26650 has not been able to match the smaller sized cells made by the big campanies. The closest is the PLB battery sold as the Shockli 5500 and KeepPower 6000.
Here is a handy list of battery configurations and the inner diameter needed to fit them.
4 x 18650 = 44mm
3 x 21700 = 46mm
4 x 20700 = 49mm
5 x 18650 = 49mm
4 x 21700 = 51mm
3 x 26650 = 57mm
Container sizes (roughly):
1 x 26650 = 2 x 18650
1 x 21700 = 1.5 x 18650
I am watching the 21700 discussion closely. A strap would be required if that change was made to the new light.
Also, a quick recap on the KD XHP70.2 80CRI LED’s from a page ago. With my internet being down I went ahead and put together my MT09R with those LED’s and I am very impressed. The tint is great and output is good as well.
Compared side by side with the 80CRI LED’s I have been using the lumens are around 10% lower it seems (most likely they do not have the same silly low vF).
The tint if anything is a little better then the LED’s I have been using, very minor difference and most likely would not notice it unless you had them side by side but the KD LED is a little rosier.
Overall I would run either of them without a problem, the choice os slightly more lumens or slightly rosier tint is not enough for me to worry about.
1 month of someone else holding $55 of mine. What’s another month? :weary:
Sorry about that delay, they did not expect the delay with the NW emitters and they had planned to get everything finished before the week long holiday.
The emitter delay threw a wrench in everything and they are just now getting caught up.
Had I know this I would of told them to not list the conversion kits until now but retrospect is 20/20.