I don’t worry about it personally, the springs are stiff enough to handle a fair amount of variance. I only use un-protected personally, the chances of having an issues with 2 unprotected cells that are even reasonably matched, in a single discharge cycle is virtually nill.
Any mismatch is balanced out as soon as you recharge them. Mismatched cells are a larger issue in things where they are never removed from the series.
+1
+2
Good, I thought I had missed something or was “loosing it”. 
I only have two 26650 Liitokalas but they fit perfectly snugly inside the L7. No way they can be used in series without a magnet or the Convoy connector though. True flat tops. They are just a bit fatter than the 4500 mAh protected Keeppowers, 26.64 vs. 26.53 mm at their widest part.
What is the “Convoy connector” ??
Where do you get it?
OK, no problem…… 
I was just curious about it.
Hi all,
Just got my L6 and I love it.
I’ve had some other Convoy light before (first edition L2, M2) but the build quality on the L6 is even better.
Indeed very impressive for a light in this price class.
I’m going to use the new 2016 style Efest IMR4200 cells, because:
Cheers
Nico
Have you used these newer Efest batteries and did they work?
The liito kalas are true flat tops instead of a magnet I took a small knife on all 4 of them and slightly bent up under each of the four prongs on the top and now work perfectly in series. In the l6, s70 and prototype hd2010
Your a braver man than I Speed4goal, but glad it worked for you. :+1: …
bella-headlight, (and maybe some others ??); has posted that he has several and all of his work in series.
While I have several and none of mine work in series. They are close but no cigar……… 
Oh well………
Nope, I have no experience with them but seing the tests of the various newest Efest 18650 cells and tghe performance of the older model 26650 Efest cells I’m goign to take the risk.
Might do it thruy one of the German cell testers on “Taschenlampenforum”.
Grtz
Nico
I have a 3x set of purple Efest 4200mAh cells that I acquired 4 months ago. They work just fine in series.
I will check their fitment in an L6, but I will be using a dedicated pair of liito cells for actual use. Gotta wait for it to get here though.
+1
Let us know if they worked out; the Efest is a well regarded battery.
+1
These EFEST IMR 26650 4200MAH fit my L6 fine-
The liionwholesale pictures are the older 4200's, the wrapper is now metallic, and they are 35A continuous, 50A pulse, not 40/60-
Lol well I figured If I’m holding the cell the knife is only touching to positive prong with nothing to ground on to make a short. They barely don’t touch stock. Just barely bending the prongs make them touch and work perfectly. And no magnets increasing resistance or anything a small screw driver would probably work as well
Oh I know, I was just fooling with ya’.
I am probably gonna give your method a try myself, because you are correct; they are extremely close to touching!
In fact if I lay a couple of mine on the table in series and push them together real hard they will connect, according to the DMM anyway. But they won’t work together in a light…. and it has real strong springs also.
A few thousandth’s taller and they would series just fine. :person_facepalming: Oh well………
I do not like magnets and will not use them in fact. I’ll use a Jaxman Series Connector or a solder blob as a last resort.
I have the original L6 and the end I have to adjust the ring to make sure the cap stays snug. However this small adjust always throws off the light from working. It’s really sensitive, I have to get the right distance. Is this normal for the L6?
Here is the pic? I constantly have to readjust to make the light turn on. Is this normal?