I found an online store that has the Nitecore UI2 charger, and asked them to measure the slot length, this is the picture they sent me:
I measured the QB26800 battery to be around 80.8mm in length, so it would seem it’s a very tight fit (but can probably fit).
Nitecore UI2 charger arrived about an hour ago. I’m charging a pair of 26800’s that I ran down to 3.25v last night. They fit perfectly as Hamburglar had discovered earlier. Currently charging at 1000 mah each. Nitecore on their website listed 800 and 1000 mah per cell. Both batteries fit with about a 2mm gap between the cells and about no gap with overall length. Both the Nitecore UI2 and UI1 can be added to the short light of chargers. Easy to insert, only slight care when removing.
I'm really liking the T42's. The T50's are good too. I'm trying to buy a batch of the T42's off of a wholesaler on Alibaba - I'll see how it goes.
I've been finding the T42's are as good or better than 40T's as far as amps, little more capacity.
Wow nice! What brand are those? 21700 right?
After seeing the post from Texas Shooter about Nitecore UI2, I tried charging an 26800 cell with my Nitecore UMS4. A very tight fit, but it is charging. 
Hmm. I tried the 26800 on the earlier UM4, and 26800 won’t fit (it’s lacking a tiny bit).
HKJ’s review indicates the UM4 has slot length up to 79.8mm
HKJ’s review on the UMS4 states slot length up to 77.8mm.
If 26800 will fit the UMS4, that means HKJ’s review may have an error on the slot length?
(I measure 26800 battery to be around 80.8-81.0mm length)
d_t_a, You should try charging on UMS4. I did it yesterday and it worked. Pushing in the positive side first and squeezing in the bottom. Very tight but it is OK.
The 26800 cell came from Shenzhen Cozemate Electrics Store on Ali Express. In fact I am going to buy two more from this seller. After 4:00 p.m. today, the “sale” will start and the price for two cells comes down to S$32.80 (about US$24.50), with free shipping and no tax.
Nitecore UI1 is ok for 26800
UMS2 ok too , more tight but usable
UI1
with margin
UMS2
No margin, need put inside like that
keep the edge of the battery as close as possible and then adjust when the top is passing
no need to force, his pass just but his pass.
It’s the cell from Nealgadgets with NSX4E
I measure it tomorrow
Is the Nitecore UI2 the best seperate charging solution currently available for 26800 batteries?
Probably, along with the Olight UC magnetic USB charger, Nitecore UI1, Nitecore UMS2 and Nitecore UMS4. This is our short list so far as usable chargers go. The Nitecore UI2 and the Olight UC magnetic USB charger are the two I’m personally using both are slow charging taking up to 12 hours on a fully depleted cell. Both also stop at 4.19-4.20 volts every time.
Thank you, I’m happy to buy the UI2 over any other models but is it difficult to put a 26800 battery in or remove it? If it’s any more difficult that putting in a 18650 I’ll probably just buy the LC10 instead. I don’t want to damage the battery getting it in or out of the charger.
You just need to be careful that it’s at it’s max under some tension. A careless pulling out of the cells could nick or tear some of the batteries covering. I pull the positive side up first and ease the cell out, no issues.
Apparently, I’ve discovered that there are different 26800 batteries — slight differences in length, which can affect how they fit in the Nitecore UMS4.
a) for instance, I got a 26800 battery (included with a flashlight) from Neal’s, this 26800 battery is just labeled “26800 6800mAh 3.7v” on the wrapper, and wrapper is sort of blue-green color. I measured its length to be 80.3mm, which fits in the Nitecore UMS4 slot (it’s tight, but doing carefully should not tear the wrapper).
b) I ordered a Pioneman K80 flashlight which came with a (sort of “used” 26800 battery - it has solder marks at the bottom of the battery), this 26800 battery measures 80.9mm in length.
This 26800 battery is in a blue wrapper with no label at all. Wasn’t able to fit in the UMS4 (I got the “GSE26800-68NP” first, which I managed to fit with difficulty)
c) I got an Astrolux FT03 with 26800 tube & 26800 battery. The battery is labeled GSE26800-68NP, and wrapper is light green color. I measured its length to be 81.0mm. I had a very difficult time trying to fit it in the Nitecore UMS4 ( the battery sort of fit but with a very slight dent on the battery). I did not try to fit it again in the UMS4 charger as it may dent/damage the battery.
d) QB26800 (QueenBattery), wrapper color is sort of “ochre/beige”. I measured the battery length to be 81.3mm. This battery simply won’t fit in the Nitecore UMS4 charger.
I suppose there may be more types of 26800 batteries, but it looks like (from my 4 different 26800 batteries, sourced from different suppliers), the 26800 battery length can range from 80.3mm to 81.3mm length.
I only have two of the batteries listed above. C) GSE26800-68NP, and wrapper is light green color. D) QB26800 (QueenBattery), wrapper color is sort of “ocher/beige”. Using my best dial caliper I got 3.185” 80.9mm’s on light green’s or C style and 3.195” 81.15mm’s on ocher/beige QB26800 (QueenBattery). Both of these batteries fit the Nitecore UI2 that I have.
So I’ll change my recommendations to what charger works best as only Olight UC magnetic USB charger. Others may or may not work. Sorry for any confusion.
I want a 26800 tube for my d4v2
If the Nitecore UMS4 can fit 26800, can the Nitecore UM2? the Nitecore UM2 seems a better choice over the Nitecore UI2
I personally have neither. I only have the Nitecore UI2. Seems some are having total length issues with cells and chargers. All except the Olight UC magnetic USB charger are tight fits.
In the event that you might want or really need to remove a cell quickly/immediately from the charger, can you do that when cramming a 26800 into these units where it’s a game of angles? If we’re needing to be extra cautious not to tear the wrap when inserting and removing, that’s already a bit too tight. Maybe best to stick with onboard, diy connections, or the Olight/Folomov until a more compatible bay charger shows up. I hope Xtar comes through this year.
Thought I’d let you know we finally got our restock of these cells in. They went really fast last time around, and since you were the first group to discuss them, I thought I’d give you first crack at this shipment. Sorry, it has been a number of months since we had any. Last shipment sold out in less than a day.
Sorry, forgot the link: