I'm glad that your battery fit, but tell me, do these batteries look like they fit? I never said that no protected batteries fit; I said that two of the batteries I tried didn't fit and that there's no good reason for the tube not to be longer since there's plenty of spring in the tailcap. Don't put words in my mouth.
Efest @ 53.25mm --- not even close.
EVVA Protected UR14500P @ 52.51mm
My sample is NOT neutral white. I know what neutral white looks like, and this isn't it. Like I said, yours may be different, and it looks like yours and Robo819's copies may have a better LED than mine, but the one I got is a "garbage" tint, so when you buy this light you get to play the tint lottery.
I'm glad that someone is here to keep me honest; remember, this is a review, not a paid advertisement like most "reviews" are. Shill on and keep calm.
I think that “shill on” comment could be seen as being offensive to many reviewers here. Yes, we may received the product for free, but many reviewers including myself have enough honesty and integrity to point out the negatives (or at least use politically careful wording) during a review. Reviewing takes a lot of effort and long time, and even getting a free product is often barely worth the effort.
Incidentally, as you pointed to a product that you do sell, during your review of a product that you don’t sell, then your “shill on” comment is a bit of a case of pot calling the kettle black.
So what we now know is there there is both a tint and length lottery. In other words unlike say Zebralight, Thrunite needs to work on their Production and QC departments adherence to spec (or the spec it self is too loose (see engineering and marketing)).
Let hope they take this fair and honest review and actually find more value in it then we consumers. Meaning if they actually take the time and make the effort to to correct the Tint and Length lottery then their product will be the better for it, and there is hopefully value in that to Thrunite.
Now we have a review that is just short of issuing corrective actions to Thrunite for free, that is a great deal for them. I say if they are smart they will see they received their monies worth.
Funny as I was thinking about a month or two ago how I rarely read about the “tint lottery” these days. In my recollection I used to read about the tint lottery so more often about, what 5 to 8 years ago?
The light has pretty much infinitely variable levels due to the ramping feature. Like I said, the user interface is pretty nice. If you get one with a good emitter you'll be happy with it for a AA light.
Just got mine in Neutral tint. My ~7 year old Zebralight H501 at 80 pure flood lumens was starting to show its age. Still a great light, but its old school XRE Q5 is a bit lacking.
Amazing how technology has advanced. TH20 is impressive, so much light from a single eneloop. I think I got lucky on the tint lotto. My only other light thats neutral (5000K) is an older Fenix LD25. My TH20 tint is very close to that at the 250L setting. Every Cree LED after the XRE I have found to have a pronounced tint shift when under driven. So I am willing to bet when my 14500 cells get here and I can drive the XPL harder, the TH20 will whiten up at the brighter settings.
Anyone have any impressions using Energizer 1.7V lithiums?
I haven't checked this thread since the week I wrote the review after being criticized so heavily for noting that the emitter was green by the schills of the world. I feel at least a little bit vindicated to know that I am not the only one who received a tint-bin-reject emitter.
ThruNite did not complain about the review at all---in fact, they liked it and have asked me to do several since then, but I really don't have time to do them. I just needed to do at least one "sponsored" review to get it out of my system.
------
Anyhow, I would go with the 4000K 219C 90+ CRI at this point---higher flux bin, lower vF.
Apologies for digging up dead discussions, but I am trying to get some clarity on what 14500 cells my TH20 will accept before ordering them.
I found it odd that stephenk reported a 52.7mm long cell fitting when you show a shorter 52.5mm cell protruding from the tube. That didn’t particularly make sense initially, but I may have thought of an explanation.
RMM, were you making your determination of 14500 cells not fitting the TH20 on the basis of the cell protruding from the tube?
That’s a reasonable assumption to make, but I just looked closely at the tail cap of mine to find that there does appear to be a significant amount of recessed space that could accommodate a cell protruding out of the tube. To my eye, it looks like there’s at least 4mm between the bottom of the tail-cap’s threads and the endplate, of which less than 2mm would be taken up by the spring when fully compressed.
Unfortunately I don’t have any cells that protrude from the tube to test it, but the design of my tailcap and tube interface certainly looks like there’s space to accommodate some protrusion.
I’m wondering if maybe you overlooked that aspect of the tailcap and assumed a protruding cell meant it doesn’t fit without trying to seal the tailcap? Or maybe they re-designed the tailcap to accommodate longer 14500 cells and you have an older version?
I believe that there are probably some small variations in the tube + driver overall lengths. Even a few tenths of a millimeter make a difference. It is completely possible that other copies of the same headlamp would fit the same batteries that didn't fit in my light.
The cells did not function in the light. The way that the tailcap and body threads are anodized the tailcap needs to bottom out completely to make a good connection, so it can't be loose and still function correctly.
Shill on and keep calm. 
