Pilotdog tested some 18350 tubes in this thread. EagleEye X2R Mod and Discussion thread
Flat tops should work fine
The charge current is higher than ideal but not so high that is would cause a concern for me. Efest purple 18350 for example has a max charge current listed on their website of 1.4 amps.
Will Panasonic NCR18650B protected batteries work?
Can work but you can feel the tension when tightening.
I use that in my 3 lights and they are fine. Don’t seem tight to me. I use the evva ones that MTN sells.
In both of my lights the springs pops when a protected cell is used, it works but the popping noise is the spring being crushed.
What batteries are you using?
I guess I got it wrong then. After reading this review I thought the flashlight maintains a certain amount of brightness even in high mode, until the low-voltage warning kicks in at 3volt.
After charging the battery I get 0.1A/0.7A/1.6A for the different modes.
I think when you have it running on high, then the light holds high until the LVP kicks in. After this, when you turn the light off, then back on, the high (or even medium if battery is low enough) are kept from coming on. I ran mine down on high and this is what happened to mine. The good thing, hard to run out of light with this X2R!
Glad it is working for you now, and welcome to the forum!
I’m using NCR-B from GB, also tried with EVVA Sanyo GA from MTN, those are shorter and don’t pop the spring, but still a very tight fit.
I’m not sure who adds the protection circuitry and rewraps the GB ncr18650b. Maybe it’s a bit over 70mm?
I’ve got 2 types, the button top evva ncr186650b from MTN and the button top Keeppower ncr186650ga from Illumn. Both measure 69.5mm and both seem to fit fine in my X2R. The softer rear spring fully compresses about 2mm from fully closed and the stiffer front spring then compresses that last 2mm. So it’s snug, but any protected cell will be pretty snug.
I don’t feel the battery itself touching the front, non spring area and being squeezed physically, so I think they are fine to use.
I got my new driver in and it’s working good. I got all 3 modes now.
Send me a PM with your info.
I have an issue with my X2R, the LVP will start at ~3.6-3.8V instead of 3.0V
It’s going to be hard to explain this to gearbest support :person_facepalming:
It’s possible the driver really is getting low voltage. First I would try loosening and retightening both retainer rings. Make sure the end of the springs and battery are clean and then loosen and retighten the body pieces (head tube to battery tube and tailcap to battery tube). Then test it.
What battery are you using? An unusually long cell might be preventing the tail cap from screwing all the way down. My X5R had this issue until I swapped in a better tail spring that could compress a little more.
Thanks for your suggestions.
I checked and both rings (driver and tail) were tight and clean.
All 3 modes (LMH) are good (unlike the problem you had with your X2R)
I used mostly unprotected cells (Samsung ICR18650-22F or 26F, laptop pulls), they work fine with other lights.
Right now I’m testing the runtime on high, with a protected cell. Will report the LVP voltage, but I don’t think it will make a difference.
EDIT : runtime ~52min (starting on high), battery ended at ~3.6V
At last, the light still works (too bad for the extended runtimes!)
If you have to contact the people you bought it from it shouldn’t be too much of a problem if they ask you for a video. I’ve seen videos just like that. They will take a battery and a voltmeter and show that it’s currently like 3.5 volts, they’ll put it in the light, turn it on and it’ll immediately go into low voltage protection and the whole videos is less than a minute and should be pretty good proof of the problem.
You don’t even need to have a YouTube account. You can film it with your phone at a low resolution, in order to keep the file size small, then email it to them.
You are right it shouldn’t be a problem to do that finally 
...and donna is gonna! 
I bought another two X2R… but still haven’t tested the USB charging so i tried it overnight. I then put the cell in my Opus to check and it is 4.24V. A bit high IMO. 4.16V would be safer and would better preserve battery life.
I would suggest trying it again and measuring with a dmm. It shouldn’t be that high.
