The latest batch of batteries I got from BIC appeared to be really bad. Blue Ultrafires rated at 2400 mAh were 220 in real. And 3600 protected UFs only 880 mAh. I'm not buying another battery from BIC. I guess FocalPrice green Panasonics are genuine but maybe with untuned circuits.
There isn't any cell manufacturer as far as I know selling protected cells, they are always unprotected, they are protected by the companies who re-label.
The first batch I had from them (talking about 2400 ones) were way better. They now sell uberly inexpensive but apperantly junk cells under UF brand. I have always avoided UF cells but were surprised I had good luck before.
FocalPrice has really good prices if bought over 3 pieces. I really wonder how my ones will measure. As the OP says, they will more likely be genuine. Maybe I'll get their 2900mA Panasonics too.
I feel they are genuine just from the measurements given by ada_potato if we take as a true value the 3100mAh of the panasonic, compared to his trustfire flames gives us the trustfire flames are 2254mAh which sounds to be true on the old batches of them.
I have just seen this same panasonics at CNQG, the price is a lot more expensive, but at least they have published its resistance, being ≤45mΩ.
They published something that is absurd, they cannot be under 100mOhm. The cell alone has 80-90mOhm and "standard" mosfets will add 25-38mOhm, from 4.5V to 2.5V
Flashlights are only a realy small niche for li-ion batteries. Most of them are build for laptops and nowadays for e-bikes. They need unprotected and Panasonic, Sanyo, Sony, LG etc. built them.
AW, Redilast, Xtar and other brands build a protection and wrapped.
I think the Focal, BIC Sanyo and Panasonic batteries are genuine (the MarsFire have only the wrong mAh in the titel and the description). Manafont sell them, too (they do not name mAh):
Here is the 2A discharge curve for the first cell:
The charger monitor programm unfortunately crashed while discharging the second cell. So there is just a picture of the charger display. I twas discharged with 2A too:
The cells did match pretty good. But I think you have to discharge them down to 2,5V to get better mAh results.
I expected the difference of roughly 500mAh to be the result of not discharging them to 2.8v but to 3v.
But it might be a combination of the charger not charging them to 100% and showing a little to low results in discharging. So take the above discharge with a grain of salt.
I will get a better charger and we'll see. You can't do anything wrong with an iCharger 206B, right?