I am a noob, so anything I say you can figure is only half accurate. I just started the venture down the path of lithium ion batteries myself. I ordered some EBL batteries, they are red with white stripes? Haven't tried them butt they are labeled INR which are prettry good from what I understand. I also bought Trustfire batteries, which everyone says to stay away from! They are ICR, considered more... I think dangerous? Difficult? I just ran them down and recharged them, 900mAh 14500's took 867mAh charge. Pretty aCcurate. When you see claims of 9,900mAh, 12,000m,Ah, stay away from them. If Samsung, Sanyo, LG, Sony and Panasonic don't make a battery over say 1200mAh for a 14500, how does GTL fit 12,000 in the same size package, stay away!
Do a lot of research on different battery chemistry, their discharge rates and what you are using it for. These high discharge rate batteries for vaping arer expensive, you don't need them for sa flashlight. And of course ask plenty of questions on here, there are guys that can tell you EVERYTHING about lithium batteries! Good Luck, feel free to ask me anything too.
DoinStuff