I have been looking everywhere for something or someone to tell me the difference between the Trusfire grey (or gray), blue and black and red batteries. Specifically the 14500. There is quite a price jump between them and want to know what the cause for the different prices. I have a couple of blue ones but I am about to build a 5v mod and need a couple of backup pairs. Any help with this would be appreciated. Also I found a few places to get them any links to were to get them cheap in the U.S.