I received the red, black, and gray-labeled 18650 batteries from Manafont some time back. Just used them straight out of the package. Never noticed a problem, but I notice that I've had both on the charger for quite a number of hours and they never topped off (with green light coming on with charger).
Are these super-slow-charge batteries? The 2400 blue Trustfire cheapos take several hours at most. These seem never to top off. No change tonight. However, I do notice when I take them off of the charger and use them in the lights, they are brighter.