This is probably a stupid question. I have an Opus BT-C3400 I bought from the guy on ebay that was reported here to be an official seller of the chargers that say 3400 and not 3100. Version 2.1 software for it. It says FULL at 4.11-4.16v. I have yet to have a new, used, protected, or unprotected cell charge beyond that if it is starting off over 4v. I know resistance, ect causes the cells to not all charge to the full 4.2v, but I’ve had the same results on over 20 different cells (Sanyo laptop pulls, tenergy, trustfire flames that are legit, and a bunch of new panasonics protected and unprotected). I have noticed if it says full at say 4.11v, I can immediately remove it and and put in a different slot and it will charge some more. The slot that charges it more is random. If the cell has been used and in the mid 3v’s it will charge it all the way to around 4.18v. I guess my question is, why is it saying full when it will charge it more on a different slot and why does it charge to a higher voltage if it starts off lower? Is this normal behavior?
I believe that this problem was reported in the group buy thread and the fix is also posted there. I'd suggest if your not sure what you are doing not to do the mod incase the charger is damaged.
ummm, that’s gonna be some reading. I’ll have to read through it and see if I can find the solution. Thanks for the info.
Thats why I did not go looking. Its near the end somewhere. 
Here it is, post # 325: ( and some other nearby posts)