....to just stop working as well as it used to? I always thought that it either worked or it didn't --that it would eventually just go out and not charge at all. I was having problems with almost all my batteries being weak or not lasting very long even right after a full charge (I have both a wall charger and an old USB charger), so I ordered another USB charger (this one has a cord). It seemed to help quite a bit, but now I'm thoroughly confused. 
