I've got some strange symptoms when charging with a particular charger. More exactly, I have one 5V 2A wall charger, original from Samsung, and a cheap USB to MicroUSB wire. This is what happened: 1. I charged my Lenovo Tab 2 A7 one evening up to 100%, then unplugged it for the night. The following morning it was dead and wouldn't start up. First thought it was that it got bricked somehow, but it turned out the batter actually died. I charged it at work (with another charger) and it worked fine from there on. 2. Using the same charger, I charged my Samsung Galaxy S4. This time I charged it at lunch and I could see the battery dying very fast over the rest of the day until I recharged it the evening with another charger. I presume that the same thing happened with the tablet, only that I didn't see it discharge overnight. Does anyone have any idea what could cause this? I presume that it is the adapter's fault. Probably unrelated, my Galaxy S4 has the tendency to show me a certain percent for the battery when I close it, only to go up 2 or 3 percents when I open it again after twenty minutes. I think this has to do with me not updating my Android for a while, though. Any help is appreciated. Thanks.