In a telephone shop, the otherwise dubious seem to me from the outside, they were very kind to me and looked the same at first glance, that is no longer the battery is charging, apparently has then a minimal dent in it. My sister had a similar problem. When she was on vacation, they had to turn off the phone, otherwise, according to an expert exists explosion hazard. Nevertheless me the battery for 25 euros was too expensive. I found what I was here at Amazon. The price is acceptable for the battery, yes, exactly cheap. Yet I get original item, which is identified by Samsung and when I put the car battery for a gefrusteten crash with the old part, this was still half charged and could walk immediately in use for half a day!
The problem is I think just what everyone does: It makes the device despite better judgment when charging is not enough. So the battery in continuous operation will make someday limp.