I was already skeptical before buying. A few days too late Unfortunately for me, I just got the issue 10/2015 of c't computer magazine and therefore certainty. The c't article "Everything just faked" describes a disastrous state on the battery market. Although plagiarism run at the beginning very well but quickly lose the capacity. It also describes how to recognize a real original battery's S4. Conclusion: My battery is not an original. Goods returns.