I am a so-called power users and am therefore constantly with the mobile phone online, here's an email, because sometimes surf and frequently also watch YouTube. I have also connected a headset with Bluetooth in the car and at Navi. Can "unfortunately" the mobile set five minutes from the mobile phone. So if a battery for his Galaxy S4 examined, with whom he gets along comfortably one day might be a match for the replacement battery from Mumbi.