Hello There, since I I have the battery and at the same schutzhulle took finally to the Apple iPhone 4 battery no more problems. Had before a different battery case but that was always empty so quickly. Important, I also think that it has been certified by Apple otherwise you have no guarantee on the device more! And you could tell the difference between a device which has been certified by Appel also for the Apple iPhone 4 ... the holds then also the promises which the provider BLACBOX promises! BLACBOX PowerPack Plus Apple iPhone 4 (black) certified by Apple and released! No Garantieverlußt! The thinnest iPhone 4 Battery Case by all! (This Powerpack also offers 210 hours standby & 10 hours talk time! Incl. Display ...