There are a lot of battery solutions for the iPhone out there, but the Mophie Juice Pack Reserve is a unique and convenient alternative. The Juice Pack Reserve is significantly smaller than other battery packs and also has a keyring making it easier to bring with you. For charging, there is a USB cable that can be used with an AC adapter or a USB Port, it then neatly tucks back into the device itself. The 30-pin dot connector is protected by a flexible attached cap that rests on the side of your device while you charge. The Mophie Juice Pack Reserve will give you about a half charge, just enough time for you to get back to a wall outlet. There is also a (PRODUCT) Red version, both available through Mophie.