UNU Ecopak iPhone 5 Case -Snap-on Case and Detachable Battery (Silver/Black) Innovative detachable design, the uNu Ecopak Battery System provides more than double the battery life without adding bulk. Choices of 7 Colorful Snap-on Cases, plus choices of 3 stylish detachable battery, the total 21 stylish combinations makes ECOPAK one of the best cases for iPhone 5 in the market. This uNu Ecopak Battery System utilize standard USB port to provide power to your iPhone 5 via original lightning cable. The featured standard USB port enables power sharing with other devices. It also reduces the need of buying a new battery when purchasing a new phone. This uNu Ecopak Battery System features 2500mah capacity, which adds over 10 hours of talk time, 42 hours of music time, 11 hours of web browsing, and 310 hours standby.