Sub-standard battery life has been one major issue that's affected Samsung's Galaxy S line since the beginning. With the Galaxy S4 and it's slew of new features such as smart scroll and air gesture to name a few. we expect the hit on battery life to be substantial. Enter Incipio's offGRID Backup Battery, which is the best option for a case that's also a 3100 mAh battery. Set to ship in three weeks (preorders are available), the offGRID will give an additonal 10 hours of battery life. Sweet.