Keeping your phone alive isn't just hard, it can be straight-up impossible. From too many apps to constant email checking, sooner or later your battery is almost certainly going to die. Luckily this power bank hauls enough juice to charge your device up to four times. It's small, and features a cool design with two USB ports, so you and a friend can power up at the same time. LED indicators let you know how much power is left, and an auto-save function turns the device off when not in use.