Re-Fuel Weekender 5200 Power Bank Battery Charger - 5200mAh 1A USB Port External Battery Power Bank | Portable Phone Charger For iPhone, Samsung, and Android Smartphones (Black) Power Bank comes pre-charged and ready to use right out of the box. 1 amp of charging power gives you a quick charge whenever you need. Portable design fits comfortably in your bag or jacket pocket. Will hold its charge for months until youre ready to use it. Plug it in overnight and youll be recharged and ready to go the next day.