Re-Fuel Adventurer 10400 Portable Power Banks Charger - 10400mAh 2-Port USB Portable Phone Charger Power Bank for iPhone, iPad, Samsung Galaxy, and Android (Black/Green) (I00029449) Power Bank comes pre-charged and ready to use right out of the box. 2.1 amps of charging power gives you a quick charge whenever you need. 2 in 1 cable design fits securely in your backpack. Will hold its charge for months until you're ready to use it. Plug it in overnight and you'll be recharged and ready to go the next day.