Etekcity Wingman 5200P - 5200mAh 5V 1A Slim, Portable Power Bank/External Backup Battery Pack w/ Built-in Wall Charger & USB ports for smartphones, etc from Apple, Samsung, Blackberry, Droid, etc & almost any other rechargeable device Charges electronic devices that require a 5V power source Built-in AC power plug  use it as a wall charger too! (110-240V) Automatic shutoff to prevent battery drainage and preserve charge High-quality battery cells for reliable long-term performance Portable size for maximum convenience  fits in a pocket or purse