Avantree Juna, Ultra-slim Portable Battery Charger, 3400mah, Portable Charger Power Bank with Detachable USB Cable for Fast Charging At only 12.6mm, this ultra-slim portable power pack fits easily into your bag or pocket for charging on the go. This portable charger boosts a battery from 0-100% in around 2-3 hours for most phones. A charge time of around 4 hours is achievable with a 1A travel charger (not included). The power bank adds 12 hours of additional talk time and a whopping 300 hours of standby time to most devices. And it is compatible for Samsung galaxy S3/S4/S5, HTC one, Nokia, Blackberry and other android smartphones. A detachable micro USB sync cable provides a space-saving, tangle-free solution for carrying an external battery pack on your travels. Built with safety and reliability in mind, this portable charger's Grade-A lithium polymer cells protect the gadget from issues such as overheating and overloading.