Most small electronic items have USB chargers today. It means they may need to get charged off from another device, just like a laptop or desktop computer, that has a USB port. Despite the fact that USB charging has grown to be pretty pervasive, it could also be inconvenient. However, power bank chargers supply a fast, more convenient, and also safer solution.
http://www.youtube.com/watch?v=lm3_B3efcVE
http://www.dailymotion.com/video/x2opk4u_untitled