Most small electronic items have USB chargers today. That means they may have to get charged from another device, such as a laptop or desktop computer, that has a USB port. Despite the fact that USB charging has become pretty pervasive, it could also be inconvenient. However, power bank chargers give a fast, far more convenient, and even safer solution.
http://www.youtube.com/watch?v=xQaWu6dgYx0
https://vimeo.com/126600189
