Portable battery chargers that are often used to charge the cell phones and other similar items and control the power supply frequently are nowadays called Power bank. Power banks need a USB interface to charge the portable speakers, Bluetooth, headphones and mobile phones. They are available in different shapes and designs in the market. Nowadays they are mostly used by everyone because of easily carrying and excellent performance. The best thing of these power banks is that they charge the battery in minimal time and not harmful for cells. Either you are in traveling or anywhere else they are the best battery supporters for your accessories. Most of the power banks give multiple charging at a single time, so they save the time as well. So, grab your power banks now from Hard Disk Direct for uninterrupted power supply of your devices at cheap cost.