I purchased a couple of these Dynex mobile batteries last month. It’s essentially a mobile charger for your devices when you’re on the road. All you have to do is charge the battery pack when you’re at home. Then you can use the battery pack to charge your mobile phone or device on the road when you don’t have an outlet nearby. I’ve tested them and they work fairly well. The mobile battery includes a USB cable to charge the pack. To charge your mobile device, you just reverse the connection. However, I had to use my Samsung cable when I wanted to charge my Samsung phone with the Dynex battery pack. Note: you can also use the battery pack to charge your iPod and iPhone. Best Buy has the Dynex Lithium-Ion Mobile Battery Pack on clearance for $10 and they are available in multiple colors.