I am always running out of power when using my phone or iPod nano, so this was going to be my first experience at buying an extra boost! The charger does the job no doubt about it , the reason for the four and not five stars was the build quality. I thought perhaps the usb fittings may have been just a bit snugger in fit, I would not use it when jogging, maybe light walking. It is also extremely light, but I like that because I use it a lot when traveling. I very much like the added led light attached to it, very nice touch. It is also really easy to use. I am glad I bought it, and I think for the money most other buyers will be to.