While I really wanted this unit to work and provide the additional power for extreme emergencies; the unit I received felt hard to wind and it never adequately charged my cell phone during my test. In fact, it seemed as if the gears were grinding without the benefit of lubricated bearings. My phone indicated slow charge and stop accepting the charge altogether. The unit however did charge a usb battery bank well. It does take a long time to charge up though. I had to purchase a usb to powerpole converter separately to make the unit work for my application. After the second or third try, the pin that holds the strap in place come undone. I must say that Lion Energy was superb in providing a RMA and label for Return Shipping. A first class organization. I must have received a defective unit, but after going through all the trouble of connecting an addition device (USB dc-dc block convertor), I decided not to try it again.