From the Kindle quick start guide.
"Charge your Kindle by plugging it into a U.S.-compatible
electrical outlet.
You can also detach the USB cord
from the power adapter* and connect it to a computer
to charge your Kindle or to transfer data."
Do you have the quick start guide? There should be a users guide loaded onto your kindle also. Here is a link to them online.........download the pdf versions to your computer.
http://www.amazon.com/gp/help/custom...deId=200317150