I want to buy a used Ipod for my new RT A&C but the seller says the battery is pretty week. I don't care as long as when I'm using it on the Spyder it is charging. Another way to say it is....I only see the one port on the bottom of the IPOD which normally has a USB connector for the computer on the other end. But when that port is used with the spyder cord to plug into the right port in the top rear storage bin I wonder if it plays music and charges?