Ipod won't turn on

My Ipod won't turn on unless it is connected to the computer. Right now all I can do is use it as a drive. I have tried everything and it only turns on once I plug to the computer and then I have to look for the device in my computer, open and eject to disconnect. That's the only way I can listen to the musics. Once I unplug the usb it turns completely off. THe other problem I have is that the battery symbol is always empty only is fully in green when is disconnected with plug still on the PC.. I am becoming desperate because it's new. help please...