My older ipod wont charge

I have a 30 Gig white older Ipod that I believe I bought in 2005. I used it a lot everyday for 5 years and then it went into storage for the next few years and yesterday I broke it out of storage. I tried to charge it from the wall and from the USB and nothing happens. When I put it into the dock it does show the battery icon with a exclamation point through it. I really just want to sell it on Ebay and if it's an easy fix I can fix it but I do not want to send it out. Do you think that the battery just might be shot? Any help would be greatly appreciated. Thank You.

TG