Strange Charging Problems

I'm currently in dorm rooms at a summer camp, and am trying to charge my ipod during the night, as I usually do. However, I'll plug it in, it's around 25%-50% (estimate) charged, but when I wake up in the morning (7-8 hours later), it's been drained to around 5-10%. Even if I plug it in and it's almost full, it drains.

Why is this? I also try to plug it in the morning after, and it will charge to 50%, then drain back down to 10%. I don't understand. The charger works in outlets at my house and in the main building, but not in the dorms. Is it a problem with the outlet itself, or my charger? Someone said it might be power surges, but I'm not sure.

Help?

 

I don't want to restore the device, as that would erase all my music, vidoes, etc.

 

Has anyone seen this kind of thing before? Is it my iPod, my charger,or the outlet itself?