iPod Frozen HD new
Yes, it could be the battery. So for the cost of a new one go ahead and change it. The other thing that I would try to do is make sure that the HDD cable is seated properly, and I would change it as well. Especially since it is a new drive. If none of the above work you may need to look for a new logic board. The price is really not that bad considering the cost of a new iPod and the 5th gen is really a great device. But do one step at a time and always double check your work. Good Luck.