"Please Wait... Very low battery."

So I have an iPod classic 30GB. All of a sudden, it stopped charging properly and kept showing that "Please wait... very low battery" sign. I tried resetting it and stuff and it doesn't work.

Funny thing is that I took it to the Genius Bar and when the guy plugged it in his computer, it started charging and working so he told me it was fine. However, when I got back home and tried to do it, it still kept showing the same message. I even updated my iTunes and everything. By the way, I use a PC so idk how that may contribute to it.

What should I do?