Charging Battery. I put my Coby mp300-1G in the USB port to charge. Once it is plugged in, on the

Question

I put my Coby mp300-1G in the USB port to charge. Once it is plugged in, on the screen of the Mp3 player it states MSC. I leave it on for hours to be charged. Once I feel like it should be ready I take it out and the battery tells me that it is all the way charged until 3 seconds pass then it goes back to one bar. Please help!!!!