c250 Won't Fully charge

When I hook it up to the USB, I see that the battery charging icon is “filling” and I wait until it’s “full”… Then when I disconnect it, it shows only “half full.” 

No matter how long I charge it (and in each instance it will show FULL before I disconnect it from the USB), when I start using it, the batt. indicator always shows HALF charged (never a full charge). 

I am lucky if I get a couple of hours of play time before the battery is drained and I have to charge again.  Is this a bad battery?  And if so, can I still get a replacement battery for this model?