player turns itself off with battery half full

the battery of my clip+ 8gb lasts about 5 hrs. usage mp3, no radio, no sd card, display brightness turned down a notch. i wonder if the device is defect because the battery lasts so much shorter than the promised 15 hours. this is way off. also when the battery is about half full the player turns itself off. then it reports that the battery must be charged. should i return it for exchange or can it be fixed?

And you’re sure that the Clip isn’t running when you thought you had turned it off, right?  (Don’t laugh–it’s happened to me!)

If you’re sure you’ve been shutting the player off and it still runs out after 5 hours, it’s defective–I’d exchange it where you bought it or contact SanDisk for a warranty replacement.

i am absolutely sure it was turned off. this type of shutdown happened every time, not occasionally.

Time to exchange, then …