I haven't even seen the product since the prototype. My understanding is that there is no battery door, and therefore the battery is internal. IF there was a battery replacement, it might be at www.samsungparts.com but again, it would have to have an accessible door.
Have you tried turning off the screen when you're not using it, and dimming the brightness a little? Often times, those two settings will greatly prolong the use of the charge.
I am only getting 2 hours play from my player. Is this normal? Is it possible to replace the battery and if so where can I purchase the batteries?