Default replacement battery for Galaxy Player 5.0 YP-G70 or how to fix dead player?

My Galaxy Player 5.0 was working just fine until I went to turn it on the other day and nothing -- plugged it in to wall charger and to PC via USB and not even the battery icon will come up. The back of the case gets warm, but it won't power on. I tried contacting Samsung and they told me to do a hard reset (hold power and up volume at the same time), but that didn't work. They sent me a link for a service request, but it was a broken link. At this point, I'm assuming it's the battery.

I found a link to how to open the player and also found a post with batteries compatible with the Galaxy Player 4.0, but nothing for the 5.0. Any help would be appreciated - either with battery replacement info or with other suggestions on how to fix the player.