Just throwing out there, Apple accepts their own batteries in any condition. I showed up to one of their stores with a friend's swollen (spicy pillow) old MacBo

Just throwing out there, Apple accepts their own batteries in any condition. I showed up to one of their stores with a friend's swollen (spicy pillow) old MacBook battery in a metal trash can and they put on hazmat gear, came outside the store, and took care of it. They curiously also have you sign some paperwork stating you're not getting the battery back. I'm not an Apple hardware user or fan but I was pretty impressed with how professionally they took care of that.