My battery would completely drain at 30%.
The repair went very smoothly. I followed everyone's advice and took my time. The only hiccup I had was removing the battery adhesive strips. However, a little heat from the hair dryer and an old gift card made short work of the situation.
When removing the tiny screws, use the tray your new battery came in. Works great for keeping track of them. By the way, they're super tiny!