Macbook Air battery needed to be replaced.
Instructions were clear and easy to follow. Now my battery doesn't die so quickly and holds a charge.
Make sure you keep the screws in a safe place while you're changing the battery.
T5 Torx Screwdriver
P5 Pentalobe Screwdriver Retina MacBook Pro and Air
MacBook Air 13" (Mid 2011/Mid 2012) Battery