The battery was old and had gone through many cycles. It was not holding charge like it used to and would often require charging throughout the day.
The repair went really well. The instructions were easy to follow as well as the plethora of resources on ifixit as well as youtube. The only annoying part was to get the sticky tape off the battery. It's not really a fault of anyone's really just an inconvenience of the material.
Keep track of all the screws as they are really tiny. Magnetic screwdriver is amazing. The sticky tape is annoying so keep at it and eventually it will come off.