Since apple cannot replace the battery of my MacBook Air. I've decided to buy my own battery at Amazon. I know some people here would refer Newertech batteries. I've had a bad experience with them. I replaced the battery of my old MacBook Pro Early 2011. I followed all the recalibration steps for the battery. Guess what a few years later the battery cycle is still at 5 cycles and the battery would die down after using it for 1 1/2 hour. I've decided to purchase a battery at Amazon. I just want to know if you have to do anything special after you install it. Do you need to recalibrate the battery again? Is that really needed? I prefer just installing the new battery and just charging it until it becomes full.