HOW DO I STOP MY BATTERY DYING IN STORAGE?

If your Mac laptop is going to be left unused for a long period — months rather than days or weeks — you should charge it to 50% before you put it into a dry place away from temperature extremes. This is because if your battery is flat it could go into what’s called a “deep discharge state” that won’t hold a charge any more; a fully charged battery may lose some capacity. Apple recommends that if your Mac will be in storage for longer than six months, you should half–charge it every six months.