Run on battery whenever you need to and plug it in whenever you can. You can plug or unplug at any time, regardless of the charged percentage. Just make sure you don't run on AC power all the time, as your battery needs to be used regularly to stay healthy. This should answer most, if not all, of your battery/charging questions:Hi, I rarely use my macbook, maybe once a month or even less. Is there anything I should do to improve battery lifespan? Maybe discharge it fully before storing it or is it ok to just shutdown?