A friend of mine was considering purchasing an old(ish) MacBook Pro and wanted to check the battery life as they arranged the deal.That when I thought it might be worth sharing this little tip, given lots of people will be selling Macs to get hold of a new MacBook Air.Battery cycles for battery health That when I remembered this little-known, but really quite useful (and mercifully short), Mac tip that helps you get some kind of insight into your Mac battery health.[ Related: Apple's place is in the enterprise ]The batteries used inside Macs are built to handle a number of battery cycles.