One of the first applications we install whenever we end up with a new MacBook is coconut-flavour’s coconutBattery (Free). It’s been around for as long as we can remember, and just recently, version 3.0 was released. This free little app will tell you everything and anything you might want to know about your Mac’s battery. It might even save you a trip to the Genius Bar.
Launch coconutBattery, and it’ll instantly display the current charge as a percentage as well as in miliampere-hour, or mAh. You’ll also see the maximum charge level, rated against the battery’s original capacity. Based on the number of load cycles the computer has been through, this number may be significantly lower than where it started out. Among the other granular details presented, there’s a “battery details” tab that gives you the date it was manufactured, serial number, and more.