The rechargeable batteries in MacBooks, iBooks, PowerBooks and iPods are categorized as “lithium-ion.” Lilon batteries, as they’re often called, provide reliable power for everything from cell phones to laptops, supplying significantly more power than nickel-based cells. Basically, Lilons are not your father’s Duracell.
The following tips will extend the life of any Lilon battery whether it’s playing games, answering e-mails on your laptop or watching a movie on your iPod or iPhone.
Tutorial: Maximizing iPod and MacBook Battery Life
The tutorial above even shows you how to use the Terminal in OS X to check your current battery capacity and help you figure out when you need a new battery for your laptop.