MacBook Batteries
If you haven’t spent any time in Energy Saver in your MacBook’s System Preferences, now is the time. This is the section where you can enable a number of battery-saving options like dimming the display, hibernating hard disks at certain times, and so on (make sure you turn Power Nap off here).
While you’re in System Preferences, you should also swing by the Keyboard section and make sure that your keyboard’s brightness is set to dim in low light – or just set it as low as possible. MacBook users may not care as much about keyboard brightness as saving battery life.