How to Use Mavericks' New Tools to Boost Your Battery Life

If there's one major point of emphasis for Apple's new desktop operating system, it's battery life. According to Craig Federighi, Apple's senior vice president of Software Engineering, if you were to take the newest MacBook Air and install Mavericks, you'd get an hour longer to browse the web - even if you don't take any other battery-saving actions. In my personal experience with a 2011 Macbook Air, I saw similar gains. By itself, that's reason enough to install Mavericks. But along with that automatic battery savings, Mavericks includes a powerful suite of tools that can extend your laptop's life even longer.

Apple's approach to power consumption is simple: If you're not working on a process right this moment, OS X drops it into the background and has the CPU more or less ignore it. Sure, your screen uses a lot of battery, but you can't really turn that off. You can, however, re-arrange CPU processes so the processor is idle for longer. That means cycle-hogging processes like Spotlight and Time Machine now work in the background.

Nap time

Apple's new suite of energy saving settings, App Nap - not to be confused with Power Nap - doesn't really have an interface. Which is fine! The whole idea behind App Nap is that it runs in the background, looking for apps that fit certain criteria like whether they're maximized or currently downloading or playing media.

That doesn't mean App Nap can't benefit from some occasional monitoring. The venerable app, Activity Monitor, has a new tab labeled 'Energy' that lets you do just that. It lists your currently running programs and daemons, their energy usage, and whether the application is App Nappin'. If you see an app that has a disproportionate energy impact, kill it, and consider uninstalling it. For instance, I didn't realize that Spotifree, an adblocker plugin for Spotify, was treating my CPU like an all-you-can-eat buffet. I uninstalled it, naturally.

If there's a program that you don't want to sleep in the background, here's how you shut App Nap off on an app-by-app basis.

The status quo

Of course, most people aren't going to be dipping into the Activity Monitor on a regular basis. That's why Apple's put a Sparknotes version up in your status bar. It essentially lists the top two or three apps from the aforementioned Activity Monitor Energy tab. However, it's possible to see 'No Apps Using Significant Energy,' which means, hey, your computer is chilling at the moment.

While this information will be useful on an individual level, third party developers will also be increasingly aware of just how much energy their apps use ... because they'll hear it from end-users.

Consider Safari

While you might not want to switch from trusty Chrome or philosophically pure software like Firefox, getting the longest battery life on your Mac means you should consider using Safari 7. Apple has added a ton of features to the latest version of the desktop browser, and most of them work in service of getting you additional minutes on your battery. For instance, each Safari 7 tab now runs its own process (as Chrome has done for years), and Apple dedicates resources to the tab that's visible and cuts them from tabs in the background. Sometimes web apps can harbor memory leaks in a background tab, especially in Chrome, which is most likely the biggest non-media power hog on your machine. But if you're not actively using the app, Safari will throttle it.

Apple's had a long-running beef with Adobe's Flash, but the reason isn't corporate politics. It's because Flash kills batteries dead. Safari 7 includes a nifty program that ends up being half adblocker and half power saver. It's called Safari Power Saver, naturally. It prevents browser plug-ins - Flash mainly, but also programs like Java and Silverlight - from autoplaying, especially if the media is in the margins of the page. Most of these autoplay videos are annoying ads, but if you really want to view it, mousing over and clicking starts the video. In fact, if there are sites that you browse regularly that load obnoxious plug-ins, Safari features a menu that lets you set plug-in permissions on a website-by-website basis.

While many software updates promise improved battery life, few actually deliver. Most of the time when we talk about improved battery life, we're referring to hardware, like Intel's Haswell chips which can keep laptops powered for 12-hour stretches. But even if you're not using the latest and greatest Mac, Mavericks will genuinely improve your computer's battery life.