The battery life of the brand new MacBook Air is an enviable 12 hours (or more, as some reviewers found). If you can’t afford to run out and buy a new one, don’t worry: there are still things you can try to help preserve and extend the life of your older MacBook’s battery.
Whether you’re traveling, at an off-site meeting, are not able to get the one table at your favorite coffeeshop next to the power outlet, or just cannot charge your MacBook for an extended period of time, you should know these secrets of power-saving. Check the condition of your battery. Before you attempt to maximize the health of your battery, you first need to determine if your battery is healthy or not. The easiest way to do that is to hold down the option key as you click on the battery status icon to access the Battery menu bar extra. You want to see a condition of Normal. If you instead see a condition of “Replace Soon” you may need to bring your Mac in for service and likely get the battery replaced. Determine your battery’s cycle count. You find this by clicking first on the About this Mac menu in the Apple menu. Then click on the More Information button then the System Information button. In the left column, select Power from the list and locate Cycle Count. You can typically expect to get about 500 to 1,000 cycles out of your battery before it reaches 80 percent of its original capacity, depending on the model year of your Mac. Use a better battery monitoring utility. There are utilities that make gathering information about your battery’s health much easier. One is Battery Health (Free, Mac), which will tell you the original maximum capacity possible for your MacBook’s battery, which you can compare that to the maximum capacity the battery is currently reaching. An alternative utility is coconutBattery (donation, Mac). coconutBattery has the same information, but will also upload your battery’s statistics to its online service for comparison to other batteries in use by Macs similar to yours. Calibrate your battery. Calibrating your battery basically maximizes its full charge potential by first fully charging it, then fully draining it, and finally fully charging it again. Apple does not recommend leaving your MacBook plugged in all the time. Furthermore, Apple even recommends charging and discharging your MacBook’s battery at least once per month — it even has a calendar event to remind you. Restore Energy Saver defaults. The first step you need to take to ensure that you are getting the most out of your battery as possible is to restore your Energy Saver setting to their default values. Open up the System Preferences and select Energy Saver. Make sure that the Battery settings are exposed and click on Restore Defaults. This should turn the Mac off after 10 minutes of no use, the display off after two minutes, allow the hard disk to sleep when possible, and slightly dim the display when on battery power. Do not enable power nap, as that will consume power even when you think your Mac is sleeping. Dim all the lights. This includes dimming both the screen and keyboard lights. The function keys on the keyboard are the best place to adjust the brightness of both. Keep the display on a setting as low as you can tolerate and turn the keyboard backlight off entirely if you can. In the System Preferences for the Display be sure that you do not allow your Mac to automatically adjust brightness. This goes for the Keyboard preferences too: there is no point in having your Mac adjust the keyboard brightness in low light if you intend on keeping it turned off in the first place. Turn off the screen saver. After setting the Energy Saver back to the default settings, the screen will be turning itself off after just two minutes. And since there is no screen saver on the Mac that consumes little to no energy, just turn the screen saver off entirely. To do that, you need to set the Start After property to “never.” This is located on the Screen Saver tab within the System Preferences for Desktop and Screen Saver. Get rid of Adobe Flash – If you do not feel you need Flash, then do not install it in the first place. If you have it, unfortunately Adobe does not have a convenient kill switch for Flash in such situations. But there are apps like FlashFrozen ($0.99, Mac) and FlashBlock ($0.99, Mac), which are both available in the Mac App Store. Either of these will turn off Flash and allow you to browse the internet Flash-free. Stop sharing services. Only turn on what you need to have on. From within the System Preferences open your Sharing settings, and see if there are any that are turned on that you no longer need. Especially when you are out and about on public networks, there is no good reason to leave on your sharing services. Your best energy-saving option is to have them all off by default. Block incoming connections. It’s also a good idea to block all incoming connections. This will prevent applications from waking up and performing work in the background and using precious battery. This includes applications like iTunes, Dropbox, Messages, FaceTime and even Skype from receiving an incoming connection. These apps will be able to make an outbound connections just fine, so this setting will not render the apps completely useless. Disconnect from the network. If you don’t need to be connected to the internet, be sure to turn off your Wi-Fi radio. It is actually a good idea to create a network “Location” that basically connects to nothing at all. From within System Preferences, select Network. Create a new Location by first Editing Locations and clicking on the “+” to add a new location. Label this location “Disconnected” and click Done. Make sure that your location is set to the newly created “Disconnected” and start removing the default services that were assigned until no services exist. Once you have removed all network services from the location, click Apply. This will keep your Mac from connecting to the network entirely. Turn Off Bluetooth. First, if you are one who carries around a Bluetooth mouse or — heaven forbid — a Bluetooth keyboard, just stop. And get used to using what is already attached. But if you only use them when you are at a desk with a power adapter attached, then be sure to turn off your Bluetooth radio when you are out and about. There’s no reason to leave it on if there is nothing to connect to. Eject discs and network drives. No, not your Macintosh HD, but any network drive that you typically attach to and do not need access to while you are looking to conserve power. Older MacBooks with SuperDrives should eject any media they have in them. Basically any drive or attached device that has mechanical parts or requires access over the network should be disconnected if at all possible. Detach peripherals. Do not leave SD cards in your SD card slot, or USB thumb drives attached. Definitely do not charge your iPhone or iPad by leaving it tethered to your Mac either. In fact, almost anything that is attached to your Mac will increase the drain on your battery and therefore shorten your battery life. About the only peripheral that could cut down on power consumption is headphones. At least they will switch off the slightly more power hungry internal speakers. Download, don’t stream. If you are planning on watching videos and listen music, do so locally. Download your media files before you get yourself into a situation where battery life is critical. Like Flash, streaming music and video services wirelessly can run your battery down fast. Adjust your security settings. Since you now have your Mac going to sleep and turning off the screen more often than you are probably used to, you may what to change your security settings so that a password is not required immediately. While I would usually recommend that you have it set to immediately require a password, in cases where you have your Mac optimized for power savings, constantly signing in may be more inconvenient than you can tolerate. But still keep the setting to a short period of time. Postpone backup and syncing services. Like the security setting, take this power saver setting with a grain of salt: use at your own discretion. Backing up your Mac is an important task, and obviously there is nothing to be backed up when all of the power has gone out. But temporarily disabling your backup and online sync services may add some time to your battery life. Especially if you share access to a team account and other members of the team are constantly updating large files that you are not particularly interested in at the moment. For instance, I do know that both Dropbox and Carbonite can be paused. Stop Time Machine. Time Machine, on the other hand, has a setting where it won’t back up when on battery power. From within System Preferences open the Time Machine settings and click on the Options button. Here you should see a check box that will allow you to turn off Time Machine backups when you are using the battery. Monitor Your Mac’s activities. Sometimes you just don’t know everything going on under the hood of your Mac. Apple even warns us that runaway processes can drastically shorten battery life. To identify which process are running. launch the Activity Monitor located in your Applications Utilities folder. Select the CPU tab and make sure that all processes are being watched. Sort the table by CPU % and see if any process is consistently using more than 70 percent of the CPU. Before you kill the process, you will need to figure out exactly what the process is. You may have to install an update for that particular piece of software, figure out why it is using up so much of the system’s resources, and ultimately decide if it is worth having installed on your Mac in the first place. If all of this seems overwhelming and unnecessarily complex, well, it is. That is why the recently announced MacBook Air with a potential battery life out of the box of 12 hours is really big news. And if you were paying attention at the WWDC keynote earlier this month, you would have heard that the next version of Mac OS X, Mavericks, will be looking to take some this complexity our of the equation by making the system smarter and self-adjusting. Until then, we are stuck with OS X Mountain Lion and a whole lot of settings to contend with if we want to maximize our batteries’ full potential.
This post was corrected on 6/26 to note that the MacBook’s battery reaches 80 percent of its original capacity after 500 to 1,000 cycles; it does not “lose 80 percent of its original capacity” as originally stated.