Battery Conservation Tips

Since I bought a MacBook Air from our first delivery of them earlier this year, I’ve grown more and more attached to it. I take it with me when I travel, and it serves as my main home computer. Combined with the AirPort Disk functionality of the newest AirPort Extreme Base Station, the MacBook Air’s relatively puny hard drive isn’t a problem.

I have two quibbles with the Air, though. Firstly, it’s so light and whenever I keep it in my backpack, I forget it’s there; I sometimes toss the bag into the car or into a corner of the office. Thankfully, no damage has come from this! My second quibble is with the battery. Apple advertises a five hour battery life for this machine, but I’m hard pressed to squeeze two hours from it unless I employ some extreme power conservation. Also, the battery takes a very long time to charge. In an airport, between flights, I could charge the MacBook Pro quickly and efficiently for the next flight; with the Air, no such luck. It takes an excruciatingly long time to charge the thing.

QuickerTek announced an external battery pack for the Air that is supposed to give a total of 16 hours of battery life! Check it out here.

Here’s my list of battery saving tips:

• Lower the display brightness all the way down. Doing this will generally double the estimated remaining battery life if you were set to full brightness beforehand.
• Disable keyboard backlighting.
• Ensure that Energy Saver is set to spin down hard disks when possible.
• Put your computer to sleep whenever you’re not actively using it, like when you’re on the phone, in the bathroom, or walking the dog.
• Eject optical disks. They spin almost all the time, taking power, even when they’re not in active use.
• Have lots of RAM installed. This helps prevent excessive virtual memory use (virtual memory is hard drive space that’s turned into “virtual” RAM. When the computer needs more RAM than is physically installed, it’ll dip into virtual memory reserves, and cause the hard drive to work more than it really has to.
• Consider using Activity Monitor to kill the dock process, which owns Dashboard. If you’ve invoked Dashboard, killing the Dock will free up all the memory it used. Consider disabling Spotlight as well.
• If you’re on the road, odds are you don’t have your Time Machine disk with you. Turn Time Machine off while you’re traveling.
  Use your iPod for music, not the computer; don’t charge your iPod unless absolutely necessary.
• Turn off auto-save features in your word processor. This feature spins up the hard drive all the time, consuming lots of power.
• Don’t keep unused Applications running in the background.
• If you use Quicksilver (and you should, by the way: http://quicksilver.blacktree.com), ensure that it does not re-catalogue, which is hard drive- and procesor-intensive. Set it to rescan every 24 hours.
• Turn off Bluetooth and AirPort unless they’re actually needed.
• Mute the sound.

It’s not always practical to use your laptop is such a minimal way, but following these guidelines my MacBook Air will ALMOST last for five hours on a single charge.