I bought a MacBook Pro 15.4" in September and the battery life is nothing like what is advertised. I'm struggling to get 4 hours out of it with wifi off and Ethernet as my network connection. The spec I choose wasn't the best, either: it only has the 2.2GHz Core i7 with the better graphics card model, no other additions.

I bought it because of its great battery life, I've tried turning screen brightness down and the keyboard backlight off and still nothing. I am mainly using it to type up lecture notes in the lecture so I am running it off battery power only using Word and PowerPoint. Should I be concerned and take it back to Apple? I know the Core i7 is power hungary but, still, this is ridiculous as it's less than a month old – I was expecting to be able to use it for a full day without the battery dying.

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    Do watch activity monitor to see if any processes are taking significant CPU over time. I've not seen Office 2011 be horrible, but in the past have made notes in Pages or TextEdit to save CPU when working on battery. If your CPU load is less than 20% - there might be some other cause (like GPU engaged) - have you looked into the CPU usage?
    – bmike
    Commented Oct 4, 2011 at 1:10
  • Yes there is only about 5-10% of my CPU in use. The other 95-90% is idle.
    – Dean
    Commented Oct 4, 2011 at 1:21
  • The simplest solution is to schedule an appointment at an Apple Store (not an authorized Apple service center). They'll run diagnostics on the battery and look into the matter. It could be that the battery is faulty. In any case, they'll be able to find the cause much quicker and easier.
    – user10355
    Commented Oct 4, 2011 at 1:27
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    I would also suggest against using an bloated app for note taking. Find the most light weight app you can, terminal and VI is a great option :) Commented Oct 4, 2011 at 2:36
  • @Lyken i need powerpoint open because we don't get handouts and is often difficult to see the projector.
    – Dean
    Commented Oct 4, 2011 at 10:19

2 Answers 2


Get a program like gfxCardStatus to monitor which graphics card is in use, and watch out for Flash or other processor-hungry apps in the background.

Everything @bmike said in his comment is correct, too.

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    Running microsoft messenger changes the graphics card for some strange reason :S so this could be true for all office applications.
    – Dean
    Commented Oct 4, 2011 at 1:31
  • @Dean gfxCardStatus can also be used to force the system to choose one of the cards. That may be worth a try.
    – Cajunluke
    Commented Oct 4, 2011 at 5:02
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    @Dean ACtually only Messenger does, none of the others do. Messenger supports video and switches. Also note that Chrome also switches the graphics card when downloading. On average with the NVidia card running I only get 4 hours, however using the built-in card I have used my Mac for 6 - 8 hours a day easily. Commented Oct 4, 2011 at 6:51

I would recommend performing a battery calibration. For various reasons, Macs tend to lose their ability the gauge the actual amount of battery charge remaining. Battery calibration re-teaches the system how to measure its battery life, sometimes making a significant difference. In any case, it's free to do, and is also good to do every now and again.

Your computer may be fairly new, but the battery could be many months old and may not have been stored or traveled in the most ideal of conditions (extreme heat, cold, moisture) on its way from the factory to you, which could have had an effect on its "calibration". This may or may not make a big difference for you, but it doesn't hurt to try.

Info for performing a battery calibration can be found at http://support.apple.com/kb/ht1490.

For your model, this would involve:

  1. Charging battery to 100%.

  2. Leaving computer on and awake, disconnect power.

  3. Keeping the computer on and awake, run down battery until computer shuts itself off. You can use the computer during this time.**

  4. After computer has gone to sleep, leave it alone for at least 5 hours (I usually leave it overnight.)

  5. Reconnected charger, and leave connected until fully charged.

**Caffiene is a great free program for overriding your Mac's power settings, and keeping it awake.

  • I shouldn't have to calibrate it after less than a month though.
    – Dean
    Commented Oct 5, 2011 at 16:29
  • You may have purchased the computer less than a month ago, but neither the computer nor the battery left the factory the day before. Keep in mind, all these Apple products we buy are shipped in containers across the Pacific, and as mentioned before, sometimes in a less than ideal environment. If you don't want to go through this process, you can at least get the iStat widget (islayer.com/apps/istatpro), which can tell you the state of health of your battery.
    – eee
    Commented Oct 6, 2011 at 3:10

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