Printed from

MacBooks slow down with battery removed

updated 04:00 pm EST, Fri November 21, 2008

MacBook Slow WO Battery

Apple's newer MacBook range continues to exhibit an unusual design behavior that slows the system down when the battery isn't attached, testing by Gearlog confirms. Although only publicized in a support article from August that predates the late 2008 refresh, the unibody systems deliberately throttle back the processor when relying only on AC power. The company argues that the move is necessary to protect the system from an unintended shutdown if the system demands more energy than a wall outlet can provide by itself.

In benchmarking, the slowdown is also steep, dropping a CINEBENCH R10 test on a 2.53GHz MacBook Pro from 5,549 points to 3,504. The difference leaves the system at just 63 percent of its original performance.

The trait is unusual for most PC makers, which often only engage in the common practice of scaling back the processor when on battery-only power to extend runtime. It also potentially complicates the long-term use of Apple's portables by triggering a slowdown should the battery die suddenly or at the end of its practical lifetime. Users would need to either have a functioning replacement battery or obtain a new system regardless of the state of the system itself.

By Electronista Staff
Post tools:




  1. Eldernorm

    Fresh-Faced Recruit

    Joined: Sep 2007


    More BS Apple stuff

    Boy, are the pundits hungry for anti apple stuff. :-)

    A laptop is a battery powered device, the ac is only intended as a recharge or to prevent the battery from draining. If you want an ac powered device I suggest you use a desk top.

    Just a thought.
    en :-)

  1. Guest

    Fresh-Faced Recruit

    Joined: Nov 1999



    The new Macbook requires more power than a standard wall outlet can provide? SERIOUSLY!?!

    Thats a LOT of juice. But I bet it will be a great sack warmer.

  1. Guest

    Fresh-Faced Recruit

    Joined: Nov 1999



    "by triggering a slowdown should the battery die suddenly or at the end of its practical lifetime."

    My understanding of this issue is that its only if the MacBook senses the battery is not physically installed, not if the battery is installed but totally uncharged/dead. Is that not the case?

  1. lkrupp

    Junior Member

    Joined: May 2001



    Is there a valid reason someone would operate their MacBook without a battery installed. I said "valid" not "just because".

  1. martinX

    Fresh-Faced Recruit

    Joined: Sep 2008


    20 amp wall outlet.

    My wall outlets can supply 20 amps, which at our voltage is (theoretically) 4800 watts. Perhaps they mean the battery is used to smooth out any sharp fluctuations on the supply side and the demand side.

  1. dliup

    Fresh-Faced Recruit

    Joined: Jan 2006



    All recent macs laptops are like that for years, not specific to that model.

  1. JuanGuapo

    Fresh-Faced Recruit

    Joined: Jan 2008


    This is news?

    All Macs have done this since they switched to Intel....must be a slow news day.

  1. DeepBlade

    Fresh-Faced Recruit

    Joined: Nov 2008


    This is news, how??????

    err.. I thought we all knew this already.. My 2nd gen BlackBook does this.. what's the big deal?

  1. ggirton

    Fresh-Faced Recruit

    Joined: Nov 1999


    whoa i didnt know!

    i'm takin' out my battery right away to check this one out; this is important news!

  1. euclid

    Fresh-Faced Recruit

    Joined: Jul 2008


    obtain a new system?!?!

    "Users would need to either have a functioning replacement battery or obtain a new system regardless of the state of the system itself."

    Somebody want to explain to me how a battery at the end of its life would require me to buy a new system?

Login Here

Not a member of the MacNN forums? Register now for free.


Network Headlines


Most Popular


Recent Reviews

Apple 13-inch MacBook Pro (Early 2015)

Although the new darling of the Apple MacBook line up is the all-new MacBook, Apple has given its popular 13-inch MacBook Pro with Ret ...

Seagate Wireless

It seems like no matter how much internal storage is included today's mobile devices, we, as users, will always find a way to fill the ...

Lenovo Yoga Tablet 2 (Android, 10.1-inch)

Lenovo is building a bigger name for itself year after year, including its devices expanding beyond desktop computers. The company's l ...



Most Commented


Popular News