11 Replies Latest reply: Sep 15, 2007 8:45 AM by First Magus
MichaelShor Level 1 Level 1 (0 points)
Currently I am at college, and for the most part my macbook spends most of its days perched on my desk spreading joy and cheer to the world. What I wanted to ask was what I should do regarding getting the most out of my future battery life? Right now I charge my macbook to 100%, unplug it, use it for however long until it drains, and then charge it again. Would it be better for the battery to instead let it charge to 100% and then keep it plugged into the adapter? Which is better: continuous charge/recharge cycles, or keeping the computer plugged into the wall at 100%? Thanks for the help.

macbook, Mac OS X (10.4.10)
  • a brody Level 9 Level 9 (64,210 points)
    Welcome to Apple Discussions!

    Well based on http://www.apple.com/batteries/ it suggests what you are doing is good. There are exceptions though. If you are using a lot of processor cycles during the battery use, those battery cycles will be shorter. If you don't have the battery inserted at all during those high processor cycle periods, you may actually get a longer life span on the battery. Of course if you had a sudden power failure during the time the battery was not inserted, and it wasn't ready to be inserted in 5 seconds, you might not only lose all your unsaved work, but damage your directory as well. Which is another reason why I always recommend backing up your data as my FAQ* explains:

    http://www.macmaps.com/backup.html

    That way if the directory does get damaged, you can repair it without damaging data you wanted to save.

    - * Links to my pages may give me compensation

    Message was edited by: a brody
  • First Magus Level 6 Level 6 (15,850 points)
    dementedsodacan wrote:
    Would it be better for the battery to instead let it charge to 100% and then keep it plugged into the adapter?


    This is best as long as you calibrate your battery. See tips below.

    Which is better: continuous charge/recharge cycles,


    This wastes battery life. Li-Ion does not need this and works best with small charges.

    or keeping the computer plugged into the wall at 100%? Thanks for the help.


    It is OK to leave your battery hooked to the charger most of the time. The only time I unhook mine from the charger is when I calibrate. You should calibrate your battery once a month.

    The following links have good information about the MacBook and the care of it's battery.

    MacBook reduces processor speed when battery is removed while operating from an A/C adaptor

    Apple portable computer's battery does not show a full charge in Mac OS X

    Apple Notebook Batteries

    Lithium-ion Batteries

    MacBook: How to remove or install the battery

    Determining Battery Cycle Count

    Use and cleaning of MagSafe power connector

    Look here for some good tips about battery care.

    Mort
  • jdrodgers85 Level 1 Level 1 (20 points)
    With regards to energy consumption/conservation, it would be better to charge the battery until full, and unplug the adapter from the wall socket until needed. Leaving plugs/adapters hooked to live sockets uses energy whether your appliances are on or off. Just a thought...
  • First Magus Level 6 Level 6 (15,850 points)
    jdrodgers85 wrote:
    With regards to energy consumption/conservation, it would be better to charge the battery until full, and unplug the adapter from the wall socket until needed. Leaving plugs/adapters hooked to live sockets uses energy whether your appliances are on or off. Just a thought...


    The only problem is the amount of money or energy used by leaving it plugged in would be less than having to fully charge the battery using it this way. It is much more energy efficient to leave the charger plugged in so that you don't waste energy charging it all the time once the battery runs down each time you unplug once full charge is achieved.

    Replacing the battery sooner because you are doing full charges every time when you would be better off leaving it plugged in until you really need to use the battery is not cost affective either.

    Mort
  • jdrodgers85 Level 1 Level 1 (20 points)
    First Magus wrote:
    It is much more energy efficient to leave the charger plugged in


    Whenever plugs/adapters are plugged into a live socket, energy is being consumed, whether or not the device in question needs charging or not; a socket does not magically increase voltage when devices need charging.

    First Magus wrote:
    Replacing the battery sooner because you are doing full charges every time when you would be better off leaving it plugged in until you really need to use the battery _is not cost affective_ either.


    As I said, 'With regards to energy consumption/conservation' not with regards to cost effectiveness. Though this student is at college so he is not paying an electricity bill, the monthly savings from unplugging all appliances when not in use would probably outweigh the cost of a new computer battery (an infrequent purchase either way).
  • First Magus Level 6 Level 6 (15,850 points)
    jdrodgers85 wrote:
    Whenever plugs/adapters are plugged into a live socket, energy is being consumed, whether or not the device in question needs charging or not; a socket does not magically increase voltage when devices need charging.


    A power adapter will use more power charging a battery than it will sitting idle with the battery at full charge. You are correct about voltage not magically increasing. The current does increase in the charge mode. This is basic electricity not magic. P=IE. (Power=Current times Voltage) Voltage is normally a constant when coming from a wall socket.

    jdrodgers85 wrote:
    As I said, 'With regards to energy consumption/conservation' not with regards to cost effectiveness. Though this student is at college so he is not paying an electricity bill, the monthly savings from unplugging all appliances when not in use would probably outweigh the cost of a new computer battery (an infrequent purchase either way).


    I was trying to point out that by unplugging the MacBook adapter every time you reach full charge and letting it run off battery till it needs charging again is not good energy consumption/conservation or cost effective. The amount of current (not voltage) needed to recharge the battery every time this happens is much more than the current that would be used by just letting the adapter stay plugged in while using your computer and keeping the battery at full charge. We did many tests where I worked concerning this. The same test can be done with a cheap power meter that can be plugged in at the wall socket between it and the adapter. This can tell you how much power is being consumed in different modes.

    Mort
  • eiztudn Level 1 Level 1 (0 points)
    Hi,

    I'm a new member here.

    Regarding about what dementedsodacan asked, when I use my macbook on desk I usually charge my battery until 100%, and then I SHUT THE COMPUTER DOWN, DETACH the battery, PLUG the macbook to the power outlet and TURN IT ON. I will attach the battery when I go commuting.
    Someone suggested this to me few months ago. What I would like to ask is: Is this the right thing to do?
    Please kindly help me with this.
  • First Magus Level 6 Level 6 (15,850 points)
    eiztudn wrote:
    Regarding about what dementedsodacan asked, when I use my macbook on desk I usually charge my battery until 100%, and then I SHUT THE COMPUTER DOWN, DETACH the battery, PLUG the macbook to the power outlet and TURN IT ON. I will attach the battery when I go commuting.
    Someone suggested this to me few months ago. What I would like to ask is: Is this the right thing to do?
    Please kindly help me with this.


    Read this in reference to removing the battery.

    MacBook reduces processor speed when battery is removed while operating from an A/C adaptor

    You do not need to do this as the MacBook is designed to work with the battery installed. Once the Battery gets fully charged the charging stops. The battery sits idle while you are using it plugged in.

    It is OK to leave your battery hooked to the charger most of the time. The only time I unhook mine from the charger is when I calibrate. You should calibrate your battery once a month.

    Check out the links in my earlier post for more info.

    Mort
  • eiztudn Level 1 Level 1 (0 points)
    Thanks for the help.

    And there's another question. I noticed on the battery that there are one small button and 5 small indicator lamps that turn to green if I push the button, what do they do? is there anything I should know about this button and indicators?

    Thanks in advance
  • First Magus Level 6 Level 6 (15,850 points)
    That lets you know the condition of the charge. It helps when you have a couple of batteries you swap out. You can check the charge while a battery isn't installed using the button. I never use this since I have one battery and it is always installed.

    Mort