1. This forum section is a read-only archive which contains old newsgroup posts. If you wish to post a query, please do so in one of our main forum sections (here). This way you will get a faster, better response from the members on Motherboard Point.

How to not charge the battery when the laptop is plugged in?

Discussion in 'Laptops' started by sp_nrc, Oct 19, 2006.

  1. sp_nrc

    sp_nrc Guest

    Hi,

    My mom recently got a computer and I have been helping her with it.

    I read in the instruction manual that you should never charge the
    battery for longer than the required time because if you keep charging
    the battery when it is full the battery will be damaged.

    When the computer is turned off and the power cord is connected the
    computer takes four hours to charge.

    When the computer is turned on and the power cord is connected the
    battery will take 12 hours to charnge.

    My questions is this: When the computer is connected to the power cord
    and the battery is full, won't the battery be damaged from over
    charging? Is there some way to stop the battery from charging when the
    power cord is plugged in? My dad think that we may have to remove the
    battery when we use the power cord to run the computer.

    Thanks for any help,
    Andrew
     
    sp_nrc, Oct 19, 2006
    #1
    1. Advertisements

  2. Re: "I read in the instruction manual that you should never charge the
    battery for longer than the required time because if you keep charging
    the battery when it is full the battery will be damaged."

    I have never seen that stated in a manual, and it should not be true ...
    but at some level, it is. We know that if you leave a battery in a
    laptop that is continually powered from AC, over time it will be
    damaged. But the damage is very slow and takes a LONG time to occur (6
    months to 2 years). It's not normally a problem in terms of casual use.
    There should be no problem leaving a battery in for days or weeks at a
    time, but if the laptop is always plugged in, then you are better off
    removing the battery, or it will be damaged (very, very slowly, over
    months or years, not days or weeks).

    The charging behavior that you are seeing is normal. It should take
    longer (a lot longer) to charge when the laptop is turned on.

    The battery and/or the laptop has an internal circuit that essentially
    stops the charging when the battery is fully charged. However, there
    may continue to be a small "trickle charge" in some cases, and it is
    either the trickle charge or simply heat from other parts of the laptop
    that can slowly damage the battery.

    But the manufacturers, as far as I know, never tell you any of this,
    they tell you to keep the battery in the laptop constantly.

    The rule I'd recommend: If the laptop is going to be plugged in for
    days at a time (or longer, weeks, months), remove the battery. But if
    you are traveling and will truly be using the battery, just leave it in
    until the traveling is done.

    Also, consider getting a small, low-power UPS (say 300 to 400 VA) if you
    are using the laptop permanently plugged in with the battery removed.
    This should cost $30 or less (and sometimes these are on sale "free
    after rebate")
     
    Barry Watzman, Oct 19, 2006
    #2
    1. Advertisements

  3. sp_nrc

    ric Guest

    Some of the IBM Thinkpads do exactly this: they have
    (thinkpad-specific, unfortunately!) software that will offer to only
    charge the battery to, say, 96% if you tend to use it almost
    exclusivley on mains power, to better condition the battery.
    suspect this isn't practical via 3rd party software though..
    ric
     
    ric, Oct 19, 2006
    #3
    1. Advertisements

Ask a Question

Want to reply to this thread or ask your own question?

You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.