Running laptop on AC power with battery removed

Discussion in 'Dell' started by starved@rock.com, Aug 13, 2009.

  1. Guest

    Brand new Dell Inspiron 1545 laptop purchased last week. At this time
    the system will be used as a desktop, running on AC power continously.

    According to http://www.batteryuniversity.com and other sources,
    leaving the battery in - while always running on AC power and never on
    battery power - will shorten the life of the battery.

    So the battery's been removed, and with a 40% charge on it, it's in a
    ziplock bag and stored in the refrigerator.

    The plan is to remove it from storage after some time, put it back in
    the laptop, recharge it back up to 40%, and then store it in the
    refrigerator again. This cycle will be repeated indefinitely.

    My questions are:

    1. How long can the battery remain stored in the refrigerator before
    it has to be recharged? One month? Two months?

    2. Should I be concerned about corrosion of the contacts or dust
    buildup in an empty battery compartment?

    Any help would be greatly appreciated. Thanks!

    - Dave
     
    , Aug 13, 2009
    #1
    1. Advertising

  2. BillW50 Guest

    In
    news:,
    typed on Thu, 13 Aug 2009 06:22:15 -0700 (PDT):
    > Brand new Dell Inspiron 1545 laptop purchased last week. At this time
    > the system will be used as a desktop, running on AC power continously.
    >
    > According to http://www.batteryuniversity.com and other sources,
    > leaving the battery in - while always running on AC power and never on
    > battery power - will shorten the life of the battery.
    >
    > So the battery's been removed, and with a 40% charge on it, it's in a
    > ziplock bag and stored in the refrigerator.
    >
    > The plan is to remove it from storage after some time, put it back in
    > the laptop, recharge it back up to 40%, and then store it in the
    > refrigerator again. This cycle will be repeated indefinitely.
    >
    > My questions are:
    >
    > 1. How long can the battery remain stored in the refrigerator before
    > it has to be recharged? One month? Two months?
    >
    > 2. Should I be concerned about corrosion of the contacts or dust
    > buildup in an empty battery compartment?
    >
    > Any help would be greatly appreciated. Thanks!


    You don't need to keep it in the refrigerator for one. I keep my dozen
    or so Li-Ion batteries in a drawer. While keeping the battery 40%
    charged figure is thrown around as being best, I use 80% to 90% range
    for storing and the batteries has lasted over 10 years this way.

    How often to recharge them? It depends on how much the internal
    resistance is. This varies from battery to battery. Typically most loses
    1% to 2% per month. So every 3, 6, or even 12 months should be okay.
    Pushing them 3 years in storage is where I find is often the trip point.
    As the voltage of the cells are close to or has exceeded the minimum
    safe levels and maybe too far gone by then.

    Contacts? I never had a problem with corrosion with the battery
    contacts.

    --
    Bill
    Gateway MX6124 ('06 era) - Windows XP SP2
     
    BillW50, Aug 13, 2009
    #2
    1. Advertising

  3. Guest

    On Aug 13, 9:04 am, "BillW50" <> wrote:
    > Innews:,
    > typed on Thu, 13 Aug 2009 06:22:15 -0700 (PDT):
    >
    >
    >
    >
    >
    > > Brand new Dell Inspiron 1545 laptop purchased last week. At this time
    > > the system will be used as a desktop, running on AC power continously.

    >
    > > According tohttp://www.batteryuniversity.comand other sources,
    > > leaving the battery in - while always running on AC power and never on
    > > battery power - will shorten the life of the battery.

    >
    > > So the battery's been removed, and with a 40% charge on it, it's in a
    > > ziplock bag and stored in the refrigerator.

    >
    > > The plan is to remove it from storage after some time, put it back in
    > > the laptop, recharge it back up to 40%, and then store it in the
    > > refrigerator again. This cycle will be repeated indefinitely.

    >
    > > My questions are:

    >
    > > 1. How long can the battery remain stored in the refrigerator before
    > > it has to be recharged? One month? Two months?

    >
    > > 2. Should I be concerned about corrosion of the contacts or dust
    > > buildup in an empty battery compartment?

    >
    > > Any help would be greatly appreciated. Thanks!

    >
    > You don't need to keep it in the refrigerator for one. I keep my dozen
    > or so Li-Ion batteries in a drawer. While keeping the battery 40%
    > charged figure is thrown around as being best, I use 80% to 90% range
    > for storing and the batteries has lasted over 10 years this way.
    >
    > How often to recharge them? It depends on how much the internal
    > resistance is. This varies from battery to battery. Typically most loses
    > 1% to 2% per month. So every 3, 6, or even 12 months should be okay.
    > Pushing them 3 years in storage is where I find is often the trip point.
    > As the voltage of the cells are close to or has exceeded the minimum
    > safe levels and maybe too far gone by then.
    >
    > Contacts? I never had a problem with corrosion with the battery
    > contacts.
    >
    > --
    > Bill
    > Gateway MX6124 ('06 era) - Windows XP SP2- Hide quoted text -
    >
    > - Show quoted text -


    Thanks for the responses.

    My plan is based on this information that I've found:

    http://laptopbatterynews.com/2009/04/15/how-can-you-maximize-your-laptops-battery-performance

    Remove Battery when Using AC/DC Power Source
    Laptop batteries are in constant charge and discharge state when you
    have the AC/DC adapter plugged into the computer and using the
    computer with the battery installed. Removing the battery while using
    the AC/DC adapter will help prolong the life span of the battey since
    most last 500-800 charging cycles or 18-24 months. These frequent
    shallow charges do not allow all of the battery cells to properly
    condition for optimum battery performance.

    http://www.batteryuniversity.com/partone-19.htm

    Keep batteries in a cool and dry storage area. Refrigeration is
    recommended but freezers should be avoided. When refrigerated, the
    battery should be placed in a plastic bag to protect against
    condensation

    Do not fully charge lithium and nickel-based batteries before storage.
    Keep them partially charged and apply a full charge before use. Store
    lithium-ion at about 40% state-of-charge (3.75-3.80V/cell open
    terminal). Lead-acid batteries must be stored fully charged.
     
    , Aug 13, 2009
    #3
  4. Buffalo Guest

    Meat Plow wrote:
    > On Thu, 13 Aug 2009 06:22:15 -0700 (PDT), te:
    >
    >> Brand new Dell Inspiron 1545 laptop purchased last week. At this time
    >> the system will be used as a desktop, running on AC power
    >> continously.
    >>
    >> According to http://www.batteryuniversity.com and other sources,
    >> leaving the battery in - while always running on AC power and never
    >> on battery power - will shorten the life of the battery.
    >>
    >> So the battery's been removed, and with a 40% charge on it, it's in a
    >> ziplock bag and stored in the refrigerator.
    >>
    >> The plan is to remove it from storage after some time, put it back in
    >> the laptop, recharge it back up to 40%, and then store it in the
    >> refrigerator again. This cycle will be repeated indefinitely.
    >>
    >> My questions are:
    >>
    >> 1. How long can the battery remain stored in the refrigerator before
    >> it has to be recharged? One month? Two months?
    >>
    >> 2. Should I be concerned about corrosion of the contacts or dust
    >> buildup in an empty battery compartment?
    >>
    >> Any help would be greatly appreciated. Thanks!
    >>
    >> - Dave

    >
    > Lithium Ion batteries have a finite number of charges. Has nothing to
    > do with leaving it in the laptop while on AC provided the power
    > functions of the laptop work as designed.


    From the link the OP supplied:

    "Storage in a cool place slows the aging process of lithium-ion (and other
    chemistries). Manufacturers recommend storage temperatures of 15°C (59°F).
    In addition, the battery should be partially charged during storage. The
    manufacturer recommends a 40% charge."

    "Lithium-ion offers good charging performance at cold and hot temperatures.
    The acceptable charge range is 0° to 45°C (32°F to 113°F). It is
    recommended, however, to reduce the charge rate to less than 1C at
    temperatures of 5°C to 0°C (41°F to 32°F).
    It is important to know that consumer grade lithium-ion batteries cannot be
    charged below 0°C (32°F). Although the packs appear to be charging normally
    at freezing temperatures, the cell impedance goes up and the acceptance of
    the ions on the anode is drastically reduced."

    " Quality chargers reduce the charge current at cold temperatures and avert
    a charge altogether below 0°C (32°F). When charging a cold battery, allow
    the pack to warm up before putting it into the charger. Discharging a
    lithium-ion battery at cold temperature does not cause any harm. The lower
    performance will only be noticeable while the pack is dwelling in the cold
    state."

    " The recommended storage temperature for most batteries is 15°C (59°F).
    While lead-acid batteries must always be kept at full charge, nickel and
    lithium-based chemistries should be stored at 40% state-of-charge (SoC)."

    "Lithium-ion powers most of today's laptop computers. The battery
    compartment on many laptops rises to about 45°C (113°F) during operation.
    The combination of high charge level and elevated ambient temperature
    presents an unfavorable condition for the battery. This explains the short
    lifespan of many laptop batteries."

    Buffalo
     
    Buffalo, Aug 13, 2009
    #4
  5. Happy Oyster Guest

    On Thu, 13 Aug 2009 06:22:15 -0700 (PDT), wrote:

    >Brand new Dell Inspiron 1545 laptop purchased last week. At this time
    >the system will be used as a desktop, running on AC power continously.
    >
    >According to http://www.batteryuniversity.com and other sources,
    >leaving the battery in - while always running on AC power and never on
    >battery power - will shorten the life of the battery.
    >
    >So the battery's been removed, and with a 40% charge on it, it's in a
    >ziplock bag and stored in the refrigerator.



    HELLO, NO! Not in the fridge!!!

    You have to look at the optimum storage temprature. That - so my guess - is
    somewhere between 14 to 20 °C

    Also, I would have loaded it fully before taking it into storage.


    >The plan is to remove it from storage after some time, put it back in
    >the laptop, recharge it back up to 40%, and then store it in the
    >refrigerator again. This cycle will be repeated indefinitely.


    No, all the time up to at leat 90 percent!


    >My questions are:
    >
    >1. How long can the battery remain stored in the refrigerator before
    >it has to be recharged? One month? Two months?


    In the cold it degrades fast.


    >2. Should I be concerned about corrosion of the contacts or dust
    >buildup in an empty battery compartment?


    YES! It must be a DRY place.

    --
    **** WARNING **** The web-hoster Globat.com steals money from your
    credit card account. If you are a customer of Globat.com, never give
    them any credit card information. If you can't erase the information,
    then do delete the old card and get a new one! **** WARNING ****
     
    Happy Oyster, Aug 13, 2009
    #5
  6. Buffalo Guest

    wrote:
    > Brand new Dell Inspiron 1545 laptop purchased last week. At this time
    > the system will be used as a desktop, running on AC power continously.
    >
    > According to http://www.batteryuniversity.com and other sources,
    > leaving the battery in - while always running on AC power and never on
    > battery power - will shorten the life of the battery.
    >
    > So the battery's been removed, and with a 40% charge on it, it's in a
    > ziplock bag and stored in the refrigerator.
    >
    > The plan is to remove it from storage after some time, put it back in
    > the laptop, recharge it back up to 40%, and then store it in the
    > refrigerator again. This cycle will be repeated indefinitely.
    >
    > My questions are:
    >
    > 1. How long can the battery remain stored in the refrigerator before
    > it has to be recharged? One month? Two months?


    According to the article in the above posted link, it states that a
    Lithium-ion battery stored at 40% charge in a cool place will be able to
    recover 98% of its capacity after 1 year.
    If it is stored at 100% charge, it will be able to recover only 94% of its
    capacity after 1 year.
    If stored a 25C (around room temp, but much cooler than it would be in the
    laptop):
    40% charge = 96% after 1 yr
    100% charge = 80% after 1 yr
    If stored in the laptop (around 45C+) it would probably lose over 40% of its
    capacity after 1 yr or less; it would be at full charge most of the time it
    was in the laptop.



    > 2. Should I be concerned about corrosion of the contacts or dust
    > buildup in an empty battery compartment?
    >
    > Any help would be greatly appreciated. Thanks!
    >
    > - Dave


    I think you are doing the right thing to prolong the laptop battery.
    When you take it out of the fridge, leave it in the ziplock bag until it
    warms up and don't charge it until it is around room temp and there is no
    moisture on the battery or its contacts.
    Putting a cold object in a warm moist room will cause a lot of condensation
    to form on the cold object.
    Buffalo
     
    Buffalo, Aug 13, 2009
    #6
  7. Buffalo Guest

    Meat Plow wrote:
    > On Thu, 13 Aug 2009 08:34:41 -0600, "Buffalo"
    > <>wrote:
    >
    >>
    >> Meat Plow wrote:
    >>> On Thu, 13 Aug 2009 06:22:15 -0700 (PDT), te:
    >>>
    >>>> Brand new Dell Inspiron 1545 laptop purchased last week. At this
    >>>> time the system will be used as a desktop, running on AC power
    >>>> continously.
    >>>>
    >>>> According to http://www.batteryuniversity.com and other sources,
    >>>> leaving the battery in - while always running on AC power and never
    >>>> on battery power - will shorten the life of the battery.
    >>>>
    >>>> So the battery's been removed, and with a 40% charge on it, it's
    >>>> in a ziplock bag and stored in the refrigerator.
    >>>>
    >>>> The plan is to remove it from storage after some time, put it back
    >>>> in the laptop, recharge it back up to 40%, and then store it in the
    >>>> refrigerator again. This cycle will be repeated indefinitely.
    >>>>
    >>>> My questions are:
    >>>>
    >>>> 1. How long can the battery remain stored in the refrigerator
    >>>> before it has to be recharged? One month? Two months?
    >>>>
    >>>> 2. Should I be concerned about corrosion of the contacts or dust
    >>>> buildup in an empty battery compartment?
    >>>>
    >>>> Any help would be greatly appreciated. Thanks!
    >>>>
    >>>> - Dave
    >>>
    >>> Lithium Ion batteries have a finite number of charges. Has nothing
    >>> to do with leaving it in the laptop while on AC provided the power
    >>> functions of the laptop work as designed.

    >>
    >> From the link the OP supplied:

    >
    > <snip>
    >
    > Doesn't apply to my experience, YMMV. Refrigeration may increase the
    > shelf life but the bottom line is still charge cycles.


    I agree with you on the charge cycles being finite and one of the limiting
    factors.
    Leaving it in the laptop subjects it to above room temps and shortens its
    ability to regain its capacity.
    The chart on the link posted by Dave was pretty enlightening.
    Buffalo
     
    Buffalo, Aug 13, 2009
    #7
  8. BillW50 Guest

    In
    news:,
    typed on Thu, 13 Aug 2009 07:19:47 -0700 (PDT):
    > Thanks for the responses.
    >
    > My plan is based on this information that I've found:
    >
    > http://laptopbatterynews.com/2009/04/15/how-can-you-maximize-your-laptops-battery-performance
    >
    > Remove Battery when Using AC/DC Power Source
    > Laptop batteries are in constant charge and discharge state when you
    > have the AC/DC adapter plugged into the computer and using the
    > computer with the battery installed. Removing the battery while using
    > the AC/DC adapter will help prolong the life span of the battey since
    > most last 500-800 charging cycles or 18-24 months. These frequent
    > shallow charges do not allow all of the battery cells to properly
    > condition for optimum battery performance.
    >
    > http://www.batteryuniversity.com/partone-19.htm
    >
    > Keep batteries in a cool and dry storage area. Refrigeration is
    > recommended but freezers should be avoided. When refrigerated, the
    > battery should be placed in a plastic bag to protect against
    > condensation
    >
    > Do not fully charge lithium and nickel-based batteries before storage.
    > Keep them partially charged and apply a full charge before use. Store
    > lithium-ion at about 40% state-of-charge (3.75-3.80V/cell open
    > terminal). Lead-acid batteries must be stored fully charged.


    I agree with most everything. Although that 500-800 recharges are
    partial recharges IMHO. As if you run them down all of the time before
    recharging, the number is usually within 200 to 250 range. And that 18
    to 24 month figure is true if left in the laptop. Not true if left out
    of the laptop. As it will last 3 or more times longer than that.

    The reason being is that the heat from the laptop (some are cooler than
    others) keeps the battery at higher temperatures. Which in the short run
    doesn't mean much. But day after day does degrade the battery which
    makes it useless in about 18 to 24 months for most laptops.

    Another side effect of leaving the battery in all of the time on AC, is
    that most laptops will recharge the battery again once it drops down to
    96%. So the battery will be in this 96% to 100% charged state the whole
    time it is left in the laptop on AC. Also not so good for the battery.

    And this last reason why not to leave it in the laptop which I am pretty
    much alone with this opinion. Is that laptop manufactures want to boost
    long battery life. And to do this, they charge the cells to 4.2v per
    cell. Great for longer running times. Bad for battery longevity. As
    stopping the charge when the battery hits 4.1v per cell makes it lasts
    so much longer IMHO.

    So there you go and good luck!

    --
    Bill
    Gateway MX6124 ('06 era) - Windows XP SP2
     
    BillW50, Aug 13, 2009
    #8
  9. iws Guest

    <> wrote in message
    news:...
    | Brand new Dell Inspiron 1545 laptop purchased last week. At this time
    | the system will be used as a desktop, running on AC power continously.
    |
    | According to http://www.batteryuniversity.com and other sources,
    | leaving the battery in - while always running on AC power and never on
    | battery power - will shorten the life of the battery.
    |
    | So the battery's been removed, and with a 40% charge on it, it's in a
    | ziplock bag and stored in the refrigerator.
    |
    | The plan is to remove it from storage after some time, put it back in
    | the laptop, recharge it back up to 40%, and then store it in the
    | refrigerator again. This cycle will be repeated indefinitely.
    |
    | My questions are:
    |
    | 1. How long can the battery remain stored in the refrigerator before
    | it has to be recharged? One month? Two months?
    |
    | 2. Should I be concerned about corrosion of the contacts or dust
    | buildup in an empty battery compartment?
    |
    | Any help would be greatly appreciated. Thanks!
    |
    | - Dave

    If you remove the battery while on AC, make sure you use a UPS to avoid
    unexpected power loss and data loss/corruption. Frankly, I would not keep a
    battery at 40% charge because then I'm screwed if I have to use the laptop
    on battery power on short notice without time to fully charge it. I've found
    that my laptop batteries typically last longer than two years albeit with a
    somewhat reduced capacity. But then I don't use my laptop as a desktop
    substitute. If I get 2-3 years of useful life without all fuss of storing
    half charged batteries, then I'm happy. After all, the cost of a new $100
    battery amortized over three years is $0.09 a day.
     
    iws, Aug 13, 2009
    #9
  10. chuckcar Guest

    wrote in
    news::

    > On Aug 13, 9:04 am, "BillW50" <> wrote:
    >> Innews:
    >> , typed on Thu, 13 Aug 2009 06:22:15 -0700 (PDT):


    > http://www.batteryuniversity.com/partone-19.htm
    >
    > Keep batteries in a cool and dry storage area. Refrigeration is
    > recommended but freezers should be avoided. When refrigerated, the
    > battery should be placed in a plastic bag to protect against
    > condensation
    >

    Wouldn't the water condense out of the air in the bag? Evacuating the bag
    in some way would seem prudent if possible even if just with a straw.


    --
    (setq (chuck nil) car(chuck) )
     
    chuckcar, Aug 13, 2009
    #10
  11. M.L. Guest


    >If you remove the battery, might be wise to run it on a UPS in case of
    >a surge or outage.


    That's exactly what I do, and it has come in handy.
     
    M.L., Aug 13, 2009
    #11
  12. Removing the battery IS a good idea.

    Storage in the refrigerator is really questionable, in my view. First,
    in a ziploc bag, you could have a humidity problem (and, in the case of
    Lithium batteries, that could be catastrophically bad). Second, if the
    battery happens to freeze, it can also be ruined. It is THEORETICALLY
    true that life is extended at lower temperatures as long as you don't go
    below freezing. However, as a practical matter, as long as you are
    dealing with the refrigerator vs. an air conditioned environment that
    never gets above about the high 70's .... I don't think that there is
    much PRACTICAL benefit.

    The battery should be given some use 3 to 6 times a year. What I'd do
    is charge it to 100%, then run it down to a mid-charge value. 40% may
    be a tad on the low side, but 40% to 60% is about right (again, while
    this is accepted best practice in theory, I'm not sure that the
    differnece between storing at full charge vs. mid charge is all that
    great (it's probably more than the difference between room temp. &
    refrigeration, however).

    You should not have to worry about either dust or corrosion.

    FWIW, I have 14 old year old batteries here, stored at 100% charge and
    room temperature, that still give good service. But it is absolutely
    true that with MOST laptops, leaving it in a laptop that is plugged in
    all the time will destroy the battery in 6 to 24 months. The culprits
    can be a combination of both overcharging and overheating (heat
    generated by other parts of the laptop), and both of these are design
    dependent, and, therefore, model dependent. But best practice is to
    remove the battery.

    That said, if you do remove the battery, get a small UPS. For a laptop,
    even a 300va UPS is adequate, and those can usually be had for $20-$30.



    wrote:
    > Brand new Dell Inspiron 1545 laptop purchased last week. At this time
    > the system will be used as a desktop, running on AC power continously.
    >
    > According to http://www.batteryuniversity.com and other sources,
    > leaving the battery in - while always running on AC power and never on
    > battery power - will shorten the life of the battery.
    >
    > So the battery's been removed, and with a 40% charge on it, it's in a
    > ziplock bag and stored in the refrigerator.
    >
    > The plan is to remove it from storage after some time, put it back in
    > the laptop, recharge it back up to 40%, and then store it in the
    > refrigerator again. This cycle will be repeated indefinitely.
    >
    > My questions are:
    >
    > 1. How long can the battery remain stored in the refrigerator before
    > it has to be recharged? One month? Two months?
    >
    > 2. Should I be concerned about corrosion of the contacts or dust
    > buildup in an empty battery compartment?
    >
    > Any help would be greatly appreciated. Thanks!
    >
    > - Dave
     
    Barry Watzman, Aug 13, 2009
    #12
  13. Meat Plow wrote:

    >
    > Lithium Ion batteries have a finite number of charges. Has nothing to
    > do with leaving it in the laptop while on AC provided the power
    > functions of the laptop work as designed.
     
    Barry Watzman, Aug 13, 2009
    #13
  14. You are wrong on the 2nd part. Leaving a battery in a laptop run
    continually on AC power generally destroys the battery.


    Meat Plow wrote:

    >
    > Lithium Ion batteries have a finite number of charges. Has nothing to
    > do with leaving it in the laptop while on AC provided the power
    > functions of the laptop work as designed.
     
    Barry Watzman, Aug 13, 2009
    #14
  15. Hi!

    > Brand new Dell Inspiron 1545 laptop purchased last week. At this
    > time the system will be used as a desktop, running on AC power
    > continously.


    I'm sure there was a reason, so I'm only asking out of curiosity. Why
    was a laptop purchased for this application?

    Letting the system run on AC power with the battery in all the time
    does two things:

    1. It fries the battery. The charging circuit is never off, instead it
    is always trickle charging. This slowly overcharges the cells and
    damages them.

    2. It puts the battery's onboard controller into an out-of-calibration
    state...so that even if you don't fry the cells, the battery may
    report a state of charge that doesn't match reality.

    > So the battery's been removed, and with a 40% charge on it, it's
    > in a ziplock bag and stored in the refrigerator.


    You don't need to do that. If the room you are in is comfortable, so
    too is the battery.

    As far as the state of charge when it's in storage, I've heard
    something said about the 40% marker before. I don't remember exactly
    what it was. And I've had fine results from storing fully charged
    batteries for a long time--outside of the occasional need to run them
    down and bring them up to put the controller back into calibration.

    I'd suggest using the battery every month or so, at least for a little
    while.

    The only thing to worry about with the battery compartment is anything
    conductive shorting the terminals inside. This might cause damage to
    the charging or DC-DC converter circuit.

    William
     
    William R. Walsh, Aug 13, 2009
    #15
  16. Linea Recta Guest

    "Meat Plow" <> schreef in bericht
    news:...
    > On Thu, 13 Aug 2009 08:34:41 -0600, "Buffalo"
    > <>wrote:
    >
    >>
    >>Meat Plow wrote:
    >>> On Thu, 13 Aug 2009 06:22:15 -0700 (PDT), te:
    >>>
    >>>> Brand new Dell Inspiron 1545 laptop purchased last week. At this time
    >>>> the system will be used as a desktop, running on AC power
    >>>> continously.
    >>>>
    >>>> According to http://www.batteryuniversity.com and other sources,
    >>>> leaving the battery in - while always running on AC power and never
    >>>> on battery power - will shorten the life of the battery.
    >>>>
    >>>> So the battery's been removed, and with a 40% charge on it, it's in a
    >>>> ziplock bag and stored in the refrigerator.
    >>>>
    >>>> The plan is to remove it from storage after some time, put it back in
    >>>> the laptop, recharge it back up to 40%, and then store it in the
    >>>> refrigerator again. This cycle will be repeated indefinitely.
    >>>>
    >>>> My questions are:
    >>>>
    >>>> 1. How long can the battery remain stored in the refrigerator before
    >>>> it has to be recharged? One month? Two months?
    >>>>
    >>>> 2. Should I be concerned about corrosion of the contacts or dust
    >>>> buildup in an empty battery compartment?
    >>>>
    >>>> Any help would be greatly appreciated. Thanks!
    >>>>
    >>>> - Dave
    >>>
    >>> Lithium Ion batteries have a finite number of charges. Has nothing to
    >>> do with leaving it in the laptop while on AC provided the power
    >>> functions of the laptop work as designed.

    >>
    >>From the link the OP supplied:

    >
    > <snip>
    >
    > Doesn't apply to my experience, YMMV. Refrigeration may increase the
    > shelf life but the bottom line is still charge cycles.



    Taking out battery = less charge cycles.



    --
    regards,

    |\ /|
    | \/ |@rk
    \../
    \/os
     
    Linea Recta, Aug 13, 2009
    #16
  17. Guest

    On Aug 13, 12:14 pm, "Christopher Muto" <> wrote:
    > no crossposting please.  this reply only to alt.sys.pc-clone.dell whereit
    > was read.
    >
    > first of all i wonder if you are aware of how dated (old) the informationis
    > on the web site that you referenced.
    > it talks about really old types of battery technology that have not been
    > shipped with new computers from any manufacturer in years.
    > a battery in a zip lock bag kept in your fridge isn't going to help you if
    > you plan on using your laptop like a laptop.  and if you are using your
    > laptop as a desktop (plugged into the wall) there is always the chance of
    > pulling the power cord out when the unit (or the cord) is moved... and
    > without a battery installed in the machine that means you loose whatever you
    > happen to be working on.  not using your battery also has a cost.  simply
    > put, a battery is not like fine wine, it does not get better when left ona
    > shelf to age.  use it or loose it.  what you spend on zip lock bags and in
    > time juggling the battery in and out of the system and not having it charged
    > when you actually need it will probably cost more in dollars and
    > productivity than a replacement battery will cost you when you happen to
    > need it.
    >
    > <> wrote in message
    >
    > news:...
    >
    >
    >
    > > Brand new Dell Inspiron 1545 laptop purchased last week. At this time
    > > the system will be used as a desktop, running on AC power continously.

    >
    > > According tohttp://www.batteryuniversity.comand other sources,
    > > leaving the battery in - while always running on AC power and never on
    > > battery power - will shorten the life of the battery.

    >
    > > So the battery's been removed, and with a 40% charge on it, it's in a
    > > ziplock bag and stored in the refrigerator.

    >
    > > The plan is to remove it from storage after some time, put it back in
    > > the laptop, recharge it back up to 40%, and then store it in the
    > > refrigerator again. This cycle will be repeated indefinitely.

    >
    > > My questions are:

    >
    > > 1. How long can the battery remain stored in the refrigerator before
    > > it has to be recharged? One month? Two months?

    >
    > > 2. Should I be concerned about corrosion of the contacts or dust
    > > buildup in an empty battery compartment?

    >
    > > Any help would be greatly appreciated. Thanks!

    >
    > > - Dave- Hide quoted text -

    >
    > - Show quoted text -


    I can see there are differences in opinion on this topic. I appreciate
    all who provided intelligent responses.

    After careful consideration, I'm going to go with Barry Watzman's
    advice.

    - The battery will be stored at 60% state of charge.

    - Instead of storing it in a refrigerator, it will be placed in a
    drawer, in an air conditioned environment that never gets above about
    the high 70's.

    - The battery will be given some use 4 times a year. Every 3 months
    it'll be charged it to 100%, then run down to 60%, then removed and
    put back in storage.

    Thanks again!

    - Dave
     
    , Aug 13, 2009
    #17
  18. ~misfit~ Guest

    Somewhere on teh intarwebs Meat Plow wrote:
    > On Thu, 13 Aug 2009 08:52:46 -0600, "Buffalo"
    > <>wrote:
    >> Meat Plow wrote:
    >>> On Thu, 13 Aug 2009 08:34:41 -0600, "Buffalo"
    >>> <>wrote:
    >>>> Meat Plow wrote:
    >>>>> On Thu, 13 Aug 2009 06:22:15 -0700 (PDT), te:
    >>>>>
    >>>>>> Brand new Dell Inspiron 1545 laptop purchased last week. At this
    >>>>>> time the system will be used as a desktop, running on AC power
    >>>>>> continously.
    >>>>>>
    >>>>>> According to http://www.batteryuniversity.com and other sources,
    >>>>>> leaving the battery in - while always running on AC power and
    >>>>>> never on battery power - will shorten the life of the battery.
    >>>>>>
    >>>>>> So the battery's been removed, and with a 40% charge on it, it's
    >>>>>> in a ziplock bag and stored in the refrigerator.
    >>>>>>
    >>>>>> The plan is to remove it from storage after some time, put it
    >>>>>> back in the laptop, recharge it back up to 40%, and then store
    >>>>>> it in the refrigerator again. This cycle will be repeated
    >>>>>> indefinitely.
    >>>>>>
    >>>>>> My questions are:
    >>>>>>
    >>>>>> 1. How long can the battery remain stored in the refrigerator
    >>>>>> before it has to be recharged? One month? Two months?
    >>>>>>
    >>>>>> 2. Should I be concerned about corrosion of the contacts or dust
    >>>>>> buildup in an empty battery compartment?
    >>>>>>
    >>>>>> Any help would be greatly appreciated. Thanks!
    >>>>>>
    >>>>>> - Dave
    >>>>>
    >>>>> Lithium Ion batteries have a finite number of charges. Has nothing
    >>>>> to do with leaving it in the laptop while on AC provided the power
    >>>>> functions of the laptop work as designed.
    >>>>
    >>>> From the link the OP supplied:
    >>>
    >>> <snip>
    >>>
    >>> Doesn't apply to my experience, YMMV. Refrigeration may increase the
    >>> shelf life but the bottom line is still charge cycles.

    >>
    >> I agree with you on the charge cycles being finite and one of the
    >> limiting factors.
    >> Leaving it in the laptop subjects it to above room temps and
    >> shortens its ability to regain its capacity.
    >> The chart on the link posted by Dave was pretty enlightening.
    >> Buffalo
    >>

    >
    > Depends on where the battery is located. Don't assume all laptop
    > battery packs are mounted close to sources of heat.
    >
    > On my two laptops the battery pack is up front away from heat sources.
    > Both were new in 2004. Both still run 2 hours on a charge as they did
    > 5 years ago. Both have remained attached for their entire life so far
    > and show no appreciable decrease in capacity.
    >
    > There are plenty of arguments for and against removal while using as a
    > desktop. I'm for removal as long as it doesn't compromise the laptop's
    > physical well being like (but not limited to) allowing foreign objects
    > to infiltrate or interfering with the laptop's electronics.


    Not to mention cooling. If there are 'apertures' exposed by removing the
    battery then air could be drawn in there when the fan is running,
    effectively short-circuiting the 'cooling path' and allowing some components
    to get too hot.

    Luckilly for me my IBM/Lenovo T60 thinkPad (with an extended 9 cell battery)
    that I only use on mains has software that allows you to set the parameters
    for charging. (If not used as soon as charge drops to 95% then the battery
    is topped off and one more cycle is aded to the count.

    I have my battery set to only charge when it drops to 40% and then to stop
    charging at 60%. As this machine (2.16GHz C2D T7400, 15" 4:3 IPS screen, 3GB
    RAM, ATI X1400/128MB, 320GB 7200rpm HDD) is no low-powered glorified pocket
    calculator it does use some power. I get 3.5 hours on a full charge so
    figure that, if I need to take it with me without warning, I'll get between
    one and just over two hours depending on where the battery level is within
    my parameters. (I have a spare adapter in my laptop bag as well.) Also, I
    hope that the battery will last longer than if it were constantly being
    topped off from 95%.

    I have a few power outages here so, with that taken into consideration,
    would rather not run the machine batteryless. Having a battery is like
    having a built-in UPS.
    --
    Shaun.

    "Give a man a fire and he's warm for the day. But set fire to him and he's
    warm for the rest of his life." Terry Pratchet, 'Jingo'.
     
    ~misfit~, Aug 14, 2009
    #18
  19. The empirical evidence that leaving a battery in a laptop running off AC
    is overwhelming. About 4 years ago there was a thread on this board
    that went on for almost a year and involved thousands of posts, and as
    someone who repairs laptops, I can tell you that we see this constantly.
    Leave a battery in a laptop running on AC all the time, and you
    destroy the battery without ever having really used it in 6 to 24 months.

    The reasons, however, are not as clear.

    The two factors most often cited are overcharging and heat. While, in
    theory, a laptop should stop charging a battery once it's fully charged,
    in practice many of them don't ... they apply a constant "trickle"
    charge, that is harmful to the battery.

    The other factor is heat; simply put, a battery left in a laptop that is
    on AC all the time, and that is possibly running 8 to 24 hours per day,
    is exposed to heat. Not necessarily internal heat from overcharging
    (that can happen also) or even heat associated in any way with the
    battery or it's charger, but simply heat from the CPU, the hard drive,
    the memory and all of the other "stuff" that is inside a modern laptop.
    Anyone who has put a laptop on your lap knows that modern laptops get
    hot. And a battery in a modern laptop gets hot. And heat destroys
    lithium ion batteries (hence the suggestion to refrigerate them, but
    while theoretically valid, that may be practical overkill).

    Both of these ... the design of the charging circuit and the thermal
    design and layout of the laptop itself ... are model specific, so
    exceptions may exist (probably do, in fact). But as a general rule ...
    leaving a battery in a laptop being run all or essentially all of the
    time from AC power is a good way to destroy it.


    Linea Recta wrote:
    > "Meat Plow" <> schreef in bericht
    > news:...
    >> On Thu, 13 Aug 2009 08:34:41 -0600, "Buffalo"
    >> <>wrote:
    >>
    >> <snip>
    >>
    >> Doesn't apply to my experience, YMMV. Refrigeration may increase the
    >> shelf life but the bottom line is still charge cycles.

    >
    >
    > Taking out battery = less charge cycles.
    >
    >
    >
     
    Barry Watzman, Aug 14, 2009
    #19
  20. nsquare

    Joined:
    Dec 13, 2009
    Messages:
    2
    wht if i run on ac supply without ups?

    hey guys wanted to knw wht if i run the laptop on ac supply without the battery if i dont use a ups? wud it do any harms?
     
    nsquare, Dec 13, 2009
    #20
    1. Advertising

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

It takes just 2 minutes to sign up (and it's free!). Just click the sign up button to choose a username and then you can ask your own questions on the forum.
Similar Threads
  1. Doc
    Replies:
    12
    Views:
    5,048
    Adam Corolla
    Jun 27, 2006
  2. nomorespameventhoughthejapanesespamgivesmeachuckle

    IBM Thinkpad Laptop Removed CMOS Battery | Now Black Screen

    nomorespameventhoughthejapanesespamgivesmeachuckle, May 21, 2006, in forum: Laptops
    Replies:
    1
    Views:
    696
    Chris Hill
    May 22, 2006
  3. nomorespameventhoughthejapanesespamgivesmeachuckle

    IBM Thinkpad Laptop Removed CMOS Battery | Now Black Screen

    nomorespameventhoughthejapanesespamgivesmeachuckle, May 21, 2006, in forum: IBM Thinkpad
    Replies:
    0
    Views:
    891
    nomorespameventhoughthejapanesespamgivesmeachuckle
    May 21, 2006
  4. Replies:
    71
    Views:
    3,672
    M.I.5¾
    Sep 2, 2009
  5. Paul
    Replies:
    2
    Views:
    2,315
Loading...

Share This Page