Resetting my laptop's battery?

Discussion in 'Dell' started by Bram Bos, Oct 10, 2003.

  1. Bram Bos

    Bram Bos Guest

    Hi all,

    I've just bought a second hand Dell Latitude CPi laptop,
    with a battery that gives up after a very short time. I've
    been told that there are programs out there that can "reset"
    a battery. How does it work? Can anyone shed some light on this?

    Cheers & thanks from Amsterdam,

    Bram
    Bram Bos, Oct 10, 2003
    #1
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  2. Bram Bos

    Leszek P. Guest

    Well, it's not so good as it sounds.
    Resetting battery is nothing more than maximal battery discharge
    and after that maximal charge. Sometimes this can help, mainly
    if your laptop battery hasn't been fully discharged for a long time.
    You can do this without any additional software, just turn off
    suspending on critical battery level and let your laptop to discharge
    the battery.

    cheers,

    Leszek


    Uzytkownik "Bram Bos" <> napisal w wiadomosci
    news:...
    > Hi all,
    >
    > I've just bought a second hand Dell Latitude CPi laptop,
    > with a battery that gives up after a very short time. I've
    > been told that there are programs out there that can "reset"
    > a battery. How does it work? Can anyone shed some light on this?
    >
    > Cheers & thanks from Amsterdam,
    >
    > Bram
    Leszek P., Oct 10, 2003
    #2
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  3. Bram Bos

    Gary Tait Guest

    Whereas On 10 Oct 2003 05:34:02 -0700, (Bram Bos)
    scribbled:
    , I thus relpy:
    >Hi all,
    >
    >I've just bought a second hand Dell Latitude CPi laptop,
    >with a battery that gives up after a very short time. I've
    >been told that there are programs out there that can "reset"
    >a battery. How does it work? Can anyone shed some light on this?
    >
    >Cheers & thanks from Amsterdam,
    >
    >Bram


    http://sweb.cz/Frantisek.Rysanek/battery.html

    See if that works.
    --
    Gary J. Tait . Email is at yahoo.com ; ID:classicsat
    Gary Tait, Oct 10, 2003
    #3
  4. Bram Bos

    Tumbleweed Guest

    "Bram Bos" <> wrote in message
    news:...
    > Hi all,
    >
    > I've just bought a second hand Dell Latitude CPi laptop,
    > with a battery that gives up after a very short time. I've
    > been told that there are programs out there that can "reset"
    > a battery. How does it work? Can anyone shed some light on this?
    >

    IME batteries dont last that long, especially if not maintained properly.
    Buy another one is probably best thing to do.

    --
    Tumbleweed

    Remove theobvious before replying (but no email reply necessary to
    newsgroups)
    Tumbleweed, Oct 10, 2003
    #4
  5. "Tumbleweed" <> wrote:

    >"Bram Bos" <> wrote in message


    >> I've just bought a second hand Dell Latitude CPi laptop,
    >> with a battery that gives up after a very short time. I've
    >> been told that there are programs out there that can "reset"
    >> a battery. How does it work? Can anyone shed some light on this?


    >IME batteries dont last that long, especially if not maintained properly.
    >Buy another one is probably best thing to do.


    *Not* IME direct, since I've never had a laptop, but from what has
    been posted over the years here AIUI laptop batteries tend to get
    tired and give up their life after a couple-three years. Given that
    the OP's laptop was second-hand, and unless he knew it had a
    new/recent battery replacement, it could very well just need a new
    battery.

    The price you pay for buying another person's computer, or anything
    second-handed, is that you inherit whatever problems made it a
    candidate for sale. If you know the seller, fine. Buying blind,
    caveat emptor, as always, applies.
    --
    OJ III
    [Email sent to Yahoo addy is burned before reading.
    Lower and crunch the sig and you'll net me at comcast]
    Ogden Johnson III, Oct 11, 2003
    #5
  6. Bram Bos

    jamie Guest

    Bram Bos <> wrote:
    > Hi all,
    >
    > I've just bought a second hand Dell Latitude CPi laptop,
    > with a battery that gives up after a very short time. I've
    > been told that there are programs out there that can "reset"
    > a battery. How does it work? Can anyone shed some light on this?


    I'm pretty sure the utility that Dell offered for "recalibrating"
    batteries was only for some models older than the CPi. Dell
    batteries are only warrantied for one year, although they will
    sometimes last a good deal longer before they fail to hold a charge.

    Most likely, you just need a new battery, although it could be a
    problem with the connectors or the motherboard.

    --
    jamie ()

    "There's a seeker born every minute."
    jamie, Oct 11, 2003
    #6
  7. Bram Bos

    Bram Guest

    In comp.sys.laptops, Ogden Johnson III <> wasted
    keystrokes on the following:

    >"Tumbleweed" <> wrote:


    >The price you pay for buying another person's computer, or anything
    >second-handed, is that you inherit whatever problems made it a
    >candidate for sale. If you know the seller, fine. Buying blind,
    >caveat emptor, as always, applies.


    I knew beforehand that the battery didn't perform too well anymore and
    the price was lowered accordingly. I was just curious about the
    existence of this reset-functionality, but I do expect I'll have to
    buy a new battery for on-the-road (though I'll mostly have the laptop
    plugged into the mains).


    --

    Remove internal organs to send me spam.
    But why bother? I don't check this account anyway.
    Bram, Oct 11, 2003
    #7
  8. Bram Bos

    David B. Guest

    There is no magic program to reset a bad battery, when it's bad, it's bad, period.

    --


    ----------------------------------------------------------------
    "Bram" <> wrote in message news:...
    > In comp.sys.laptops, Ogden Johnson III <> wasted
    > keystrokes on the following:
    >
    > >"Tumbleweed" <> wrote:

    >
    > >The price you pay for buying another person's computer, or anything
    > >second-handed, is that you inherit whatever problems made it a
    > >candidate for sale. If you know the seller, fine. Buying blind,
    > >caveat emptor, as always, applies.

    >
    > I knew beforehand that the battery didn't perform too well anymore and
    > the price was lowered accordingly. I was just curious about the
    > existence of this reset-functionality, but I do expect I'll have to
    > buy a new battery for on-the-road (though I'll mostly have the laptop
    > plugged into the mains).
    >
    >
    > --
    >
    > Remove internal organs to send me spam.
    > But why bother? I don't check this account anyway.
    David B., Oct 15, 2003
    #8
  9. "David B." wrote:
    >
    > There is no magic program to reset a bad battery, when it's bad, it's bad, period.


    Hallelujah! Somebody with a brain!

    Larry
    Lawrence Glasser, Oct 15, 2003
    #9
  10. Bram Bos

    mike Guest

    David B. wrote:
    > There is no magic program to reset a bad battery, when it's bad, it's bad, period.
    >



    While I agree with what you say, it might give one the wrong impression.

    Sometimes GOOD batteries get out of sync with the battery gauge chip and
    ACT like they're bad.
    That CAN be fixed by resetting. I've done it. I know other people
    who've done it.

    Send me some "bad" batteries that fit HP660LX and Jornada 690.
    I don't think they're smart, I just need some plastic to re-cell.
    The duct tape keeps coming off ;-)
    mike


    --
    Bunch of stuff For Sale and Wanted at the link below.
    laptops and parts Test Equipment
    4in/400Wout ham linear amp.
    Honda CB-125S
    400cc Dirt Bike 2003 miles $550
    Police Scanner, Color LCD overhead projector
    Tek 2465 $800, ham radio, 30pS pulser
    Tektronix Concept Books, spot welding head...
    http://www.geocities.com/SiliconValley/Monitor/4710/
    mike, Oct 15, 2003
    #10
  11. Well, yes and no.

    If the battery cells are truly bad, then no software will reset any bad
    cells.

    BUT .... many batteries have an intelligent battery controller chip in
    them, quite often a BQ2092 or a BQ2040. These chips monitor the battery
    and control charging, their purpose is to prevent excessive temperature
    and overcharging, as lithium batteries can become dangerously explosive
    when improperly managed.

    Unfortunately, sometimes under a variety of circumstances, they can come
    to believe that the battery is bad (won't take a full charge) when it
    really isn't. However, their control over the internals of the battery
    and the individual cells is so complete that if they come to believe
    that the battery is bad (even when it's not), then they won't let you
    fully charge the battery.

    There are programs to reset these chips in these situations, but the
    process is really messy in most cases. Usually, you have to open up the
    battery, make a special cable to connect the battery controller PCB to
    the parallel port, and also open the circuit of the cells, to remove
    power from the battery controller (forcing it to reset itself).

    There have been detailed articles published on the net on how to do
    this, do a google search on BQ2092 and BQ2040. There are other battery
    controllers as well, and some laptops have the battery controller in the
    laptop rather than in the battery. Finally, as noted, if the cells
    really are bad, nothing is going to reset them, the description I've
    given describes a fairly special (although not all that uncommon) case.


    Lawrence Glasser wrote:

    > "David B." wrote:
    >
    >>There is no magic program to reset a bad battery, when it's bad, it's bad, period.

    >
    >
    > Hallelujah! Somebody with a brain!
    >
    > Larry
    Barry Watzman, Oct 16, 2003
    #11
  12. Well, yes and no.

    If the battery cells are truly bad, then no software will reset any bad
    cells.

    BUT .... many batteries have an intelligent battery controller chip in
    them, quite often a BQ2092 or a BQ2040. These chips monitor the battery
    and control charging, their purpose is to prevent excessive temperature
    and overcharging, as lithium batteries can become dangerously explosive
    when improperly managed.

    Unfortunately, sometimes under a variety of circumstances, they can come
    to believe that the battery is bad (won't take a full charge) when it
    really isn't. However, their control over the internals of the battery
    and the individual cells is so complete that if they come to believe
    that the battery is bad (even when it's not), then they won't let you
    fully charge the battery.

    There are programs to reset these chips in these situations, but the
    process is really messy in most cases. Usually, you have to open up the
    battery, make a special cable to connect the battery controller PCB to
    the parallel port, and also open the circuit of the cells, to remove
    power from the battery controller (forcing it to reset itself).

    There have been detailed articles published on the net on how to do
    this, do a google search on BQ2092 and BQ2040. There are other battery
    controllers as well, and some laptops have the battery controller in the
    laptop rather than in the battery. Finally, as noted, if the cells
    really are bad, nothing is going to reset them, the description I've
    given describes a fairly special (although not all that uncommon) case.


    Lawrence Glasser wrote:

    > "David B." wrote:
    >
    >>There is no magic program to reset a bad battery, when it's bad, it's bad, period.

    >
    >
    > Hallelujah! Somebody with a brain!
    >
    > Larry
    Barry Watzman, Oct 16, 2003
    #12
  13. Barry Watzman wrote:
    >
    > Well, yes and no.
    >
    > If the battery cells are truly bad, then no software will reset any bad
    > cells.
    >
    > BUT .... many batteries have an intelligent battery controller chip in
    > them, quite often a BQ2092 or a BQ2040. These chips monitor the battery
    > and control charging, their purpose is to prevent excessive temperature
    > and overcharging, as lithium batteries can become dangerously explosive
    > when improperly managed.
    >
    > <snip>


    Thank you for the education... Greatly appreciated!

    But, because of the age of Dell's CPi series, one would be lead to
    believe that the battery (Not "batteries," so this was probably the
    original owner's only one.) is just plain old.

    Is there any documentation as to what age, in the battery's life,
    these chips usually fail? Can it happen at any time? Does it happen,
    in reality, at any time, or does it usually show up, early, as a
    defective battery?

    Again, thanks!

    Larry
    Lawrence Glasser, Oct 16, 2003
    #13
  14. Bram Bos

    mike Guest

    Lawrence Glasser wrote:

    >
    > But, because of the age of Dell's CPi series, one would be lead to
    > believe that the battery (Not "batteries," so this was probably the
    > original owner's only one.) is just plain old.

    snip
    > Larry


    This is my serious pet peeve with web helpers...sweeping conclusions
    based on NO actual information for the specific case under discussion.
    While comments on AVERAGE situations can be useful, there's no
    substitute for suggestons pertinent to the UNIQUE situation at hand.
    mike

    --
    Bunch of stuff For Sale and Wanted at the link below.
    laptops and parts Test Equipment
    4in/400Wout ham linear amp.
    Honda CB-125S
    400cc Dirt Bike 2003 miles $550
    Police Scanner, Color LCD overhead projector
    Tek 2465 $800, ham radio, 30pS pulser
    Tektronix Concept Books, spot welding head...
    http://www.geocities.com/SiliconValley/Monitor/4710/
    mike, Oct 16, 2003
    #14
  15. Normally, the battery controller chips don't fail. And the situation
    that I described is not really a "failure", but rather case of the
    battery controller chip somehow getting false information or becoming
    "out of sync" with the actual status of the battery cells. It doesn't
    happen often, but it does happen "often enough".

    Properly treated, Lithium batteries can last the better part of a
    decade, I have a number of Toshiba 2487 laptop batteries from 1997 that
    are still going strong (and that battery model is still in production
    and use in current model Toshibas, although in it's latest incarnation,
    they have increased the rated capacity to 4500mah and on that model it's
    called a 3107 rather than a 2487, but it's really essentially the same
    battery.



    Lawrence Glasser wrote:

    > Barry Watzman wrote:
    >
    >>Well, yes and no.
    >>
    >>If the battery cells are truly bad, then no software will reset any bad
    >>cells.
    >>
    >>BUT .... many batteries have an intelligent battery controller chip in
    >>them, quite often a BQ2092 or a BQ2040. These chips monitor the battery
    >>and control charging, their purpose is to prevent excessive temperature
    >>and overcharging, as lithium batteries can become dangerously explosive
    >>when improperly managed.
    >>
    >><snip>

    >
    >
    > Thank you for the education... Greatly appreciated!
    >
    > But, because of the age of Dell's CPi series, one would be lead to
    > believe that the battery (Not "batteries," so this was probably the
    > original owner's only one.) is just plain old.
    >
    > Is there any documentation as to what age, in the battery's life,
    > these chips usually fail? Can it happen at any time? Does it happen,
    > in reality, at any time, or does it usually show up, early, as a
    > defective battery?
    >
    > Again, thanks!
    >
    > Larry
    Barry Watzman, Oct 16, 2003
    #15
  16. Barry Watzman wrote:
    >
    > Normally, the battery controller chips don't fail. And the situation
    > that I described is not really a "failure", but rather case of the
    > battery controller chip somehow getting false information or becoming
    > "out of sync" with the actual status of the battery cells. It doesn't
    > happen often, but it does happen "often enough".
    >
    > Properly treated, Lithium batteries can last the better part of a
    > decade, I have a number of Toshiba 2487 laptop batteries from 1997 that
    > are still going strong (and that battery model is still in production
    > and use in current model Toshibas, although in it's latest incarnation,
    > they have increased the rated capacity to 4500mah and on that model it's
    > called a 3107 rather than a 2487, but it's really essentially the same
    > battery.


    My understanding of lithium batteries is that they have a "limited"
    number of charging cycles available, before degradation. E.g., the
    number might be "200." The battery will accept 200 charges, whether
    or not it was depleted partially or completely before each charge.
    After that, it's all downhill.

    Long shelf life, no memory effect, just limited charges.

    Larry
    Lawrence Glasser, Oct 16, 2003
    #16
  17. That's basically correct, but the limit is not as "hard" as your post
    might be read to imply. By that I mean that the number of cycles that
    you varies widely from battery to battery, and that the loss of capacity
    with additional charge-discharge cycles is very gradual and is not a
    sharp "cliff" where the battery is good after 347 charge cycles and dead
    as a doorknob after the 348th cycle. The number of cycles depends on
    the exact history of the particular battery, the variable include age,
    temperature over it's entire life and both the number of
    charge/discharge cycles and also the nature of the cycles --
    low-current, high current, and so on. The typical range on the number
    of charge cycles that you get is probably a higher than your example
    figure of 200, but it's in the range of hundreds. The one point where
    I'd differ is that the effect of a full discharge-charge cycle is not
    the same as that of a partial cycle.

    For maximum life, keep the temperature down and don't "deep discharge"
    the battery, discharging it below about 25%-30% should be avoided if
    possible. Overcharging (continuing to charge after the battery is fully
    charged) is also a killer (in part because it produces unnecessary
    internal heating).



    Lawrence Glasser wrote:

    > Barry Watzman wrote:
    >
    >>Normally, the battery controller chips don't fail. And the situation
    >>that I described is not really a "failure", but rather case of the
    >>battery controller chip somehow getting false information or becoming
    >>"out of sync" with the actual status of the battery cells. It doesn't
    >>happen often, but it does happen "often enough".
    >>
    >>Properly treated, Lithium batteries can last the better part of a
    >>decade, I have a number of Toshiba 2487 laptop batteries from 1997 that
    >>are still going strong (and that battery model is still in production
    >>and use in current model Toshibas, although in it's latest incarnation,
    >>they have increased the rated capacity to 4500mah and on that model it's
    >>called a 3107 rather than a 2487, but it's really essentially the same
    >>battery.

    >
    >
    > My understanding of lithium batteries is that they have a "limited"
    > number of charging cycles available, before degradation. E.g., the
    > number might be "200." The battery will accept 200 charges, whether
    > or not it was depleted partially or completely before each charge.
    > After that, it's all downhill.
    >
    > Long shelf life, no memory effect, just limited charges.
    >
    > Larry
    Barry Watzman, Oct 16, 2003
    #17
  18. Barry Watzman wrote:
    >
    > That's basically correct, but the limit is not as "hard" as your post
    > might be read to imply. By that I mean that the number of cycles that
    > you varies widely from battery to battery, and that the loss of capacity
    > with additional charge-discharge cycles is very gradual and is not a
    > sharp "cliff" where the battery is good after 347 charge cycles and dead
    > as a doorknob after the 348th cycle. The number of cycles depends on
    > the exact history of the particular battery, the variable include age,
    > temperature over it's entire life and both the number of
    > charge/discharge cycles and also the nature of the cycles --
    > low-current, high current, and so on. The typical range on the number
    > of charge cycles that you get is probably a higher than your example
    > figure of 200, but it's in the range of hundreds. The one point where
    > I'd differ is that the effect of a full discharge-charge cycle is not
    > the same as that of a partial cycle.
    >
    > For maximum life, keep the temperature down and don't "deep discharge"
    > the battery, discharging it below about 25%-30% should be avoided if
    > possible. Overcharging (continuing to charge after the battery is fully
    > charged) is also a killer (in part because it produces unnecessary
    > internal heating).


    Once again, thanks for taking the time for the education!

    Larry
    Lawrence Glasser, Oct 16, 2003
    #18
  19. >> There is no magic program to reset a bad battery, when it's bad, it's
    >> bad, period.

    >
    > Sometimes GOOD batteries get out of sync with the battery gauge chip
    > and ACT like they're bad.
    >


    The battery controller (AKA the gas-gauge) hardly ever goes nuts all by itself.
    You'd have to accidentally short the terminals or something.
    More likely, there's something wrong with the cells, so that the pack sags
    under load - or the capacity is just gone due to age.
    Normally, resetting the battery makes sense only after replacing the cells.
    If there's a defective cell in the pack, it's not likely to self-heal.

    In this particular case (old battery), my guess is that the cells are just
    worn. If replacing the cells is not an option in your area, you need to
    get a whole new battery pack. If you manage to get the cells replaced,
    a reset of the pack's chip is due - caveat, not all gas gauge chips can
    be reset. With some, it may take quite some hacking, and with some
    of the newer chips it's just plain impossible (on-chip flash + write-protect lock).


    The gas gauge learns battery capacity upon full charge cycles (judged by
    voltage tresholds). It's more willing to re-learn down than up - e.g., it may
    be bounded to re-learn up by max. 20 per cent in a single charge cycle.
    It's usually also hard-wired to refuse to re-learn upward, once the last
    learned capacity reaches a particular "battery dead" lower bound, say
    25% of the design capacity.

    Thus, if you overload (or even short) the battery pack, you may make
    the gas gauge think that the battery cells are completely worn.
    That's where a reset may help.
    Also, if the cells really are worn and you manage to replace them, you have
    yet to reset the chip to remove the "battery dead" alarm status flag.

    I've noticed that, as the battery cells are ageing (collecting charge cycles),
    they start to tend to sag under load.
    Their equivalent internal series resistance is gradually growing. Thus, the
    battery is able to deliver its full capacity, but only over a longer period
    of discharge. The point is that the notebook drains the battery in two
    hours or so, which is quite fast. Thus, due to the current drain combined
    with the gradually growing series resistance, the battery controller's
    over-discharge alarm may fire even though the battery is not really
    empty. And the gas gauge re-learns to a lower capacity.

    The only solution is to replace the cells or buy a whole new battery.
    A reset may help temporarily, until on another occasion (disk activity
    peak or something) the cells sag once again.
    This problem may be getting worse as the cell manufacturers are
    trying to stuff ever more capacity into the space available - higher
    capacity often means higher series resistance and lower recommended
    current handling. Some manufacturers and battery models are known
    to perform better in this respect than others.

    Imagine that you get a brand new battery upgrade for your notebook,
    with nominal capacity 50% higher than the original - but the magic only
    lasts for a few months, then you get sudden shutdowns at "50% gas left
    in the tank..."
    Okay, seems like I've wandered off topic :)

    Frank Rysanek
    Frantisek Rysanek, Oct 17, 2003
    #19
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