In the past I have replaced the CMOS power cell of my PC, but I was
wondering how is this done in a laptop? Is the cell accessible at all?



--
regards,

|\ /|
| \/ |@rk
\../
\/os

On Sun, 20 Sep 2009 15:43:35 +0200, "Linea Recta" <mccm.vos@abc.invalid> wrote:

>In the past I have replaced the CMOS power cell of my PC, but I was
>wondering how is this done in a laptop? Is the cell accessible at all?

What does your PCB say?
--
"Syrer besetzten die Städte,
frevelten dort um die Wette.
Wollten von Jahwe nichts wissen,
wurden von Löwen zerrissen." http://www.reimbibel.de

In news:4ab6318a$0$83248$e4fe514c@news.xs4all.nl,
Linea Recta typed on Sun, 20 Sep 2009 15:43:35 +0200:
> In the past I have replaced the CMOS power cell of my PC, but I was
> wondering how is this done in a laptop? Is the cell accessible at all?

Most laptops and netbooks use Ni-HM batteries for the CMOS/RTC which the
computer routinely recharges. They rarely fail so I wouldn't worry too
much about them. I would worry more about the florescent lamp, inverter,
hard drive, and main battery myself. Although if you are still
interested, it usually requires total disassembly to get to it.

--
Bill
Windows 2000 SP4 (5.00.2195)
Asus EEE PC 701G4 ~ 2GB RAM ~ 16GB-SDHC

"BillW50" <BillW50@aol.kom> schreef in bericht
news:h95ed7$es$1@news.eternal-september.org...
> In news:4ab6318a$0$83248$e4fe514c@news.xs4all.nl,
> Linea Recta typed on Sun, 20 Sep 2009 15:43:35 +0200:
>> In the past I have replaced the CMOS power cell of my PC, but I was
>> wondering how is this done in a laptop? Is the cell accessible at all?
>
> Most laptops and netbooks use Ni-HM batteries for the CMOS/RTC which the
> computer routinely recharges.


Formerly I thought CMOS batteries op PC were recharged, but then I learned,
for some reason, this is not the case. So what's the logic to do so only for
laptops?


> They rarely fail so I wouldn't worry too
> much about them. I would worry more about the florescent lamp, inverter,
> hard drive, and main battery myself. Although if you are still
> interested, it usually requires total disassembly to get to it.


I've already taken out the main battery to increase its lifespan.



--
regards,

|\ /|
| \/ |@rk
\../
\/os

In news:4ab6745e$0$83248$e4fe514c@news.xs4all.nl,
Linea Recta typed on Sun, 20 Sep 2009 20:27:39 +0200:
> "BillW50" <BillW50@aol.kom> schreef in bericht
> news:h95ed7$es$1@news.eternal-september.org...
>> In news:4ab6318a$0$83248$e4fe514c@news.xs4all.nl,
>> Linea Recta typed on Sun, 20 Sep 2009 15:43:35 +0200:
>>> In the past I have replaced the CMOS power cell of my PC, but I was
>>> wondering how is this done in a laptop? Is the cell accessible at
>>> all?
>>
>> Most laptops and netbooks use Ni-HM batteries for the CMOS/RTC which
>> the computer routinely recharges.
>
> Formerly I thought CMOS batteries op PC were recharged, but then I
> learned, for some reason, this is not the case. So what's the logic
> to do so only for laptops?

I am not sure. As desktops could be designed with a rechargeable and
laptops with a disposable. But it isn't generally the case. Maybe
because most people can take a desktop apart while most can't handle a
laptop disassembly I guess.

>> They rarely fail so I wouldn't worry too
>> much about them. I would worry more about the florescent lamp,
>> inverter, hard drive, and main battery myself. Although if you are
>> still interested, it usually requires total disassembly to get to it.
>
> I've already taken out the main battery to increase its lifespan.

That is a very good idea. Some claim you should use them every 2 months
or so to keep the capacity up. Although I haven't really seen any
evidence this is necessary. M.I.5¾ claims this by the way.

Do you also monitor the CPU and drive temps? The CPU temp monitoring
will let you know when it is time to do some dust bunny cleaning. <vbg>

--
Bill
Windows 2000 SP4 (5.00.2195)
Asus EEE PC 701G4 ~ 2GB RAM ~ 16GB-SDHC

"Power Cell"? You mean battery?

???

The CMOS batteries of laptops vary widely. Some are single use, some
are rechargeable. Some are "stock", some are custom. Some plug in,
some are soldered in. Some are accessible easily, some with moderate
difficulty, on some you have to remove the motherboard from the case
(e.g. battery on the bottom of the motherboard with no access cover
provided).

Take all of the possible combinations of all of the above variables and
you have a pretty good picture of the situation. Standard "coin cell"
batteries in sockets are extremely uncommon, however. It's usually much
more difficult than that.


Linea Recta wrote:
> In the past I have replaced the CMOS power cell of my PC, but I was
> wondering how is this done in a laptop? Is the cell accessible at all?
>
>
>

On Sun, 20 Sep 2009 20:27:39 +0200, "Linea Recta" <mccm.vos@abc.invalid> wrote:

>> Most laptops and netbooks use Ni-HM batteries for the CMOS/RTC which the
>> computer routinely recharges.

I can't believe that ais reloadable batteries would be a total shift in
politics.


>Formerly I thought CMOS batteries op PC were recharged, but then I learned,
>for some reason, this is not the case. So what's the logic to do so only for
>laptops?

Reloadable cells have a very short time to hold the energy. Also, putting them
onto a PCB would mean to include a loading circuit. It is a) more reliable and
b) MUCH cheaper to use a lithium cell.

In some cases, I fear, they already solder in the cells, so the cells can't be
replaced. The targeted market and the targeted lifespan differ totally from what
an ordinary buyer would guess.
--
"Jael lud Sisera ein, * Ließ sich auf das Lager sinken,
ihres Zeltes Gast zu sein. * Jael gab ihm Milch zu trinken.
Vor dem Feinde auf der Flucht, * Später ohne große Not
hatte dieser Schutz gesucht. * nagelt sie Sisera tot."
** ** ** ** ** ** ** ** ** ** ** http://www.reimbibel.de

"Linea Recta" <mccm.vos@abc.invalid> wrote in news:4ab6745e$0$83248
$e4fe514c@news.xs4all.nl:

> I've already taken out the main battery to increase its lifespan.
>
>

Totally unnecessary. Simply leave the laptop plugged in every chance
you get. Lithium-Ion and Lithium-Polymer batteries are float batteries,
unlike Ni-Cd and Ni-Mh cells. If you never discharge them below 80%,
and recharge them as soon as you can, they'll last for thousands of
charges. Deep discharging is so destructive, every battery has a
specially programmed IC in it to PREVENT you from discharging them below
50%. That's when the IC tells the computer to shut down to protect the
battery pack from ultimate destruction.

There is, and always has been, a problem with the IC and its
programming. What the IC THINKS is the current charge state of the pack
and what the REAL charge state of the pack is grow constantly wider
apart because the programming of the IC is an average for cells of this
type and the cells in your pack aren't average. So, every so often, I
like 2 months as a yardstick because my computer is discharged daily,
you need to "cycle" the battery pack to the point where the IC shuts
down the pack ("dead"), then IMMEDIATELY recharge the pack for a minimum
of 16 hours of continuous charging so the IC can find the point of full
charge, which it measures as a sudden rise of cell voltage under
charging current. A finishing charge, after the main high current
charge, is what takes so long and should not be disturbed. The IC will
shut down the charge, completely, to prevent overcharging which makes
these wonder batteries explode quite violently because cell warpage
results in internal shorting to hundreds of amps for a few
seconds..BOOM!

So, run it until it's dead every couple of months, then IMMEDIATELY
recharge for a minimum of 16 hours uninterrupted. All other times,
recharge it as quickly as you can find a power outlet to do so, and as
often as you can to reduce the destruction deep cycling causes. You get
many years of service out of them. This same method is also very useful
in your cellular and other Lithium-powered rechargeable devices.

If you store the battery pack for over 2 weeks without use, run the
laptop until the IC shuts down the laptop on discharge, then give it the
full 16 hour recharge cycle IMMEDIATELY, to reset the IC before you
start using the pack again. Lithium packs self-discharge something
awful as they leak like hell inside just sitting there, the nature of
the beast. The IC timer gets lost if it just sits and self-discharges.
Notice your initial instruction was to recharge the computer for 16-20
hours the day you got it...before using it to prevent you going really
deep in discharge from a confused charge IC allowing it to go way too
far. You ignored it, of course, everyone does and did initial damage to
a brand new battery pack the day you got it.....

Case in point....for any critics......

I have a Digital Mind Corporation (DMC) Xclef 500 120GB hard drive MP3
player/recorder/FM Radio:
http://pocketnow.com/review/digital-...-dmc-xclef-500

It's an antique by mp3 player standards. It even outlived the company!
I bought it the 2nd week it was offered for sale in the USA. Last
month, as I noticed its runtime of 22 hours was down to 10, I tore it
apart and replaced it 4/3 C cell Li-Ion 2000maH cell with a newfangled
4/3 C cell Li-Polymer 2800maH cell. Bought in early 2004, that's over 5
years of hard use as it's my main MP3 player in my work truck. I rest
my case about this method of making Lithium rechargeables have long
lives. 5 days/week x 52 weeks x 5 years = 1300 usage cycles, give or
take a few hundred as it was also used on weekends a lot.

This battery was so old, the charge controller was a separate PC board
held into the end of it by the shrinkwrap case. I had to move that
board to the new cell as I had to make my own battery pack. Works
great! Will now run about 30 hours continuously!

By the way, looking at the webpages, this monster player seems to be
still available with various drive sizes in it if you want a great
player without the glitz. The drives are standard 2.5" laptop drives
available anywhere and the OS supports up to one 137GB FAT16 partition.
Mine had a 40GB drive in it, initially, but a friend upgraded his big
laptop from 120GB to something much larger so gave me this 120GB Toshiba
drive. I reformatted it in a laptop and simply plugged it into the
Xclef HD-500 player. If you tell it to simply random play the entire
drive, I'm not sure how many thousands of hours that is, now..(c;] The
player has no copy protection games. You simply plug it into any
computer and it is recognized as an external USB hard drive by PC, Mac
or Linux boxes. As a USB drive, you can put any files on or off it with
any file manager, even a DOS window. No funny business. A great use
for it is as an extra, SELF-BATTERY-POWERED, hard drive for your
netbook! It uses no power from your netbook battery, unlike other USB
portable drives, so your runtime is the same. It runs much longer than
even my extended runtime, 9-cell Samsung NC10 is capable of running, so
just recharge it when you recharge the netbook and you have nearly
doubled your storage on a removable drive that's very easy to
load...with anything, not just music....(c;]

--
Larry

He's right, you are [generally] wrong.

Leaving a battery in a laptop will usually destroy it in 6 to 24 months.
There are multiple issues, a major issue is simple heat from other
heat generating components of the laptop. The charging circuit is also
an issue.


Larry wrote:
> "Linea Recta" <mccm.vos@abc.invalid> wrote in news:4ab6745e$0$83248
> $e4fe514c@news.xs4all.nl:
>
>> I've already taken out the main battery to increase its lifespan.
>>
>>
>
> Totally unnecessary. Simply leave the laptop plugged in every chance
> you get. Lithium-Ion and Lithium-Polymer batteries are float batteries,
> unlike Ni-Cd and Ni-Mh cells. If you never discharge them below 80%,
> and recharge them as soon as you can, they'll last for thousands of
> charges. Deep discharging is so destructive, every battery has a
> specially programmed IC in it to PREVENT you from discharging them below
> 50%. That's when the IC tells the computer to shut down to protect the
> battery pack from ultimate destruction.
>
> There is, and always has been, a problem with the IC and its
> programming. What the IC THINKS is the current charge state of the pack
> and what the REAL charge state of the pack is grow constantly wider
> apart because the programming of the IC is an average for cells of this
> type and the cells in your pack aren't average. So, every so often, I
> like 2 months as a yardstick because my computer is discharged daily,
> you need to "cycle" the battery pack to the point where the IC shuts
> down the pack ("dead"), then IMMEDIATELY recharge the pack for a minimum
> of 16 hours of continuous charging so the IC can find the point of full
> charge, which it measures as a sudden rise of cell voltage under
> charging current. A finishing charge, after the main high current
> charge, is what takes so long and should not be disturbed. The IC will
> shut down the charge, completely, to prevent overcharging which makes
> these wonder batteries explode quite violently because cell warpage
> results in internal shorting to hundreds of amps for a few
> seconds..BOOM!
>
> So, run it until it's dead every couple of months, then IMMEDIATELY
> recharge for a minimum of 16 hours uninterrupted. All other times,
> recharge it as quickly as you can find a power outlet to do so, and as
> often as you can to reduce the destruction deep cycling causes. You get
> many years of service out of them. This same method is also very useful
> in your cellular and other Lithium-powered rechargeable devices.
>
> If you store the battery pack for over 2 weeks without use, run the
> laptop until the IC shuts down the laptop on discharge, then give it the
> full 16 hour recharge cycle IMMEDIATELY, to reset the IC before you
> start using the pack again. Lithium packs self-discharge something
> awful as they leak like hell inside just sitting there, the nature of
> the beast. The IC timer gets lost if it just sits and self-discharges.
> Notice your initial instruction was to recharge the computer for 16-20
> hours the day you got it...before using it to prevent you going really
> deep in discharge from a confused charge IC allowing it to go way too
> far. You ignored it, of course, everyone does and did initial damage to
> a brand new battery pack the day you got it.....
>
> Case in point....for any critics......
>
> I have a Digital Mind Corporation (DMC) Xclef 500 120GB hard drive MP3
> player/recorder/FM Radio:
> http://pocketnow.com/review/digital-...-dmc-xclef-500
>
> It's an antique by mp3 player standards. It even outlived the company!
> I bought it the 2nd week it was offered for sale in the USA. Last
> month, as I noticed its runtime of 22 hours was down to 10, I tore it
> apart and replaced it 4/3 C cell Li-Ion 2000maH cell with a newfangled
> 4/3 C cell Li-Polymer 2800maH cell. Bought in early 2004, that's over 5
> years of hard use as it's my main MP3 player in my work truck. I rest
> my case about this method of making Lithium rechargeables have long
> lives. 5 days/week x 52 weeks x 5 years = 1300 usage cycles, give or
> take a few hundred as it was also used on weekends a lot.
>
> This battery was so old, the charge controller was a separate PC board
> held into the end of it by the shrinkwrap case. I had to move that
> board to the new cell as I had to make my own battery pack. Works
> great! Will now run about 30 hours continuously!
>
> By the way, looking at the webpages, this monster player seems to be
> still available with various drive sizes in it if you want a great
> player without the glitz. The drives are standard 2.5" laptop drives
> available anywhere and the OS supports up to one 137GB FAT16 partition.
> Mine had a 40GB drive in it, initially, but a friend upgraded his big
> laptop from 120GB to something much larger so gave me this 120GB Toshiba
> drive. I reformatted it in a laptop and simply plugged it into the
> Xclef HD-500 player. If you tell it to simply random play the entire
> drive, I'm not sure how many thousands of hours that is, now..(c;] The
> player has no copy protection games. You simply plug it into any
> computer and it is recognized as an external USB hard drive by PC, Mac
> or Linux boxes. As a USB drive, you can put any files on or off it with
> any file manager, even a DOS window. No funny business. A great use
> for it is as an extra, SELF-BATTERY-POWERED, hard drive for your
> netbook! It uses no power from your netbook battery, unlike other USB
> portable drives, so your runtime is the same. It runs much longer than
> even my extended runtime, 9-cell Samsung NC10 is capable of running, so
> just recharge it when you recharge the netbook and you have nearly
> doubled your storage on a removable drive that's very easy to
> load...with anything, not just music....(c;]
>

"BillW50" <BillW50@aol.kom> wrote in message
news:h95ed7$es$1@news.eternal-september.org...
> In news:4ab6318a$0$83248$e4fe514c@news.xs4all.nl,
> Linea Recta typed on Sun, 20 Sep 2009 15:43:35 +0200:
>> In the past I have replaced the CMOS power cell of my PC, but I was
>> wondering how is this done in a laptop? Is the cell accessible at all?
>
> Most laptops and netbooks use Ni-HM batteries for the CMOS/RTC which the
> computer routinely recharges. They rarely fail so I wouldn't worry too
> much about them. I would worry more about the florescent lamp, inverter,
> hard drive, and main battery myself. Although if you are still
> interested, it usually requires total disassembly to get to it.
>

While some use Ni-MH, they are nowhere near universal. Around 50% or so
still use a lithium coin battery. Ni-MH batteries do routinely fail as the
succumb to Nickel whisker growth.

As for replacing it. I varies considerable with some designs making them
easy to get at, while other require a minor or even major disassembly.

"BillW50" <BillW50@aol.kom> wrote in message
news:h95to0$sc0$1@news.eternal-september.org...
> In news:4ab6745e$0$83248$e4fe514c@news.xs4all.nl,
> Linea Recta typed on Sun, 20 Sep 2009 20:27:39 +0200:
>> "BillW50" <BillW50@aol.kom> schreef in bericht
>> news:h95ed7$es$1@news.eternal-september.org...
>>> In news:4ab6318a$0$83248$e4fe514c@news.xs4all.nl,
>>> Linea Recta typed on Sun, 20 Sep 2009 15:43:35 +0200:
>>>> In the past I have replaced the CMOS power cell of my PC, but I was
>>>> wondering how is this done in a laptop? Is the cell accessible at
>>>> all?
>>>
>>> Most laptops and netbooks use Ni-HM batteries for the CMOS/RTC which
>>> the computer routinely recharges.
>>
>> Formerly I thought CMOS batteries op PC were recharged, but then I
>> learned, for some reason, this is not the case. So what's the logic
>> to do so only for laptops?
>
> I am not sure. As desktops could be designed with a rechargeable and
> laptops with a disposable. But it isn't generally the case. Maybe
> because most people can take a desktop apart while most can't handle a
> laptop disassembly I guess.
>
>>> They rarely fail so I wouldn't worry too
>>> much about them. I would worry more about the florescent lamp,
>>> inverter, hard drive, and main battery myself. Although if you are
>>> still interested, it usually requires total disassembly to get to it.
>>
>> I've already taken out the main battery to increase its lifespan.
>
> That is a very good idea. Some claim you should use them every 2 months
> or so to keep the capacity up. Although I haven't really seen any
> evidence this is necessary. M.I.5¾ claims this by the way.
>

It's not actually my claim. I work in the Aerospace industry and this is
the prevailing wisdom. It seems to have merit because Li-ion batteries
certainly seem to deteriorate if they are left idle.

"Barry Watzman" <WatzmanNOSPAM@neo.rr.com> wrote in message
news:h96g0o$hq8$1@news.eternal-september.org...
> He's right, you are [generally] wrong.
>
> Leaving a battery in a laptop will usually destroy it in 6 to 24 months.
> There are multiple issues, a major issue is simple heat from other heat
> generating components of the laptop. The charging circuit is also an
> issue.
>

This has been discussed before, but the charging circuit shouldn't be an
issue (if it's designed properly). Li-ion batteries are able to operate in
float charge mode because in this mode the charger merely makes up the
charge loss due to self discharge. It should not be attempting to pass any
net charging current as such. Li-ion battery chargers that overcharge are
easy to spot as the resulting fireball is hard to miss.

"Larry" <noone@home.com> wrote in message
news:Xns9C8C9D3378E2Anoonehomecom@74.209.131.13...
> "Linea Recta" <mccm.vos@abc.invalid> wrote in news:4ab6745e$0$83248
> $e4fe514c@news.xs4all.nl:
>
>> I've already taken out the main battery to increase its lifespan.
>>
>>
>
> Totally unnecessary. Simply leave the laptop plugged in every chance
> you get. Lithium-Ion and Lithium-Polymer batteries are float batteries,
> unlike Ni-Cd and Ni-Mh cells. If you never discharge them below 80%,
> and recharge them as soon as you can, they'll last for thousands of
> charges. Deep discharging is so destructive, every battery has a
> specially programmed IC in it to PREVENT you from discharging them below
> 50%. That's when the IC tells the computer to shut down to protect the
> battery pack from ultimate destruction.
>

Complete rubbish! It is the laptop internally generated heat that destroys
the batteries when you leave them in.

Where did you get all this garbage about no discharging li-ion batteries
below 80%? Li-ion batteries are designed to be discharged and charged.
There is a lower limit but its 0% charge (which is regarded as being 2.8
volts per cell (2.5 volts for some Sony designs)). Most equipment uses 3.0
volts as 0% to avoid the problems with over discharge. Battery controllers
do not prevent cells being discharged below 50% and I regularly discharge
li-ion batteries to near 0% (or even 0%). Most laptops are set up to shut
the machine down at or around 5%, but this is something Windows does rather
than the controller.

> There is, and always has been, a problem with the IC and its
> programming. What the IC THINKS is the current charge state of the pack
> and what the REAL charge state of the pack is grow constantly wider
> apart because the programming of the IC is an average for cells of this
> type and the cells in your pack aren't average. So, every so often, I
> like 2 months as a yardstick because my computer is discharged daily,
> you need to "cycle" the battery pack to the point where the IC shuts
> down the pack ("dead"), then IMMEDIATELY recharge the pack for a minimum
> of 16 hours of continuous charging so the IC can find the point of full
> charge, which it measures as a sudden rise of cell voltage under
> charging current. A finishing charge, after the main high current
> charge, is what takes so long and should not be disturbed. The IC will
> shut down the charge, completely, to prevent overcharging which makes
> these wonder batteries explode quite violently because cell warpage
> results in internal shorting to hundreds of amps for a few
> seconds..BOOM!
>

You can charge your batteries for 16 hours if you wish, but the cells won't
actually charge for anything like that long. Once the main charge period
ends (usually when the charge indicator goes out orwhatever it does), the
battery is floated across a constant voltage source of 4.2 volts per cell.
Once the cell voltage rises to match the 4.2 volts the charge current stops
(apart from an extremely small trickle that offsets self discharge). This
occurs within about an hour of the end of main charge.

> So, run it until it's dead every couple of months, then IMMEDIATELY
> recharge for a minimum of 16 hours uninterrupted. All other times,
> recharge it as quickly as you can find a power outlet to do so, and as
> often as you can to reduce the destruction deep cycling causes. You get
> many years of service out of them. This same method is also very useful
> in your cellular and other Lithium-powered rechargeable devices.
>

Running the battery down to the point the laptop auto shuts down is a good
idea because it is this that allows the battery monitor to calibrate itself.
It is only necessary to recharge for one hour after the charge indicator
goes out. There is no advantage to charging for longer. Deep discharging
to 0% (i.e. 2.8 volts per cell does no harm or damage whatsoever).

> If you store the battery pack for over 2 weeks without use, run the
> laptop until the IC shuts down the laptop on discharge, then give it the
> full 16 hour recharge cycle IMMEDIATELY, to reset the IC before you
> start using the pack again. Lithium packs self-discharge something
> awful as they leak like hell inside just sitting there, the nature of
> the beast. The IC timer gets lost if it just sits and self-discharges.
> Notice your initial instruction was to recharge the computer for 16-20
> hours the day you got it...before using it to prevent you going really
> deep in discharge from a confused charge IC allowing it to go way too
> far. You ignored it, of course, everyone does and did initial damage to
> a brand new battery pack the day you got it.....
>

There is nothing in that paragraph that equates to reality. Li-ion
batteries have to lowest self discharge rate of any rechargeable battery
(apart from one relatively new Sony design). Li-ion batteries will have
almost their full capacity after doing nothing for 3 months (or even more)
after they are charged. However, the battery monitor circuit does take some
current in some battery designs. Battery monitors do not contain any timer,
they merely monitor voltage and current.

> Case in point....for any critics......
>
> I have a Digital Mind Corporation (DMC) Xclef 500 120GB hard drive MP3
> player/recorder/FM Radio:
> http://pocketnow.com/review/digital-...-dmc-xclef-500
>
> It's an antique by mp3 player standards. It even outlived the company!
> I bought it the 2nd week it was offered for sale in the USA. Last
> month, as I noticed its runtime of 22 hours was down to 10, I tore it
> apart and replaced it 4/3 C cell Li-Ion 2000maH cell with a newfangled
> 4/3 C cell Li-Polymer 2800maH cell. Bought in early 2004, that's over 5
> years of hard use as it's my main MP3 player in my work truck. I rest
> my case about this method of making Lithium rechargeables have long
> lives. 5 days/week x 52 weeks x 5 years = 1300 usage cycles, give or
> take a few hundred as it was also used on weekends a lot.
>

I have batteries that are 15 years old that have been treated by ignoring
your rubbish advice. Indeed I've never seen any of the rubbish you've
spouted before and I work in the Aerospace industry where we use a lot of
batteries of many chemistries. There is currently no li-ion technology that
will last for 1300 full charge and discharge cycles. The one unfortunate
aspect of the technology is that it does have the lowest charge/discharge
capability of any recognised rechargeable chemistry (typically 300-500 full
cycles)

"M.I.5¾" <no.one@no.where.NO_SPAM.co.uk> wrote in
news:4ab754c4$1_1@glkas0286.greenlnk.net:

> Complete rubbish! It is the laptop internally generated heat that
> destroys the batteries when you leave them in.
>

You must be using a MAC. REAL laptops have EXTERNAL and CHANGEABLE
batteries that are on the OUTSIDE of them....for a reason....



--
Larry

"M.I.5¾" <no.one@no.where.NO_SPAM.co.uk> wrote in
news:4ab754c4$1_1@glkas0286.greenlnk.net:

> Where did you get all this garbage about no discharging li-ion
> batteries below 80%? Li-ion batteries are designed to be discharged
> and charged. There is a lower limit but its 0% charge (which is
> regarded as being 2.8 volts per cell (2.5 volts for some Sony
> designs)). Most equipment uses 3.0 volts as 0% to avoid the problems
> with over discharge. Battery controllers do not prevent cells being
> discharged below 50% and I regularly discharge li-ion batteries to
> near 0% (or even 0%). Most laptops are set up to shut the machine
> down at or around 5%, but this is something Windows does rather than
> the controller.
>
>

http://batteryuniversity.com/

http://www.batteryuniversity.com/partone-5.htm

http://uber.la/archives/4565
for the Macbooks amoungst us sacked with glitz instead of logic.



--
Larry