"John Doue" <notwobe******.com> wrote in message
news:JvdVk.144$jw1.66@read4.inet.fi...
> M.I.5¾ wrote:
>> "AJL" <nomail@fakeaddress.com> wrote in message
>> news:scu6i4d4o7pkc10l84ujm8ajts6ejk7am3@4ax.com...
>>> Barry Watzman <WatzmanNOSPAM@neo.rr.com> wrote:
>>>
>>>> What can kill a battery is a
>>>> combination of overcharging and heat (either from within the battery or
>>> >from external sources). Some laptops are well designed in these
>>>> regards, others, however are not.
>>>> (I'd say that most are not, based on experience).
>>> Rather a poor supposition don't you think? The number of laptops that
>>> are poorly designed in your "experience" must be minuscule compared to
>>> the thousands of other models in service.
>>>
>> Actually, I rather agree with the poster you replied to. Poorly designed
>> in this case means placing heat generating components such as the hard
>> disc drive or processor near to the battery such that it warms up in use.
>> From what I can tell, little consideration is given to the temperature
>> problems of the battery and if a laptop design is encountered that
>> doesn't significantly heat the battery, then it is more by luck than any
>> design requirement. The laptop makers have no real vested interest in
>> protecting the battery from the effects of heat - not at a $100-200 a go.
> You are most probably right for most laptops. However, I believe that
> business series pay more attention to such matters since they need to
> convince big accounts managers of the quality / reliability of their
> products.
>

If the laptops used in this business environment are anything to go by, this
would not seem to be the case. But having said that, the life of batteries
used in a business environment are far more likely to be determined by the
number of charge/dicharge cycles. Using the battery every day on the train
to/from the office complete with a recharge will wear the battery out in
well under a year (300 or so full cycles).

> Whichever way we look at the battery issue, I find it unconscionable that
> battery replacement would be so expensive compared to the price of laptop.
> Is it the same issue as printer cartridges or is there a really valid
> reason for those sky high prices?
>

The price of the battery is certainly vastly greater than the price of the
cells that go to make it up and, as you note, is a significant percentage of
the laptop price. It seems to me that the price of any consumable (and that
is what the battery is) for modern IT equipment is priced according to the
Tom Watson Snr (of IBM fame) model. Once you have locked the customer in to
buying your consumables, squeeze him for every penny. The profit in these
consumables is certainly outrageous compared with their obvious
manufacturing costs.

"Val" <vmanes@NOSPAMrap.midco.net> wrote in message
news:FLqdncEfddhlobvUnZ2dnUVZ_tHinZ2d@midco.net...
> Doesn't wear mean a lessened ability to take/hold a charge? If the
> battery,
> at present full charge, runs less time than it did when new, isn't that
> runtime difference the amount of wear?
>
> As to "citation needed", I interpret that to indicate a lack of validation
> of what's posted on the wiki. Doesn't mean it's not true, just not yet
> supported by evidence. Thus, not be trusted (or rather, to trusted less
> than
> one might trust other wiki entries.)
>

This varies somewhat depending on who put the {{fact}} tag there.
Generally, wiki requires that information presented has verifiable citations
and much of it does. However, there is much that does not have citations
for various reasons. In these cases, some users just add the {{fact}} tag
purely because there is no citation. Personally I believe this is often
counter productive as some subject matter will inevitably rely on someone's
knowledge and experience. Others will add the {{fact}} tag to uncited
information that either looks unbelievable or because they do not think it
is correct, and I think that this is a better use provided a suitable entry
is made on the discussion page stating the objection. But in any case the
[citation needed] flag should alert the reader that things may not be as
they appear.

"Val" <vmanes@NOSPAMrap.midco.net> wrote in message
news:FLqdncEfddhlobvUnZ2dnUVZ_tHinZ2d@midco.net...
> Doesn't wear mean a lessened ability to take/hold a charge? If the
> battery,
> at present full charge, runs less time than it did when new, isn't that
> runtime difference the amount of wear?
>
> As to "citation needed", I interpret that to indicate a lack of validation
> of what's posted on the wiki. Doesn't mean it's not true, just not yet
> supported by evidence. Thus, not be trusted (or rather, to trusted less
> than
> one might trust other wiki entries.)
>

This varies somewhat depending on who put the {{fact}} tag there.
Generally, wiki requires that information presented has verifiable citations
and much of it does. However, there is much that does not have citations
for various reasons. In these cases, some users just add the {{fact}} tag
purely because there is no citation. Personally I believe this is often
counter productive as some subject matter will inevitably rely on someone's
knowledge and experience. Others will add the {{fact}} tag to uncited
information that either looks unbelievable or because they do not think it
is correct, and I think that this is a better use provided a suitable entry
is made on the discussion page stating the objection. But in any case the
[citation needed] flag should alert the reader that things may not be as
they appear.

The do need some occasional use ... in fact they can die without ANY
use. But we are talking about using them a tiny bit once every 3 to 9
months.

BillW50 wrote:

>> The best advice for a laptop to be used in a predominantly non-mobile,
>> almost always on AC application is to remove the battery (if you need
>> a UPS, get a UPS. A $30 ups is cheaper than a $200 lithium battery).
>
> I too feel the same way. Although I seem to recall M.I.5¾ believing that
> Li-Ion lasts longer if they get some occasional use (I personally can't
> say either way on that one). But I feel this is true of lead acid
> batteries, but M.I.5¾ disagrees with me there.
>
** Posted from http://www.teranews.com **

Barry Watzman wrote:
> The do need some occasional use ... in fact they can die without ANY
> use. But we are talking about using them a tiny bit once every 3 to 9
> months.
>
> BillW50 wrote:
>
>>> The best advice for a laptop to be used in a predominantly
>>> non-mobile, almost always on AC application is to remove the battery
>>> (if you need a UPS, get a UPS. A $30 ups is cheaper than a $200
>>> lithium battery).
>>
>> I too feel the same way. Although I seem to recall M.I.5¾ believing
>> that Li-Ion lasts longer if they get some occasional use (I personally
>> can't say either way on that one). But I feel this is true of lead
>> acid batteries, but M.I.5¾ disagrees with me there.

You mean both discharging and charging, or just one or the other?

--
Bill
Asus EEE PC 8GB 1GB SoDIMM Adata 16GB
Windows XP SP2 and Xandros Linux

The do need some occasional use ... in fact they can die without ANY
use. But we are talking about using them a tiny bit once every 3 to 9
months.

BillW50 wrote:

>> The best advice for a laptop to be used in a predominantly non-mobile,
>> almost always on AC application is to remove the battery (if you need
>> a UPS, get a UPS. A $30 ups is cheaper than a $200 lithium battery).
>
> I too feel the same way. Although I seem to recall M.I.5¾ believing that
> Li-Ion lasts longer if they get some occasional use (I personally can't
> say either way on that one). But I feel this is true of lead acid
> batteries, but M.I.5¾ disagrees with me there.
>
** Posted from http://www.teranews.com **

Val wrote:
> Doesn't wear mean a lessened ability to take/hold a charge?

Well not really. It means that the capacity (run time - kind of like
your gas tank gets smaller and smaller) is dropping. A Li-Ion battery
will continue to take and hold a charge till about 95% of the capacity
is gone. Then it starts having a problem taking and holding a charge.

--
Bill
Asus EEE PC 8GB 1GB SoDIMM Adata 16GB
Windows XP SP2 and Xandros Linux

Val wrote:
> Doesn't wear mean a lessened ability to take/hold a charge?

Well not really. It means that the capacity (run time - kind of like
your gas tank gets smaller and smaller) is dropping. A Li-Ion battery
will continue to take and hold a charge till about 95% of the capacity
is gone. Then it starts having a problem taking and holding a charge.

--
Bill
Asus EEE PC 8GB 1GB SoDIMM Adata 16GB
Windows XP SP2 and Xandros Linux

Barry Watzman wrote:
> The do need some occasional use ... in fact they can die without ANY
> use. But we are talking about using them a tiny bit once every 3 to 9
> months.
>
> BillW50 wrote:
>
>>> The best advice for a laptop to be used in a predominantly
>>> non-mobile, almost always on AC application is to remove the battery
>>> (if you need a UPS, get a UPS. A $30 ups is cheaper than a $200
>>> lithium battery).
>>
>> I too feel the same way. Although I seem to recall M.I.5¾ believing
>> that Li-Ion lasts longer if they get some occasional use (I personally
>> can't say either way on that one). But I feel this is true of lead
>> acid batteries, but M.I.5¾ disagrees with me there.

You mean both discharging and charging, or just one or the other?

--
Bill
Asus EEE PC 8GB 1GB SoDIMM Adata 16GB
Windows XP SP2 and Xandros Linux

BillW50 wrote:
> Val wrote:
>> Doesn't wear mean a lessened ability to take/hold a charge?
>
> Well not really. It means that the capacity (run time - kind of like
> your gas tank gets smaller and smaller) is dropping. A Li-Ion battery
> will continue to take and hold a charge till about 95% of the capacity
> is gone. Then it starts having a problem taking and holding a charge.
>
My experience is all with laptops prior to 2005, but I've never had
a battery fail because it wouldn't hold a charge. Mine fail because
the internal resistance goes up to the point that the laptop
shuts down WELL before consuming all the available electrons.
I've done extensive capacity tests at various currents.
The electrons are in there, the laptop just won't take 'em.

While on the subject...
I have two laptop batteries where ALL 8 of the cells are open-circuit
with no signs of overheating. I can understand how one cell of a series
string can pop it's internal breaker, but all 8???
Came with a used laptop, so no idea the history.

"Val" <vmanes@NOSPAMrap.midco.net> wrote in message
news:yO-dnYowtqhe1L_UnZ2dnUVZ_qzinZ2d@midco.net...
> Tell that to my three year old battery, kept in the laptop, used almost
> daily, put back on AC so it stays topped off, stored at room temperature.
> Battery wear, as indicated by mobilemeter program, and verified by actual
> run time, is only 15%.
>
> I see an awful lot of "citation needed" in that wiki.
>

Wear and charge are different things.

The "citation needed" is there for a good reason.

BillW50 wrote:
> Val wrote:
>> Doesn't wear mean a lessened ability to take/hold a charge?
>
> Well not really. It means that the capacity (run time - kind of like
> your gas tank gets smaller and smaller) is dropping. A Li-Ion battery
> will continue to take and hold a charge till about 95% of the capacity
> is gone. Then it starts having a problem taking and holding a charge.
>
My experience is all with laptops prior to 2005, but I've never had
a battery fail because it wouldn't hold a charge. Mine fail because
the internal resistance goes up to the point that the laptop
shuts down WELL before consuming all the available electrons.
I've done extensive capacity tests at various currents.
The electrons are in there, the laptop just won't take 'em.

While on the subject...
I have two laptop batteries where ALL 8 of the cells are open-circuit
with no signs of overheating. I can understand how one cell of a series
string can pop it's internal breaker, but all 8???
Came with a used laptop, so no idea the history.

"BillW50" <BillW50@aol.kom> wrote in message
news:gfvsl7$snt$1@nntp.motzarella.org...
> Barry Watzman wrote:
>> I also don't agree with Bill. But, that said, there is a lot of unit to
>> unit (really model to model) variation. What can kill a battery is a
>> combination of overcharging and heat (either from within the battery or
>> from external sources). Some laptops are well designed in these regards,
>> others, however are not (I'd say that most are not, based on experience).
>
> What Li-Ion battery chargers over charge the battery? As over charging
> Li-Ion batteries could cause the battery to explode. This is a big no-no!
> So I seriously doubt any laptop is over charging batteries.
>

The problem here is that a lot of advice about removal of the battery blames
overcharging, and to the less technically minded users, this seems a
perfectly reasonable explanation. Thus it gets propagated (and has even
turned up here).

> And that 20% per year was quoted at room temperature and keeping the
> battery voltage charged to 4.2v per cell. And that is what I have found
> too. Change either or, and my results would be different too.
>

The actual depletion rate depends very much on the battery construction, but
generally 20% loss of charge per year at 20 C is a good figure for most
constructions. There is a relatively new construction from Sony that has a
lower average voltage (of 3.4 volts per cell) and a charge loss rate of
nearly 20% *per month*.

>> The best advice for a laptop to be used in a predominantly non-mobile,
>> almost always on AC application is to remove the battery (if you need a
>> UPS, get a UPS. A $30 ups is cheaper than a $200 lithium battery).
>
> I too feel the same way. Although I seem to recall M.I.5¾ believing that
> Li-Ion lasts longer if they get some occasional use (I personally can't
> say either way on that one).

This is advice from the battery manufacturers. My own experience suggests
that it may be the case.

> But I feel this is true of lead acid batteries, but M.I.5¾ disagrees with
> me there.
>

This disagreement comes from the fact that the act of discharging a lead
acid battery actually does a small amount of physical damage. This is
because both the positive and negative plates get larger as they absorb the
sulphate from the acid electrolyte. This size change causes the plate to
shed a small amount of the brittle active material. Simply keeping the
battery charged keeps the plates a constant size. If the battery is allowed
to stand, the self discharge causes the plates once more to absorb sulphate
from the electrolyte. If the lead sulphate is not converted back to lead
(-ve) and lead dioxide (+ve) via a regular charge it looses its spongy form
and becomes a hard deposit. Once it becomes hard, it ceases to absorb the
electrolyte and becomes impossible to break down by charging. The shed
material and the sulphation (as it is called) are the 2 failure modes for
lead acid batteries.

The ideal storage mode for lead acid batteries is to constantly pass a small
charging current through them that just balances the charge loss due to self
discharge. In practice, it is more usual to give them a periodic charge to
offset the self discharge every 2 to 4 weeks.

"AJL" <nomail@fakeaddress.com> wrote in message
news:scu6i4d4o7pkc10l84ujm8ajts6ejk7am3@4ax.com...
> Barry Watzman <WatzmanNOSPAM@neo.rr.com> wrote:
>
>>What can kill a battery is a
>>combination of overcharging and heat (either from within the battery or
>>from external sources). Some laptops are well designed in these
>>regards, others, however are not.
>
>>(I'd say that most are not, based on experience).
>
> Rather a poor supposition don't you think? The number of laptops that
> are poorly designed in your "experience" must be minuscule compared to
> the thousands of other models in service.
>
Actually, I rather agree with the poster you replied to. Poorly designed in
this case means placing heat generating components such as the hard disc
drive or processor near to the battery such that it warms up in use. From
what I can tell, little consideration is given to the temperature problems
of the battery and if a laptop design is encountered that doesn't
significantly heat the battery, then it is more by luck than any design
requirement. The laptop makers have no real vested interest in protecting
the battery from the effects of heat - not at a $100-200 a go.

"Val" <vmanes@NOSPAMrap.midco.net> wrote in message
news:yO-dnYowtqhe1L_UnZ2dnUVZ_qzinZ2d@midco.net...
> Tell that to my three year old battery, kept in the laptop, used almost
> daily, put back on AC so it stays topped off, stored at room temperature.
> Battery wear, as indicated by mobilemeter program, and verified by actual
> run time, is only 15%.
>
> I see an awful lot of "citation needed" in that wiki.
>

Wear and charge are different things.

The "citation needed" is there for a good reason.