Laptop battery advice

[Bobby]

Archived from groups: alt.comp.hardware,comp.sys.laptops,microsoft.public.windowsxp.general,microsoft.public.windowsxp.hardware,uk.comp.sys.laptops (More info?)

What is the best way to use a new laptop?

The manufacturer points out that the battery has a limited number of
recharge cycles and recommends that I fully charge and discharge the battery
every time I use it - but that's not practical.

Most likely I will use the battery for an hour or two and then connect it to
the mains supply. Is that bad for the battery?

Also, what sort of activity drains the battery most? Is there a website
which lists this?

Cheers.

Bobby

 

[Guest]

Archived from groups: alt.comp.hardware,comp.sys.laptops,microsoft.public.windowsxp.general,microsoft.public.windowsxp.hardware,uk.comp.sys.laptops (More info?)

Bobby wrote:

> What is the best way to use a new laptop?
>
> The manufacturer points out that the battery has a limited number of
> recharge cycles and recommends that I fully charge and discharge the
> battery every time I use it - but that's not practical.
>
> Most likely I will use the battery for an hour or two and then connect it
> to the mains supply. Is that bad for the battery?
>
> Also, what sort of activity drains the battery most? Is there a website
> which lists this?
>
> Cheers.
>
> Bobby

http/www.surfbaud.co.uk/knowledgebase/
disclaimer, my site so I'm biased.

--
Lithium ion internal and external batteries.
Internal from £30 External from £75 (trade)
All batteries factory new and guaranteed.
http/www.surfbaud.co.uk/
e-mail qnirahyy@oyhrlbaqre.pb.hx (www.rot13.com)

 

[Bobby]

Archived from groups: alt.comp.hardware,comp.sys.laptops,microsoft.public.windowsxp.general,microsoft.public.windowsxp.hardware,uk.comp.sys.laptops (More info?)

Thanks for the link. I've bookmarked your site. Some excellent advice - and
good prices!

But it seems to me (from reading your site) that Li-ion batteries have a
limited life (36 months) so it the charge-discharge cycle isn't very
important since the battery will wither before any bad charging practices
have an affect. Is that the case? If not, why not?

Cheers.

Bobby

"Guy Fawkes" <look@my.sig> wrote in message
news:K9nde.1485$St6.348@fe26.usenetserver.com...
> Bobby wrote:
>
>> What is the best way to use a new laptop?
>>
>> The manufacturer points out that the battery has a limited number of
>> recharge cycles and recommends that I fully charge and discharge the
>> battery every time I use it - but that's not practical.
>>
>> Most likely I will use the battery for an hour or two and then connect it
>> to the mains supply. Is that bad for the battery?
>>
>> Also, what sort of activity drains the battery most? Is there a website
>> which lists this?
>>
>> Cheers.
>>
>> Bobby
>
> http/www.surfbaud.co.uk/knowledgebase/
> disclaimer, my site so I'm biased.
>
> --
> Lithium ion internal and external batteries.
> Internal from £30 External from £75 (trade)
> All batteries factory new and guaranteed.
> http/www.surfbaud.co.uk/
> e-mail qnirahyy@oyhrlbaqre.pb.hx (www.rot13.com)
>

 

[Guest]

Archived from groups: alt.comp.hardware,comp.sys.laptops,microsoft.public.windowsxp.general,microsoft.public.windowsxp.hardware,uk.comp.sys.laptops (More info?)

Bobby wrote:

> Thanks for the link. I've bookmarked your site. Some excellent advice -
> and good prices!
>
> But it seems to me (from reading your site) that Li-ion batteries have a
> limited life (36 months) so it the charge-discharge cycle isn't very
> important since the battery will wither before any bad charging practices
> have an affect. Is that the case? If not, why not?

the chemical compounds that make up a cell start decaying slowly from the
moment they are made, the 36 months is a figure I have come up with based
on experience.

charge / discharge cycles are also a decaying process, not a binary event,
eg at x cycles suddenly no more power, it more like something wearing out
when used hard, maybe emergency stops from 70 mph on a set of tyres

if you get 500 full charge/discharge cycles per battery most users are only
going to do a full cycle twice a week, so five years of charge discharge,
so that level of use isn't likely to kill the battery early.

discharge / charge full twice a day (it's possible, we have several
customers who fully discharge / charged > once a day 6 days a week who now
run off our universal external batteries) and the cycles kill the battery
in about nine monthd, long before the ageing process.

there are some analogies to car tyres, fit 4 new one and

1/ they will age, crack and rot in the garage even if you do zero miles,
eventually
2/ they will die very very quickly if you wheelspin away from one set of
lights and screech to a halt at the next
3/ they will last longest if used regularly, carefully, sensitively.

HTH etc


--
Lithium ion internal and external batteries.
Internal from £30 External from £75 (trade)
All batteries factory new and guaranteed.
http/www.surfbaud.co.uk/
e-mail qnirahyy@oyhrlbaqre.pb.hx (www.rot13.com)

 

[Guest]

Archived from groups: alt.comp.hardware,comp.sys.laptops,microsoft.public.windowsxp.general,microsoft.public.windowsxp.hardware,uk.comp.sys.laptops (More info?)

These batteries will last about 3 years average. The older type NiCads had
memory problems. It is good to run down the battery every number of months,
but it is not critical as with the early generation of batteries. I would
not be overly worried about this.

--

JANA
_____


"Bobby" <bobby@aventuremail.com> wrote in message
news:3dm8mhF6qv4hhU1@individual.net...
What is the best way to use a new laptop?

The manufacturer points out that the battery has a limited number of
recharge cycles and recommends that I fully charge and discharge the battery
every time I use it - but that's not practical.

Most likely I will use the battery for an hour or two and then connect it to
the mains supply. Is that bad for the battery?

Also, what sort of activity drains the battery most? Is there a website
which lists this?

Cheers.

Bobby

 

[Guest]

Archived from groups: comp.sys.laptops (More info?)

There have been 3 different battery systems used in laptops, NiCad, NiMH
and Lithium. Some of the advice still being given out (on systems with
Lithium batteries) is old, outdated advice that was only applicable to
NiCad (the oldest and by far the worst of the 3 technologies).

All of the batteries do have a limited number of discharge cycles. The
number is typically in the range of 300 to 500 for lithium batteries.
It's not totally clear to me how this applies to partial cycles.

The "full charge and discharge" advice only applies to NiCad batteries.
There is no need to do this for Lithium batteries and it may even be
harmful. Lithium batteries last longest if they are discharged below
about 20% to 25%. [Some people say they should also not be charged
above about 95%]. Manufacturers recommend long term storage of lithium
batteries at about half-charge, but personally I've stored them fully
charged and not seen significant adverse effects (and I have quite a few
10-year old lithium batteries that will still run a laptop for 2 hours).


Bobby wrote:

> What is the best way to use a new laptop?
>
> The manufacturer points out that the battery has a limited number of
> recharge cycles and recommends that I fully charge and discharge the battery
> every time I use it - but that's not practical.
>
> Most likely I will use the battery for an hour or two and then connect it to
> the mains supply. Is that bad for the battery?
>
> Also, what sort of activity drains the battery most? Is there a website
> which lists this?
>
> Cheers.
>
> Bobby
>
>

 

[Guest]

Archived from groups: comp.sys.laptops (More info?)

Ooops. "Lithium batteries last longest if they are discharged below
about 20% to 25%" should read "if they are NOT discharged below about
20% to 25%"

Just a minor omission there ......


Barry Watzman wrote:

> There have been 3 different battery systems used in laptops, NiCad, NiMH
> and Lithium. Some of the advice still being given out (on systems with
> Lithium batteries) is old, outdated advice that was only applicable to
> NiCad (the oldest and by far the worst of the 3 technologies).
>
> All of the batteries do have a limited number of discharge cycles. The
> number is typically in the range of 300 to 500 for lithium batteries.
> It's not totally clear to me how this applies to partial cycles.
>
> The "full charge and discharge" advice only applies to NiCad batteries.
> There is no need to do this for Lithium batteries and it may even be
> harmful. Lithium batteries last longest if they are discharged below
> about 20% to 25%. [Some people say they should also not be charged
> above about 95%]. Manufacturers recommend long term storage of lithium
> batteries at about half-charge, but personally I've stored them fully
> charged and not seen significant adverse effects (and I have quite a few
> 10-year old lithium batteries that will still run a laptop for 2 hours).
>
>
> Bobby wrote:
>
>> What is the best way to use a new laptop?
>>
>> The manufacturer points out that the battery has a limited number of
>> recharge cycles and recommends that I fully charge and discharge the
>> battery every time I use it - but that's not practical.
>>
>> Most likely I will use the battery for an hour or two and then connect
>> it to the mains supply. Is that bad for the battery?
>>
>> Also, what sort of activity drains the battery most? Is there a
>> website which lists this?
>>
>> Cheers.
>>
>> Bobby
>>

 

[Bobby]

Archived from groups: comp.sys.laptops (More info?)

Thanks for this Barry.

Your advice appears to be consistent with something else I read - the Li Ion
batteries do not suffer from the memory effect.

So it sounds to me that the "normal" full charge/partial discharge cycle
(which is the natural way to use a laptop i.e. connected to the main most of
the time but occasionally used on the battery for an hour or two) is best
for these batteries?

I was advised the fully charge and fully discharge the battery when its new.
Is that advice sound?

Bobby

"Barry Watzman" <WatzmanNOSPAM@neo.rr.com> wrote in message
news:42763BF0.4040507@neo.rr.com...
> Ooops. "Lithium batteries last longest if they are discharged below about
> 20% to 25%" should read "if they are NOT discharged below about 20% to
> 25%"
>
> Just a minor omission there ......
>
>
> Barry Watzman wrote:
>
>> There have been 3 different battery systems used in laptops, NiCad, NiMH
>> and Lithium. Some of the advice still being given out (on systems with
>> Lithium batteries) is old, outdated advice that was only applicable to
>> NiCad (the oldest and by far the worst of the 3 technologies).
>>
>> All of the batteries do have a limited number of discharge cycles. The
>> number is typically in the range of 300 to 500 for lithium batteries.
>> It's not totally clear to me how this applies to partial cycles.
>>
>> The "full charge and discharge" advice only applies to NiCad batteries.
>> There is no need to do this for Lithium batteries and it may even be
>> harmful. Lithium batteries last longest if they are discharged below
>> about 20% to 25%. [Some people say they should also not be charged above
>> about 95%]. Manufacturers recommend long term storage of lithium
>> batteries at about half-charge, but personally I've stored them fully
>> charged and not seen significant adverse effects (and I have quite a few
>> 10-year old lithium batteries that will still run a laptop for 2 hours).
>>
>>
>> Bobby wrote:
>>
>>> What is the best way to use a new laptop?
>>>
>>> The manufacturer points out that the battery has a limited number of
>>> recharge cycles and recommends that I fully charge and discharge the
>>> battery every time I use it - but that's not practical.
>>>
>>> Most likely I will use the battery for an hour or two and then connect
>>> it to the mains supply. Is that bad for the battery?
>>>
>>> Also, what sort of activity drains the battery most? Is there a website
>>> which lists this?
>>>
>>> Cheers.
>>>
>>> Bobby
>>>

 

[Guest]

Archived from groups: comp.sys.laptops (More info?)

Bobby wrote:

> I was advised the fully charge and fully discharge the battery when its new.
> Is that advice sound?

My Li Ion battery came fully charged from Dell.. I thought that was
strange, but it's probably part of their pre-shipment testing. Has
anyone else ever received a laptop battery fully charged out of the box?

 

[Guest]

Archived from groups: comp.sys.laptops (More info?)

Compared to NiCad, Lithium batteries do not have the "memory effect",
and don't need to be fully chaged/discharged (which was related to the
memory effect). However, almost everyone advises to do a full charge,
then a nearly full discharge (but not below about 20%), then a recharge
on the first use of a new lithim battery. I don't have any experience
to either refute or support that, but it's a nearly universal
recommendation.

There is certainly nothing wrong with cycling the battery (substantial
discharge & recharge), that is, indeed, the expected application. The
number of cycles is limited and finite, but moderately large (hundreds).



Bobby wrote:

> Thanks for this Barry.
>
> Your advice appears to be consistent with something else I read - the Li Ion
> batteries do not suffer from the memory effect.
>
> So it sounds to me that the "normal" full charge/partial discharge cycle
> (which is the natural way to use a laptop i.e. connected to the main most of
> the time but occasionally used on the battery for an hour or two) is best
> for these batteries?
>
> I was advised the fully charge and fully discharge the battery when its new.
> Is that advice sound?
>
> Bobby
>
> "Barry Watzman" <WatzmanNOSPAM@neo.rr.com> wrote in message
> news:42763BF0.4040507@neo.rr.com...
>
>>Ooops. "Lithium batteries last longest if they are discharged below about
>>20% to 25%" should read "if they are NOT discharged below about 20% to
>>25%"
>>
>>Just a minor omission there ......
>>
>>
>>Barry Watzman wrote:
>>
>>
>>>There have been 3 different battery systems used in laptops, NiCad, NiMH
>>>and Lithium. Some of the advice still being given out (on systems with
>>>Lithium batteries) is old, outdated advice that was only applicable to
>>>NiCad (the oldest and by far the worst of the 3 technologies).
>>>
>>>All of the batteries do have a limited number of discharge cycles. The
>>>number is typically in the range of 300 to 500 for lithium batteries.
>>>It's not totally clear to me how this applies to partial cycles.
>>>
>>>The "full charge and discharge" advice only applies to NiCad batteries.
>>>There is no need to do this for Lithium batteries and it may even be
>>>harmful. Lithium batteries last longest if they are discharged below
>>>about 20% to 25%. [Some people say they should also not be charged above
>>>about 95%]. Manufacturers recommend long term storage of lithium
>>>batteries at about half-charge, but personally I've stored them fully
>>>charged and not seen significant adverse effects (and I have quite a few
>>>10-year old lithium batteries that will still run a laptop for 2 hours).
>>>
>>>
>>>Bobby wrote:
>>>
>>>
>>>>What is the best way to use a new laptop?
>>>>
>>>>The manufacturer points out that the battery has a limited number of
>>>>recharge cycles and recommends that I fully charge and discharge the
>>>>battery every time I use it - but that's not practical.
>>>>
>>>>Most likely I will use the battery for an hour or two and then connect
>>>>it to the mains supply. Is that bad for the battery?
>>>>
>>>>Also, what sort of activity drains the battery most? Is there a website
>>>>which lists this?
>>>>
>>>>Cheers.
>>>>
>>>>Bobby
>>>>
>
>
>

 

[JF]

Archived from groups: alt.comp.hardware,comp.sys.laptops,microsoft.public.windowsxp.general,microsoft.public.windowsxp.hardware,uk.comp.sys.laptops (More info?)

X-No-Archive: yes
In message <3dm8mhF6qv4hhU1@individual.net>, Bobby
<bobby@aventuremail.com> writes

>Also, what sort of activity drains the battery most? Is there a website
>which lists this?

Loading and running Windows! I use a DOS-based word-processor for using
my laptop on the move when there isn't a handy power station outlet
socket to hand. Not entering WIN at the prompt means that a charge will
last several days instead of several hours. I think we've become so
obsessed with Windows sodware that we've forgotten what excellent
non-Windows software there is around. I even found USB2 drivers on the
Jumbo website, and I use Goldenhawk's (Jeff Jarold) DVD/RW/CD software
to write CD-ROMs.

--
James Follett. Novelist. (G1LXP) http/www.jamesfollett.dswilliams.co.uk
"Return of the Eagles", the last book in James Follett's 'Eagles' trilogy
published by Severn House, London & New York, Dec 2004

 

[Guest]

Archived from groups: alt.comp.hardware,comp.sys.laptops,microsoft.public.windowsxp.general,microsoft.public.windowsxp.hardware,uk.comp.sys.laptops (More info?)

JF wrote:
> X-No-Archive: yes
> In message <3dm8mhF6qv4hhU1@individual.net>, Bobby
> <bobby@aventuremail.com> writes
>
>> Also, what sort of activity drains the battery most? Is there a
>> website which lists this?
>
> Loading and running Windows! I use a DOS-based word-processor for
> using my laptop on the move when there isn't a handy power station
> outlet socket to hand. Not entering WIN at the prompt means that a
> charge will last several days instead of several hours. I think we've
> become so obsessed with Windows sodware that we've forgotten what
> excellent non-Windows software there is around. I even found USB2
> drivers on the Jumbo website, and I use Goldenhawk's (Jeff Jarold)
> DVD/RW/CD software to write CD-ROMs.
>
> --
> James Follett. Novelist. (G1LXP)
> http/www.jamesfollett.dswilliams.co.uk "Return of the Eagles", the
> last book in James Follett's 'Eagles' trilogy published by Severn
> House, London & New York, Dec 2004

True, Word for Dos is almost as good as Winword once you master the command
structure, and loading it is so quick you can have a letter typed whilst
WinXP is booting!

Dennis.


--
Digital Photo-charts fo all UK areas.
Remove 'nospam' to reply.

 

[Guest]

Archived from groups: alt.comp.hardware,comp.sys.laptops,microsoft.public.windowsxp.general,microsoft.public.windowsxp.hardware,uk.comp.sys.laptops (More info?)

In article <FQPzSGDysldCFwLw@marage.demon.co.uk>, JF
<jf@NOSPAMmarage.demon.co.uk> writes
>X-No-Archive: yes
>In message <3dm8mhF6qv4hhU1@individual.net>, Bobby
><bobby@aventuremail.com> writes
>
>>Also, what sort of activity drains the battery most? Is there a website
>>which lists this?
>
>Loading and running Windows! I use a DOS-based word-processor for using
>my laptop on the move when there isn't a handy power station outlet
>socket to hand. Not entering WIN at the prompt means that a charge will
>last several days instead of several hours. I think we've become so
>obsessed with Windows sodware that we've forgotten what excellent
>non-Windows software there is around. I even found USB2 drivers on the
>Jumbo website, and I use Goldenhawk's (Jeff Jarold) DVD/RW/CD software
>to write CD-ROMs.
>
Do you have a link for this Jumbo website? My Googling overwhelmed me!

Regards
--
Roger Hunt

 

[JF]

Archived from groups: alt.comp.hardware,comp.sys.laptops,microsoft.public.windowsxp.general,microsoft.public.windowsxp.hardware,uk.comp.sys.laptops (More info?)

In message <XJkDGIAMModCFwZj@carewg.demon.co.uk>, Roger Hunt
<x@carewg.demon.co.uk> writes

>>>Also, what sort of activity drains the battery most? Is there a website
>>>which lists this?
>>
>>Loading and running Windows! I use a DOS-based word-processor for using
>>my laptop on the move when there isn't a handy power station outlet
>>socket to hand.
>> I even found USB2 drivers on the
>>Jumbo website, and I use Goldenhawk's (Jeff Jarold) DVD/RW/CD software
>>to write CD-ROMs.
>>
>Do you have a link for this Jumbo website? My Googling overwhelmed me!

Apologies. It's http/www.jumbo.com/

I haven't looked at it for some time. There were pages of DOS drivers.

 

[Guest]

Archived from groups: comp.sys.laptops (More info?)

I contest the contention that a laptop could run "for days" no matter
what software you were running. If the laptop is in use, the screen
backlights and the hard drive motors will be running. A laptop running
windows will typically run for 2-3 hours on a battery charge. The most
that you could possibly, in the most extreme case hope for with any
software change of any kind (but with the laptop still on and actually
being used in a useful manner) would be to double or triple that, but I
would guess that you'd be lucky to get 20% to 40% more time.

I think that this is just "MS Bashing".


JF wrote:

> In message <XJkDGIAMModCFwZj@carewg.demon.co.uk>, Roger Hunt
> <x@carewg.demon.co.uk> writes
>
>>>> Also, what sort of activity drains the battery most? Is there a website
>>>> which lists this?
>>>
>>>
>>> Loading and running Windows! I use a DOS-based word-processor for using
>>> my laptop on the move when there isn't a handy power station outlet
>>> socket to hand.
>>> I even found USB2 drivers on the
>>> Jumbo website, and I use Goldenhawk's (Jeff Jarold) DVD/RW/CD software
>>> to write CD-ROMs.
>>>
>> Do you have a link for this Jumbo website? My Googling overwhelmed me!
>
>
> Apologies. It's http/www.jumbo.com/
>
> I haven't looked at it for some time. There were pages of DOS drivers.

 

[Guest]

Archived from groups: comp.sys.laptops (More info?)

Barry Watzman wrote:
> I contest the contention that a laptop could run "for days" no matter
> what software you were running. If the laptop is in use, the screen
> backlights and the hard drive motors will be running. A laptop running
> windows will typically run for 2-3 hours on a battery charge. The most
> that you could possibly, in the most extreme case hope for with any
> software change of any kind (but with the laptop still on and actually
> being used in a useful manner) would be to double or triple that, but I
> would guess that you'd be lucky to get 20% to 40% more time.
>
> I think that this is just "MS Bashing".

DOS is made by MS too remember?

 

[Guest]

Archived from groups: alt.comp.hardware,comp.sys.laptops,microsoft.public.windowsxp.general,microsoft.public.windowsxp.hardware,uk.comp.sys.laptops (More info?)

In article <y+5e5$AolrdCFwOH@marage.demon.co.uk>, JF
<jf@NOSPAMmarage.demon.co.uk> writes
>In message <XJkDGIAMModCFwZj@carewg.demon.co.uk>, Roger Hunt
><x@carewg.demon.co.uk> writes
>
>>>>Also, what sort of activity drains the battery most? Is there a website
>>>>which lists this?
>>>
>>>Loading and running Windows! I use a DOS-based word-processor for using
>>>my laptop on the move when there isn't a handy power station outlet
>>>socket to hand.
>>> I even found USB2 drivers on the
>>>Jumbo website, and I use Goldenhawk's (Jeff Jarold) DVD/RW/CD software
>>>to write CD-ROMs.
>>>
>>Do you have a link for this Jumbo website? My Googling overwhelmed me!
>
>Apologies. It's http/www.jumbo.com/
>
>I haven't looked at it for some time. There were pages of DOS drivers.

I must confess that I was too dim to try typing in www.jumbo.com!
Hey-ho.
Thanks for that - always good to have these resources handy.
--
Roger Hunt

 

[Guest]

Archived from groups: comp.sys.laptops (More info?)

"Barry Watzman" <WatzmanNOSPAM@neo.rr.com> wrote in message
news:42765783.60604@neo.rr.com...
> Compared to NiCad, Lithium batteries do not have the "memory effect",
> and don't need to be fully chaged/discharged (which was related to the
> memory effect). However, almost everyone advises to do a full charge,
> then a nearly full discharge (but not below about 20%), then a recharge
> on the first use of a new lithim battery. I don't have any experience
> to either refute or support that, but it's a nearly universal
> recommendation.
>
> There is certainly nothing wrong with cycling the battery (substantial
> discharge & recharge), that is, indeed, the expected application. The
> number of cycles is limited and finite, but moderately large (hundreds).
>

You can often find what to do. but not why to do it.

The first time you use a Lithium battery, the advise is to discharge it
until the monitor circuit cuts it off. This is not for the benefit of the
battery itself, but to calibrate the charge monitor circuit. This should be
repeated every few months.

It makes no difference how far you discharge a lithium battery (as long as
you don't overdo it). You strike 15-20% of its capacity for every 100
charge/discharge cycles. To clarify: that's 100 charge and discharge where
it's fully discharged every time. Or 200 cycles where it is only 50%
discharged or any combination and permutation thereof.

There is also a time penalty. Generally a battery loses 20% of its capacity
for every year it is fully charged and stored at 25 Celcius. Lower
temperatures (*NOT* below zero Celcius), it lasts longer. Lower charge, it
lasts longer. If not used, they are best stored at 40% charge in a fridge.

Although Lithium bateries offer the highest energy capacity for size and
weight of any currently available technology, they also have by far the
shortest life,

Incidentally, Nickel Cadmium batteries do not have (and never have) had a
'memory effect'. This was something dreampt up by the marketing men trying
to persuade us to buy the much more expensive (at the time) Nickel
Metal-Hydride batteries. The ironic part is that Ni-MiH batteries do suffer
from a phenomenon that appears to be similar to 'memory effect' called
voltage depression. The belief in the memory effect is a symptom of an
unrelated problem that occurs in little used Ni-Cd cells (Nickel whisker
growth).

 

[Guest]

Archived from groups: comp.sys.laptops (More info?)

"Michael Lee" <gte980p@prism.gatech.edu> wrote in message
news:d560b3$gkd$1@news-int.gatech.edu...
> Bobby wrote:
>
> > I was advised the fully charge and fully discharge the battery when its
new.
> > Is that advice sound?
>
> My Li Ion battery came fully charged from Dell.. I thought that was
> strange, but it's probably part of their pre-shipment testing. Has
> anyone else ever received a laptop battery fully charged out of the box?

All Lithium Ion batteries are shipped fully charged. That's how they come
off the production line. It also gives them the longest possible shelf
life.

 

[Guest]

Archived from groups: comp.sys.laptops (More info?)

Re:

Lithium bateries ... also have by far the
shortest life,

Nickel Cadmium batteries do not have (and never have) had a 'memory
effect'. This was something dreampt up by the marketing men trying to
persuade us to buy the much more expensive (at the time) Nickel
Metal-Hydride batteries.

Anyone on this board who has had any significant amount of experience
with both NiCad and Lithium batteries knows that both of those
statements are categorically wrong.

In fact, the "memory effect" was widely discussed decades ago, when
there was alternative to NiCad batteries.


Ye Electrik Fanne Clubbe wrote:

> "Barry Watzman" <WatzmanNOSPAM@neo.rr.com> wrote in message
> news:42765783.60604@neo.rr.com...
>
>>Compared to NiCad, Lithium batteries do not have the "memory effect",
>>and don't need to be fully chaged/discharged (which was related to the
>>memory effect). However, almost everyone advises to do a full charge,
>>then a nearly full discharge (but not below about 20%), then a recharge
>>on the first use of a new lithim battery. I don't have any experience
>>to either refute or support that, but it's a nearly universal
>>recommendation.
>>
>>There is certainly nothing wrong with cycling the battery (substantial
>>discharge & recharge), that is, indeed, the expected application. The
>>number of cycles is limited and finite, but moderately large (hundreds).
>>
>
>
> You can often find what to do. but not why to do it.
>
> The first time you use a Lithium battery, the advise is to discharge it
> until the monitor circuit cuts it off. This is not for the benefit of the
> battery itself, but to calibrate the charge monitor circuit. This should be
> repeated every few months.
>
> It makes no difference how far you discharge a lithium battery (as long as
> you don't overdo it). You strike 15-20% of its capacity for every 100
> charge/discharge cycles. To clarify: that's 100 charge and discharge where
> it's fully discharged every time. Or 200 cycles where it is only 50%
> discharged or any combination and permutation thereof.
>
> There is also a time penalty. Generally a battery loses 20% of its capacity
> for every year it is fully charged and stored at 25 Celcius. Lower
> temperatures (*NOT* below zero Celcius), it lasts longer. Lower charge, it
> lasts longer. If not used, they are best stored at 40% charge in a fridge.
>
> Although Lithium bateries offer the highest energy capacity for size and
> weight of any currently available technology, they also have by far the
> shortest life,
>
> Incidentally, Nickel Cadmium batteries do not have (and never have) had a
> 'memory effect'. This was something dreampt up by the marketing men trying
> to persuade us to buy the much more expensive (at the time) Nickel
> Metal-Hydride batteries. The ironic part is that Ni-MiH batteries do suffer
> from a phenomenon that appears to be similar to 'memory effect' called
> voltage depression. The belief in the memory effect is a symptom of an
> unrelated problem that occurs in little used Ni-Cd cells (Nickel whisker
> growth).
>
>