LaTop battery care and life expectancy

[Bryan O'Neal]

Don't forget the issues with heat. the longer and higher the heat
exposure the shorter the battery life. Also for my primary laptop I
will remove the battery entirely if I am plugged in and intend to run
for a while. Doing so gives me years longer on one battery.

On 10/11/11, keith smith <klsmith2020 at yahoo.com> wrote:
>
> Thank you Joseph for take the time to explain all this to me.  I think I
> understand better.  Since my laptop runs without a batter if plugged in I
> assume I should only place the batter in my laptop when I plan to run it on
> batter power only.
>
> The battery has been out for several months and it is still at 80% .  Will
> it hurt the battery to let it self discharge for a few months?
>
> Thank again for this wealth of info and thank you to everyone who responded.
>
> ------------------------
>
> Keith Smith
>
> --- On Sun, 10/9/11, Joseph Sinclair <plug-discussion at stcaz.net> wrote:
>
> From: Joseph Sinclair <plug-discussion at stcaz.net>
> Subject: Re: LaTop battery care and life expectancy
> To: "Main PLUG discussion list" <plug-discuss at lists.plug.phoenix.az.us>
> Date: Sunday, October 9, 2011, 2:47 PM
>
> All Lithium-Ion batteries have similar issues and, in general, similar
> recommendations for care.
> Keep in mind, however, that different chemistries produce very different
> results, lead acid is very different from NiCd, NIMH, or LiIon.  Different
> batteries using the same general chemistry may still have very different
> specific chemistry to meet particular cost/current/charge/voltage
> characteristics. Lithium ion, for example, has at least 8 primary
> chemistries (e.g. LiPo, LiFe, LiZnCo, etc...), each with a hundred or more
> variations.
> Solar systems often use deep-cycle lead-acid because it is cheap, mature,
> and very rugged.  That makes comparing solar experience to laptops somewhat
> difficult.
>
> Some newer Lithium Ion batteries use new chemistry (e.g. Si cathodes in
> charge-carrier flexible polymer matrix to accommodate swelling during
> charge/discharge) to adapt to the issues below, but all still face the same
> challenges to a greater or lesser extent.
>
> 1) Lithium Ion involves actual absorption and release of Lithium atoms by
> anode and cathode.
>
> This means that there is physical stress on the battery elements, and over
> time this will damage the materials.  Deep discharge cycles and higher
> current drain will make these happen faster.
> Your cellphone battery has low current drain and long cycles, compared to a
> laptop, and will tend to last longer as a result.
> Letting your battery fully discharge before charging it will cause damage,
> but LiIon also has an explosive chemistry, so power management circuitry
> manages the battery, and turns off a phone when there is still about 20%
> charge left in the cell to mitigate this for cellphone batteries.
> The ideal usage is to charge at about 30% and not leave the cell above 70%
> for too long (see issue 2 for the reason).
>
> 2) Lithium Ion current limits are dependent on the Li mobility, which
> requires highly solvent electrolytes to permit high current usage.
>
> This means that the anode and cathode materials will dissolve in the
> electrolyte over time, and, because of the electrical potential between
> anode and cathode, will form whisker structures that eventually short across
> the gap between the electrodes.
> Leaving the cell fully charged for a long time (or constantly charging it
> when not in use) will encourage these whisker structures to grow because it
> maintains a higher potential between the electrodes.  This is why leaving a
> battery in a charger for a long time (months or years depending on the
> battery and charger) will eventually result in a dead battery, even though
> it was never really used.
> Modern charging circuitry could account for this by discharging the battery
> periodically, but laptops and other consumer-oriented devices generally do
> not in order to maintain immediate readiness for on-battery use while
> charging.
> The recommendation is to actually use the device powered by the battery from
> most of the time, and only add A/C power to recharge, when planning to
> disconnect in the near future, or when usage duration is reasonably expected
> to exceed battery life (even then starting on battery and adding A/C when
> charge drops below 50% often helps).  It's also best not to leave a laptop
> always connected to power, and only plug in when charging is actually
> needed.
>
>
> In the end, the reason a cellphone battery often lasts so much longer than a
> laptop battery (typically 2-3 times as many charge/discharge cycles) is more
> about the different power requirements of the two uses and the specific
> structure and chemistry choices made to match battery to load.
> Research is constantly advancing battery and other electrical energy storage
> technologies, so the performance one may expect for a given usage are
> constantly changing, and different manufacturers may use very different
> approaches to meet specific cost and performance criteria.  This makes
> comparing, or even predicting, battery life very difficult, to the point of
> being little more than a guess, so the best advice I know is to simply use
> the device in a reasonable manner, and keep an eye on the lifespan indicator
> via the battery information probe available in Linux so you have some
> advance warning when you'll need to purchase a new battery.
>
> ==Joseph++
>
> On 10/09/2011 01:22 PM, keith smith wrote:
>>
>>
>> I've had several laptops and battery longevity has always been an issue.�
>> Not how long it will run my laptop before completely discharging, but how
>> long it will be before that battery is no good.� What I do not understand
>> is why or how a battery can go bad from being in a laptop that is plugged
>> in and why there is a overcharging issue. �
>>
>> I have two frames of reference, maybe three.� My cordless phone battery
>> lasts for years.� I recently started researching solar power.� Seems some
>> think the battery's life is extended by not draining it and having a
>> constant change trickling into it.� One of the videos said the life of the
>> battery was in cycles.
>>
>> My cellular phone is 3 and a half years old.� My wife tends to forget to
>> charge her phone periodically and the battery discharges to the point the
>> phone shuts down.� We switch batteries because I keep mine charged for the
>> most part and rarely leave home because I work out of my house.
>>
>> The battery in my last laptop, about 8 years ago, went out in about 3
>> years.�
>>
>> I have removed the battery from my current laptop hoping to extend it's
>> life expectancy.� I rarely using my laptop away from my home office.� When
>> I do I try not to go on battery power, however the battery is being
>> charged at that point.
>>
>> My experience makes me wonder why my cellular battery can last 3 plus
>> years and might last 5 or 6 years, maybe longer. � And my laptop battery
>> is only good for 2 or 3 years.
>>
>> I've read a lot about laptop battery care, however it is still not clear
>> how to keep from wasting a perfectly good battery in just a few years .�
>> I'd really like to be able to buy a laptop and be able to use it for 5
>> years.� What is the best way to approach laptop batteries?
>>
>> Thank you for your help.
>>
>> ------------------------
>>
>> Keith Smith
>>
>>
>>
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