How long laptop battery should live ?

[Gary Gatten]

Ditto, pretty much mirrors what I read.  I forget the site, perhaps Panasonic? It was a cell manufacturer and published all sorts of data on different chemistry cells. Good info for my EV project too!  And yes, many people sell batteries as new who's cells are two years old!  Basically junk before you even get it.

----- Original Message -----
From: owner-freebsd-questions at freebsd.org <owner-freebsd-questions at freebsd.org>
To: Julian Fagir <gnrp at physik.tu-berlin.de>
Cc: freebsd-questions at freebsd.org <freebsd-questions at freebsd.org>
Sent: Tue Nov 23 16:26:42 2010
Subject: Re: How long laptop battery should live ?

On Tue, Nov 23, 2010 at 5:09 PM, Julian Fagir <gnrp at physik.tu-berlin.de>wrote:

> Hi,
>
> > I just looked into a batt for my daughters dell, her li-on lasted 14
> > months, now on "full" charge it only lasts 40 mins...  Terrible.  If you
> > can get 2 years out of a batt ur lucky.  I read some tech docs on li-on
> > cells; if you can store at 50% charge in the fridge and when in use don't
> > let it run down 100%.
> in my opinion, there's just one rule: Don't trust anybody.
> There are so many people who claim do be professionals, who say totally
> contrary things.
> On the one hand, there are many 'facts' which are falsely applied to
> LiIon-batteries which don't apply. On the other hand, there are many
> stories
> people remember from years long ago or from cheap notebooks without an
> 'intelligent' battery.
>
> Just to add another story from me: I have two batteries in my notebook, the
> one is always drowned to zero before the other one is being used (no, there
> are no possibilities to control that in my case). The one being drowned
> first, though not that often used that hard (appr once a week) was nearly
> dead after 1 1/2 years (6/23Wh), while the other one still has 23/27Wh.
>
>
> Regards, Julian
>


Li-Ion batteries tend to loose there imprint (the ability to hold a charge)
over time, the more the battery is discharged to 0%, the faster it will
loose that imprint. There really isn't squat you can do about it except buy
a new battery (and yes, make sure it is new, I bought a refurbed HP and the
*full* charge for it when I got it was 20% of it's original capacity (maybe
15-20 minutes), good enough in a pinch but that 20% lasted maybe a month)

As Julian stated ... there are too many people who claim to be professionals
(I'm not one of them), this are just what I have experienced and based on
what I have read. One resource I did find was
http://batteryuniversity.com/learn/article/how_to_prolong_lithium_based_batteries...
they seemed to at least present all the information available in a
logical order and it all made sense to me.

hth, C-
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