[ltp] X240: Sudden battery death

[Jochen Spieker]

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Henrique de Moraes Holschuh:
> On Tue, 08 Dec 2015, Jochen Spieker wrote:
>>=20
>> "Completely" as in "down to 5%, then the internal battery takes over". I
>> don't do a deep-discharge, of course.
>=20
> 5% is cutting it too close to deep discharge for Li-ION, especially becau=
se
> you cannot really trust it to be 5% (and not, say, 3% or less) as the "fu=
el
> gauge" can accumulate a lot of error very quickly.
>=20
> Keep it above 20% if you can.

How so? This laptop has an internal and an external battery. It
automatically starts to discharge the internal one when the external
battery goes down to 5%. I would be glad if I could change that
threshold. I bought additional warranty for the internal battery
(already down to 74%) so the more I make use of it the better. ;-)

>> As I said, I am aware that this is not the best way to treat a battery.
>> But I am still surprised by it becoming almost useless in less than two
>> weeks.
>=20
> Well, yes, that steep device breakdown curve is quite surprising.  If it =
is
> a 3-cell or 6-cell battery, it looks like each cell-group suffered a
> breakdown, close together in time...

6-cell.

> But if cycle_count returns zero, it might well be battery pack
> microcontroller failure (there's one inside the battery pack that is *NEV=
ER*
> powered down -- so, it is the one thing that must not have software bugs
> :p).

Interesting question. But it probably doesn't pay off to do a
post-mortem. I bought a new one and it works well (energy_full_design
71280mWh, energy_full 74800mWh). I even found it to be surprisingly
cheap (~65 EUR).

Also, this one now also shows 0 for cycle_count. The same holds true for
the internal battery. Maybe this is just a software issue (Debian/sid).

J.
--=20
I want to look younger than my friends so I will fight ageing as long as
I can.
[Agree]   [Disagree]
                 <http://www.slowlydownward.com/NODATA/data_enter2.html>

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