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Date:      Tue, 3 Jul 2012 21:28:24 +0700
From:      Erich Dollansky <erichfreebsdlist@ovitrap.com>
To:        Ian Smith <smithi@nimnet.asn.au>
Cc:        freebsd-acpi@freebsd.org, Natacha =?iso-8859-15?q?Port=E9?= <natbsd@instinctive.eu>
Subject:   Re: How can I help with thinkpad x220 issues?
Message-ID:  <201207032128.24837.erichfreebsdlist@ovitrap.com>
In-Reply-To: <20120703231540.I46641@sola.nimnet.asn.au>
References:  <20120523151357.GC97037@sigil.instinctive.eu> <201207031820.22657.erichfreebsdlist@ovitrap.com> <20120703231540.I46641@sola.nimnet.asn.au>

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Hi,

On Tuesday, July 03, 2012 08:51:33 PM Ian Smith wrote:
> On Tue, 3 Jul 2012 18:20:22 +0700, Erich Dollansky wrote:
>  > On Tuesday, July 03, 2012 03:34:36 PM Natacha Port=E9 wrote:
> [..]
>  > > > How did you get this value? No battery inserted? The range should =
be
>  > > > from 0 to 100.
>  > >=20
>  > > Indeed, I had no battery inserted. Years ago I took the habit of
>  > > removing the battery of laptops used for long amount of time on AC
>  > > (currently for my X220, that's 9h every workday), because keeping a
>  > > fully charged battery on AC used to kill it. However I admit I don't
>  > > know whether technology improved enough to mnake it a non-issue (or =
even
>  > > whether even by then it was actually an issue and not an urban legen=
d).
>  >
>  > As an engineer I would say that Lenovo would have done a real bad job=
=20
>  > if this makes still a significant difference.
>=20
> Nonetheless, it's worth discharging and recharging both NiMH and Li-ion=20
> batteries periodically.  If you do it once a week that's only 52 cycles=20
> per year; a small fraction of its design cycles, and unless you store it=
=20
> partially charged in a fridge, less usage than its 'shelf life' anyway.
>=20
this is true.

> Apart from not harming the battery - which is designed for daily cycling=
=20
> over 2 or 3 years - running it down past exhaustion now and again will=20
> recalibrate the battery's onboard coulomb counter to reflect capacity.
> At least when they were called IBMs, that was IBM's advice for Li-ion.
>=20
I did not know this but wondered how they do it.
> [..]
>  > > > > hw.acpi.battery.time: -1
>  > > > > hw.acpi.battery.state: 7
>  > > >=20
>  > > > I have 0 here.
>  > >=20
>  > > I have 2 when it's charging, and 1 when it's discharging.
>  >=20
>  > Ok, now I have the same. 1 and 2. But never 7. It seems that there=20
>  > are some secrets.
>=20
> No secrets in FreeBSD, just stuff you have to hunt for and figure out :)
>=20
> /usr/src/usr.sbin/acpi/acpiconf/acpiconf.c suggests hunting thus:
>=20
> smithi on t23% find /sys/ -exec grep -H ACPI_BATT_ {} \;
> [.. see usage in acpi_battery.c, acpi_{cm,sm}bat.c and acpi_machdep.c ..]
> /sys/dev/acpica/acpiio.h:#define ACPI_BATT_STAT_DISCHARG                0=
x0001
> /sys/dev/acpica/acpiio.h:#define ACPI_BATT_STAT_CHARGING                0=
x0002
> /sys/dev/acpica/acpiio.h:#define ACPI_BATT_STAT_CRITICAL                0=
x0004
> /sys/dev/acpica/acpiio.h:#define ACPI_BATT_STAT_NOT_PRESENT     0x0007
> /sys/dev/acpica/acpiio.h:#define ACPI_BATT_STAT_MAX             0x0007
> /sys/dev/acpica/acpiio.h:#define ACPI_BATT_UNKNOWN      0xffffffff /* _BS=
T or _BIF value unknown. */

Interesting. I did not get the idea. I must watch for the critical once the=
 battery is low.

>  > > > > $ sysctl dev.acpi_ibm
>  > > >=20
>  > > > I do not have anything with IBM or Lenovo.
>=20
> Is this a Thinkpad model that shows no benefits from loading acpi_ibm?

I just loaded it to veryfy. There is no difference between loaded and not l=
oaded. At least it does not do any harm. The sysctls also do not show up af=
ter being loaded.

Erich



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