From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alexey Starikovskiy Subject: Re: kpowersave stuck at battery charging Date: Wed, 02 Jan 2008 19:18:33 +0300 Message-ID: <477BB959.1040207@gmail.com> References: <200801021248.55844.arvidjaar@mail.ru> <477B6AA5.5020803@gmail.com> <200801021610.45582.arvidjaar@mail.ru> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from nf-out-0910.google.com ([64.233.182.190]:26084 "EHLO nf-out-0910.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754023AbYABQSq (ORCPT ); Wed, 2 Jan 2008 11:18:46 -0500 Received: by nf-out-0910.google.com with SMTP id g13so347829nfb.21 for ; Wed, 02 Jan 2008 08:18:44 -0800 (PST) In-Reply-To: <200801021610.45582.arvidjaar@mail.ru> Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: Andrey Borzenkov Cc: hal@lists.freedesktop.org, linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org Andrey Borzenkov wrote: > On Wednesday 02 January 2008, Alexey Starikovskiy wrote: > >> Andrey Borzenkov wrote: >> >>> This is did not happen before; I am not sure right now what caused this >>> > (i.e. > >>> battery aging or some software change) nor whether this is >>> > kernel/HAL/kpowersave > >>> issue. >>> >>> kpowersave is stuck at assuming battery is loading and at 94%. Sysfs >>> > displays > >>> battery state as Full: >>> >>> >>> >> Frequent battery charging shortens lifetime of the battery, so some (may >> be all now) >> notebook manufacturers do not start charging battery until it discharge >> to some degree (~90%). >> > > I thought Li-Ion batteries do not have memory effect. Actually I remember to > have read recommendation to avoid deep discharges of Li-Ion battery, it was > adviced to charge it as often as possible. > IBM has advice to not re-charge battery until it discharged to 95%. It was implemented in their batteries/notebooks. There is no memory effect in Li-Ion batteries, there is only limited number of charge cycles -- about 1000 times, thus "as often as possible" is advice of the battery seller :) > >> It could be your case. Please try to discharge battery to, say, 89% and >> then check if it charges to the >> 100%. >> > > That is exactly the question - how do you compute 100%? As far as I can tell the > only possibility is - when battery stops charging. At this point you have to > assume battery is fully charged. > Last charge would be good reference. Think of the battery as constantly degrading resource. > I tried to discharge battery (it was around 78%) and plug AC in again. It went > on Charging until the same limit after that state changed to Full (well, in case > of ACPI battery we really only can state - not (dis-)charging, there is no > special Full state flag); kpowersave still believes battery is not fully > charged. Main interface shows 84% (no Charging) - tooltip states it is being > charged. > > So, that is the state of your battery. If you buy new one, it will go high again. Regards, Alex.