Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751276Ab0DPEPX (ORCPT ); Fri, 16 Apr 2010 00:15:23 -0400 Received: from ksp.mff.cuni.cz ([195.113.26.206]:41972 "EHLO atrey.karlin.mff.cuni.cz" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1750957Ab0DPEPV (ORCPT ); Fri, 16 Apr 2010 00:15:21 -0400 Date: Fri, 16 Apr 2010 06:15:09 +0200 From: Pavel Machek To: David Rees Cc: Mohamed Ikbel Boulabiar , linux-kernel@vger.kernel.org Subject: Re: Low-Level and Long-Term Battery Control Message-ID: <20100416041509.GB1552@elf.ucw.cz> References: <20100415180200.GA1443@ucw.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Warning: Reading this can be dangerous to your mental health. User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1839 Lines: 44 On Thu 2010-04-15 16:42:56, David Rees wrote: > On Thu, Apr 15, 2010 at 11:02 AM, Pavel Machek wrote: > >> For Laptops, it is better to extract the battery from the Laptop when > >> the computer will be on power for a long period. > >> I ask if the kernel can do such control without the user intention and > >> in an automatic way. > >> > >> Some BIOS provide to the user to select whether to block the battery > >> charging to 50% to make it stand for more time. > > > > Where have you seen that? > > I do recall that some older ThinkPads had a utility that would let you > determine what "empty" and "full" was by setting artificial limits. > It's well known that by keeping batteries from being fully > charged/discharged can significantly extend it's useful life although > you will suffer from shorter run-times. How sensitive a battery is to > this depends on it's exact chemistry, but all are affected by this to > some degree. > > For example, by keeping your battery from charging above 85% and below > 15% can increase the number of charge/discharge cycles a large > amount >From charging below 15%? > often on the order of 5-10 times more charge/discharge cycles - much > more than the 30% reduction in total capacity. Limiting to 25-75% > will help even more. I believe I've seen "don't charge above 85%", but "don't charge above 50%" is quite excessive... Anyway, this is done by smartbattery, not by OS. Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/