From owner-freebsd-mobile@FreeBSD.ORG Wed Oct 19 19:05:07 2011 Return-Path: Delivered-To: freebsd-mobile@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 241931065694 for ; Wed, 19 Oct 2011 19:05:07 +0000 (UTC) (envelope-from kob6558@gmail.com) Received: from mail-iy0-f182.google.com (mail-iy0-f182.google.com [209.85.210.182]) by mx1.freebsd.org (Postfix) with ESMTP id 863468FC26 for ; Wed, 19 Oct 2011 19:05:06 +0000 (UTC) Received: by iaky10 with SMTP id y10so3006844iak.13 for ; Wed, 19 Oct 2011 12:05:06 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type:content-transfer-encoding; bh=Ht8q5p/KQj6dazeiWritFxLDpOUtD1gtAj6hGiPrbws=; b=HH3mBppVcYhnIlBKTx0Az5bNLfu8vpXm/73ULET/0iw6uZ5JnlW4A8LPZJs1nKUdtn n2ltS1d9q+QHKr7Cv7q1oq8JwME/3P1YJezZCOBuika3hNjGobACTftocU46S/NtVukh X8HEF6uTpCgDwLWGzxf/xTnDBM9VgqGwdwFy4= MIME-Version: 1.0 Received: by 10.43.132.4 with SMTP id hs4mr13851878icc.57.1319051105249; Wed, 19 Oct 2011 12:05:05 -0700 (PDT) Received: by 10.231.36.69 with HTTP; Wed, 19 Oct 2011 12:05:05 -0700 (PDT) In-Reply-To: <4E9F0A0E.10009@paz.bz> References: <201110182335.15862.onyx@z-up.ru> <201110190844.17703.onyx@z-up.ru> <201110191713.02435.onyx@z-up.ru> <4E9F0A0E.10009@paz.bz> Date: Wed, 19 Oct 2011 12:05:05 -0700 Message-ID: From: Kevin Oberman To: Jim Pazarena Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Cc: freebsd-mobile@freebsd.org Subject: Re: Battery charge limiting X-BeenThere: freebsd-mobile@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Mobile computing with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 19 Oct 2011 19:05:07 -0000 On Wed, Oct 19, 2011 at 10:34 AM, Jim Pazarena wrote: > Kevin Oberman wrote, On 2011-10-19 8:49 AM: >> >> On Wed, Oct 19, 2011 at 6:13 AM, Dmitry Kolosov =A0wrote: >>> >>> Now the question is: how to discover EC/battery controller capabilities >>> of >>> such functions as holding battery about X% of full charge. >> >> Or to find the EC magic to turn off charging and create a daemon that >> monitors charge level nd turns charging off at about 80% and back on >> if it drops below 75%. > > renowned Tech Guy "Leo Laporte" and security expert "Steve Gibson" > had a discussion regarding lithium ion batteries, and Steve's findings > contradict these comments. > > I captured their podcast, and created a wav file (48Mb download) which > is available at ftp://ftp.haidagwaii.net/wav/ > specifically at: > ftp://ftp.haidagwaii.net/wav/lithium_ion_batteries_care-and-maintenance48= Mb.wav I have found Leo Laporte to be a very knowledgeable guy and I completely agree with most of what he is saying, but Lenovo is not suggesting the discharge of the battery, similar to how NiCads need to be treated. The issue is keeping batteries charged to 100% at all times. It's worth noting that the batteries in satellites, where long life is REALLY critical are only charged to 80% to keep them alive longer. See http://batteryuniversity.com/learn/article/how_to_prolong_lithi= um_based_batteries for a good explanation of the issue. It is discussed near the end o the article after the very telling Figure 4. I found severl other articles that contain similar information, but don't really provide much detail. --=20 R. Kevin Oberman, Network Engineer E-mail: kob6558@gmail.com