From owner-freebsd-stable@FreeBSD.ORG Tue Sep 25 23:59:53 2012 Return-Path: Delivered-To: freebsd-stable@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id D6E9F106564A for ; Tue, 25 Sep 2012 23:59:52 +0000 (UTC) (envelope-from allbery.b@gmail.com) Received: from mail-qa0-f47.google.com (mail-qa0-f47.google.com [209.85.216.47]) by mx1.freebsd.org (Postfix) with ESMTP id 871F88FC1A for ; Tue, 25 Sep 2012 23:59:52 +0000 (UTC) Received: by qafi29 with SMTP id i29so4176702qaf.13 for ; Tue, 25 Sep 2012 16:59:51 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type; bh=nUCLBqzuHeh0zZM38CJcWSO9SXPs+jI1NyhYSzK71HE=; b=RYTEx17EQ4Ec5udKEWTrswTzPwyNI5RXbnaqw4C2Imm9Vu2CpU/XOLFLAyZMZ4Q6Bo 2Jew+OvOflzij6OREe3hIN1i4tkpn472fENLdkQlr4gTP5k1LRXLzOD/mXE1/koDX/iv hHgIMRkzbssSi5Xq0xc9vGVhFi+R5dJsFsf8z2g961kbLi1cqmFRE5+qoeyTEicp2ILv NUn9pIAhAO9PT9fWsdu1In9VZn5UNLYwVsU7CuFWAZUMYX36LuS3Sk7pxiNFRjc8XbsM 16yhlx8Ao2r/yDDzcqYi9I02k8gHpH7aJWhAfxFVCNd9FdXQRPfop0M2fMUeAfxqv3Yy WJvA== MIME-Version: 1.0 Received: by 10.229.137.84 with SMTP id v20mr12366759qct.70.1348617591337; Tue, 25 Sep 2012 16:59:51 -0700 (PDT) Received: by 10.49.95.230 with HTTP; Tue, 25 Sep 2012 16:59:51 -0700 (PDT) In-Reply-To: References: Date: Tue, 25 Sep 2012 19:59:51 -0400 Message-ID: From: Brandon Allbery To: Michael Schuh Content-Type: text/plain; charset=UTF-8 X-Content-Filtered-By: Mailman/MimeDel 2.1.5 Cc: FreeBSD Stable Subject: Re: battery state - hw.acpi.battery.life goes only down X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 25 Sep 2012 23:59:53 -0000 On Tue, Sep 25, 2012 at 7:43 PM, Michael Schuh wrote: > this wrong number seems persistent during a reboot. > i tested this, shortly. > the battery life after reboot was 97% with power supply plugged in all the > times. > > after a clean boot the system camed up with a battery.life of 97% ( power > supply plugged in :O ). > Sounds like normal lithium ion charger behavior to me; typically they won't kick in the charger until it reaches somewhere between 90-95% (depends on the device). This extends the useful life of the battery; raw lithium ion is just as (actually, more) prone to destruction via overcharging as other battery technologies. http://batteryuniversity.com/learn/article/charging_lithium_ion_batteriesdiscusses this. Note in particular: "A continuous trickle charge would cause plating of metallic lithium, and this could compromise safety." -- brandon s allbery allbery.b@gmail.com wandering unix systems administrator (available) (412) 475-9364 vm/sms