From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.9 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E8808C43382 for ; Wed, 26 Sep 2018 08:30:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C610F2083A for ; Wed, 26 Sep 2018 08:30:43 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=linaro.org header.i=@linaro.org header.b="hThJcxqb" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C610F2083A Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linaro.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727426AbeIZOm2 (ORCPT ); Wed, 26 Sep 2018 10:42:28 -0400 Received: from mail-lf1-f68.google.com ([209.85.167.68]:37860 "EHLO mail-lf1-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726401AbeIZOm2 (ORCPT ); Wed, 26 Sep 2018 10:42:28 -0400 Received: by mail-lf1-f68.google.com with SMTP id a82-v6so7086095lfa.4 for ; Wed, 26 Sep 2018 01:30:40 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc; bh=YPhaSuwgZIE6YSc6e7klVWPuc99XZubi/sRtM7ioCts=; b=hThJcxqbQu3AdSYpU2fhUYHFcYXj9fYgeyAV6P+cgvcpOwbyAm2JnQW2/p1oYS0RxX uDVTwNgmoMEkJ9wTxgg3ezt597jAVYH+6/xJX/9cAt1pRHR3DXcOrAmsg2G3dX9L0JHu cTfmFTqhDfgOKgq+eYig1EzqzeGPu+gZsRai4= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to:cc; bh=YPhaSuwgZIE6YSc6e7klVWPuc99XZubi/sRtM7ioCts=; b=ZsKECJS8Rxi9FMWP5aCVXU2cSRsaLo+cF/g/mOiRZfQ9RnqrXBydVweJCN+14idwZl OvONBlJ4stOQ+o35x+o4DZG1GXGdQAHZOUhDVzBNZEGLnQFBHdelDzuzVvKmw2xk+qqI C3Im7gOOPcdCylV+RuLkriBzwXZb+s1lNx+1rHJ9MMukCut2tAUxAGtwNhhZjB8rpyp6 3hGvoHndzhb02NeC33RTtwXMDhYqswANrOwTBKEyFVLF8wbOiyfrZ51ojtJA2OAlIog0 dHHehSvyfHKmgj2t+ib4rwMDDh3alrl4y2J8b9pTbWvZGNHSbUdIyU3Bif0OuqhcUbNd uLbQ== X-Gm-Message-State: ABuFfojm37l7vINmpnO4KUcmIw1W2izHNzchozukumTxAWiJj53lXH47 dnWzHM8zmeavp7v3RP9xO2KtQ5Mfr0wTVwfVfiKfug== X-Google-Smtp-Source: ACcGV61GzpURWOan1NVkZVIGcTmcmFbk9gsDZuJz9lfAwSUFa737VLEyRjReOXs1JJVLc375hiV8ReY1Lf6cYvOvAgg= X-Received: by 2002:a19:d189:: with SMTP id i131-v6mr3354027lfg.20.1537950639767; Wed, 26 Sep 2018 01:30:39 -0700 (PDT) MIME-Version: 1.0 Received: by 2002:a2e:95d7:0:0:0:0:0 with HTTP; Wed, 26 Sep 2018 01:30:39 -0700 (PDT) In-Reply-To: References: <358665e3f4f9ec105dc2f8a2dc6dd98dbe761fae.1537930252.git.baolin.wang@linaro.org> From: Baolin Wang Date: Wed, 26 Sep 2018 16:30:39 +0800 Message-ID: Subject: Re: [PATCH v2 1/4] power: supply: core: Introduce one property to present the battery internal resistance To: Linus Walleij Cc: Sebastian Reichel , Rob Herring , Mark Rutland , Linux PM list , "open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" , "linux-kernel@vger.kernel.org" , yuanjiang.yu@unisoc.com, Mark Brown , Craig Tatlor Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Linus, On 26 September 2018 at 16:00, Linus Walleij wrote: > On Wed, Sep 26, 2018 at 4:59 AM Baolin Wang wrote: > >> Introduce one property to present the battery internal resistance for battery >> information. >> >> Signed-off-by: Baolin Wang >> --- >> Changes from v1: >> - New patch in v2. > > I'm a bit confused by the physics in this patch. > > The internal resistance of a battery is not a constant in its life cycle, > this varies over the age of the battery, and the reason I thing is > chemical residuals accumulating on the anode and cathode inside > the battery and the energy storage medium aging. (Plus/minus my > ignorance about how batteries actually work.) Yes, you are right. The internal resistance can be affected by temperature or battery age or other factors. But our solution just uses one constant internal resistance to calculate OCV value to look up the capacity table when system boots on, in this case we do not need one more accuracy OCV, since we will calculate the battery capacity in future. So we just introduce one estimation constant internal resistance. > > AFAIK the fact that the internal resistance varies is of high > importance for people developing algorithms of battery capacity > and longevity. Such that some (hardware) capacity monitors go > to great lengths to measure with high precision the current > internal resistance of the battery for their algorithms. > > Sorry for making things more complex, but should it be named > "factory-internal-resistance-micro-ohms" or > "typical-internal-resistance-micro-ohms"? I am fine with this change. If Sebastian also agree with this change, I will fix. Thanks for your reviewing and comments. -- Baolin Wang Best Regards