From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pavel Machek Subject: Re: [POWER] battery calibration parameters from sysfs Date: Mon, 14 Dec 2009 22:22:57 +0100 Message-ID: <20091214212257.GA9213@elf.ucw.cz> References: <20091204104930.GA28625@sirena.org.uk> <20091207114825.GA26965@rakim.wolfsonmicro.main> <20091207165628.GA24981@rakim.wolfsonmicro.main> <20091213132413.GB1437@ucw.cz> <20091214121247.GB22388@rakim.wolfsonmicro.main> Mime-Version: 1.0 Return-path: Content-Disposition: inline In-Reply-To: <20091214121247.GB22388@rakim.wolfsonmicro.main> Sender: linux-embedded-owner@vger.kernel.org List-ID: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Mark Brown Cc: Linus Walleij , cbou@mail.ru, dwmw2@infradead.org, LKML , linux-embedded@vger.kernel.org, Brian Swetland , rpurdie@rpsys.net, lenz@cs.wisc.edu, Dirk@Opfer-Online.de, arminlitzel@web.de, Cyril Hrubis , thommycheck@gmail.com, linux-arm-kernel , dbaryshkov@gmail.com, omegamoon@gmail.com, eric.y.miao@gmail.com, utx@penguin.cz, zaurus-devel@lists.linuxtogo.org Hi! > > > I'm not sure how familiar you are with the issues surrounding trying to > > > do a voltage to charge mapping for a battery but it's much more complex > > > than a simple table if you want to get it accurate. There's a lot > > > of > > > Well... current zaurus kernels use _huge_ table that maps voltage to > > battery %... and that table is linear function :-(. > > > Do you have some papers on that? > > Something like "Measure Battery Capacity Precisely in Medical Design" > by Bernd Krafthoefer in Power Electronics Technology Jan 2005 might be > useful here. Well, that would really require extensive hardware modifications: it needs _way_ more accurate ADCs on battery for a start, and a way to generate huge load. -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html