From mboxrd@z Thu Jan 1 00:00:00 1970 From: pavel@ucw.cz (Pavel Machek) Date: Mon, 14 Dec 2009 22:22:57 +0100 Subject: [POWER] battery calibration parameters from sysfs In-Reply-To: <20091214121247.GB22388@rakim.wolfsonmicro.main> 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> Message-ID: <20091214212257.GA9213@elf.ucw.cz> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.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