Date: Fri, 20 Jul 2012 17:01:09 +0700 From: Erich Dollansky <erichfreebsdlist@ovitrap.com> To: Matthias Apitz <guru@unixarea.de> Cc: freebsd-current@freebsd.org, Lars Engels <lars.engels@0x20.net> Subject: Re: Script to monitor battery status on X220 Message-ID: <201207201701.10176.erichfreebsdlist@ovitrap.com> In-Reply-To: <20120720091356.GA31015@sh4-5.1blu.de> References: <201207201004.59451.erichfreebsdlist@ovitrap.com> <201207201545.23915.erichfreebsdlist@ovitrap.com> <20120720091356.GA31015@sh4-5.1blu.de>
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Hi, On Friday 20 July 2012 16:13:56 Matthias Apitz wrote: > El d=EDa Friday, July 20, 2012 a las 03:45:23PM +0700, Erich Dollansky es= cribi=F3: >=20 > > > ...=20 > > > Is it necessary to poll? Usually devd generates an event when the > > > battery status and/or percentage changes. Just read the events from > > > /var/run/devd.pipe. > > >=20 > > this is a good idea. I did not like this solution either but did not ge= t a better idea when I did it. >=20 > I wrote and used something similar for my netbook EeePC 900; it turned > out that the battery is not showing the remaining capacity in a linear this is also true on the X220. > way; the last 5% are 'consumed' in a few seconds, i.e. below 20% I > polled every 2 seconds; I did some tests until I ended at the 2%. There was always enough energy le= ft in the battery to restart the machine. I wonder anyway how they do it. I developed battery monitors a long time ag= o. As the voltage drop is not linear and the tolerances are very high. They= might calibrate each battery when it reaches certain levels. Erich
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