blog/data/2016-05-23-battery-stats.txt

   1 Title: Discharge rate estimate in new battery statistics collector for Debian
   2 Tags: english, debian
   3 Date: 2016-05-23 09:35
   4
   5 <p>Yesterday I updated the
   6 <a href="https://tracker.debian.org/pkg/battery-stats">battery-stats
   7 package in Debian</a> with a few patches sent to me by skilled and
   8 enterprising users.  There were some nice user and visible changes.
   9 First of all, both desktop menu entries now work.  A design flaw in
  10 one of the script made the history graph fail to show up (its PNG was
  11 dumped in ~/.xsession-errors) if no controlling TTY was available.
  12 The script worked when called from the command line, but not when
  13 called from the desktop menu.  I changed this to look for a DISPLAY
  14 variable or a TTY before deciding where to draw the graph, and now the
  15 graph window pop up as expected.</p>
  16
  17 <p>The next new feature is a discharge rate estimator in one of the
  18 graphs (the one showing the last few hours).  New is also the user of
  19 colours showing charging in blue and discharge in red.  The percentages
  20 of this graph is relative to last full charge, not battery design
  21 capacity.</p>
  22
  23 <p align="center"><img src="http://people.skolelinux.org/pere/blog/images/2016-05-23-battery-stats-rate.png"/></p>
  24
  25 <p>The other graph show the entire history of the collected battery
  26 statistics, comparing it to the design capacity of the battery to
  27 visualise how the battery life time get shorter over time.  The red
  28 line in this graph is what the previous graph considers 100 percent:
  29
  30 <p align="center"><img src="http://people.skolelinux.org/pere/blog/images/2016-05-23-battery-stats-history.png"/></p>
  31
  32 <p>In this graph you can see that I only charge the battery to 80
  33 percent of last full capacity, and how the capacity of the battery is
  34 shrinking. :(</p>
  35
  36 <p>The last new feature is in the collector, which now will handle
  37 more hardware models.  On some hardware, Linux power supply
  38 information is stored in /sys/class/power_supply/ACAD/, while the
  39 collector previously only looked in /sys/class/power_supply/AC/.  Now
  40 both are checked to figure if there is power connected to the
  41 machine.</p>
  42
  43 <p>If you are interested in how your laptop battery is doing, please
  44 check out the
  45 <a href="https://tracker.debian.org/pkg/battery-stats">battery-stats</a>
  46 in Debian unstable, or rebuild it on Jessie to get it working on
  47 Debian stable. :) The upstream source is available from <a
  48 href="https://github.com/petterreinholdtsen/battery-stats">github</a>.
  49 Patches are very welcome.</p>
  50
  51 <p>As usual, if you use Bitcoin and want to show your support of my
  52 activities, please send Bitcoin donations to my address
  53 <b><a href="bitcoin:15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b">15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b</a></b>.</p>