touch-packages team mailing list archive

[Matthew Paul Thomas <mpt@xxxxxxxxxxxxx>]

Mea culpa. It never occurred to me that a device might contain multiple
batteries of different capacities.

** Changed in: indicator-power (Ubuntu)
       Status: New => In Progress

** Changed in: indicator-power (Ubuntu)
     Assignee: (unassigned) => Matthew Paul Thomas (mpt)

-- 
You received this bug notification because you are a member of Ubuntu
Touch seeded packages, which is subscribed to indicator-power in Ubuntu.
https://bugs.launchpad.net/bugs/1430542

Title:
  Indicator doesn't use weighted average with different-sized batteries

Status in indicator-power package in Ubuntu:
  Triaged

Bug description:
  The indicator implements the spec:

    https://wiki.ubuntu.com/Power#Handling_multiple_batteries

  which stated:

    "Their percentages should be averaged."

  Apparently this was taken to mean the simple arithmetic mean, and not
  the weighted average (by the capacity of each battery).

    http://bazaar.launchpad.net/~indicator-applet-developers/indicator-
  power/trunk.15.04/view/head:/src/service.c#L1316

  shows:

    const double percent = sum_percent / n_batteries;

  This means that if one battery is twice as large as another, then
  after that battery is discharged, 50% would be reported.  I'd expect
  33%.

  The code needs to be fixed to reflect the more precise use of the word
  "average". <https://wiki.ubuntu.com/Power#multiple-batteries>: "Their
  percentages should be averaged, weighted by the capacity of each."

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/indicator-power/+bug/1430542/+subscriptions