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[Bug 1347539] Re: Abnormally high battery discharge rate on Lenovo T420


Presently I have kernel 3.13.0-48-generic installed (from the automatic
updates). With Bluetooth and WiFi off I am able to bring the discharge
rate down to 12 W/h. Although now I have battery lifetimes in line with
those I had with Ubuntu 12.04, there is still a long way to go to catch

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  Abnormally high battery discharge rate on Lenovo T420

Status in linux package in Ubuntu:

Bug description:
  I have upgraded from12.04 to 14.04 on a Lenovo T420 laptop
  (Corei7-2620M CPU @ 2.70GHz × 4 + Sandybridge Mobile). Whereas with
  12.04 the battery discharge rate would stay somewhere between 10 - 12
  W/h, with 14.04 it remains persistently over 30 W/h.

  The discharge rate came closer to normal after an upgrade by late May.
  But last week, apparently after an upgrade to linux-headers-generic,
  the abnormally high discharge rate is back.

  This thread at AskUbuntu details what I have tried (unsuccessfully) to
  identify the cause of this problem:


  ProblemType: Bug
  DistroRelease: Ubuntu 14.04
  Package: ubuntu-release-upgrader-core 1:0.220.2
  ProcVersionSignature: Ubuntu 3.13.0-32.57-generic
  Uname: Linux 3.13.0-32-generic x86_64
  ApportVersion: 2.14.1-0ubuntu3.2
  Architecture: amd64
  CrashDB: ubuntu
  CurrentDesktop: Unity
  Date: Wed Jul 23 11:15:26 2014
  InstallationDate: Installed on 2011-07-22 (1096 days ago)
  InstallationMedia: Ubuntu 10.10 "Maverick Meerkat" - Release amd64 (20101007)
  PackageArchitecture: all
  SourcePackage: ubuntu-release-upgrader
  Symptom: release-upgrade
  UpgradeStatus: Upgraded to trusty on 2014-05-02 (81 days ago)

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