debcrafters-packages team mailing list archive

[Nick Rosbrook <2112342@xxxxxxxxxxxxxxxxxx>]

> This is my first bug report, and I may not have made the core problem
clear enough.

This is actually a very clear bug report IMHO. So thanks for that!

> The issue is not that the system shuts down too early — the issue is
that it doesn't shut down at all.

Right, that's not what I was suggesting. My points was that for *other*
users, performing the shutdown at 5% might be seen as taking action too
early. Right now, that's the stage where one gets a notification that
the battery is critically low, but it does not shutdown right away.

But, your points are well taken. Maybe these values should be more
conservative.

** Changed in: upower (Ubuntu)
       Status: Incomplete => Triaged

** Changed in: upower (Ubuntu)
   Importance: Undecided => Wishlist

** Tags added: dcr-incoming

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https://bugs.launchpad.net/bugs/2112342

Title:
  UPower default PercentageAction=2.0 is too aggressive for degraded
  batteries — suggest changing to 5.0%

Status in upower package in Ubuntu:
  Triaged

Bug description:
  Affected system:
  Laptop: Lenovo ThinkPad T490
  Ubuntu versions tested: Ubuntu 24.04 LTS and Ubuntu 25.04
  Battery condition: Moderate degradation (~36% capacity loss)

  upower:
    Installed: 1.90.7-1build1

  energy-full:         32.35 Wh
  energy-full-design:  50.5 Wh
  capacity:            64.06%

  On this system, when the battery level dropped to ~2%, the system
  attempted to perform a shutdown as configured by UPower default:

  PercentageAction=2.0

  However, due to the degraded state of the battery, the voltage dropped
  too rapidly at that level for the system to complete the shutdown
  properly. This resulted in a system freeze with a blinking Caps Lock
  LED, indicative of a kernel panic caused by power failure during a
  critical system operation.

  This issue occurred reliably and repeatedly on both Ubuntu 24.04 and
  25.04.

  Diagnosis:
  1. The battery has significantly reduced capacity (~64% of design).
  2. At 2% reported charge, there was insufficient residual energy to allow the shutdown process to complete.
  3. Increasing the threshold for the shutdown action to 5% resolved the issue completely.

  Solution:
  I edited the file /etc/UPower/UPower.conf and changed the following lines:

  PercentageLow=20.0
  PercentageCritical=10.0
  PercentageAction=5.0

  
  I also restarted the service:

  sudo systemctl restart upower

  
  After this change, the system reliably enters CriticalPowerAction when the battery reaches 5%, with no further freezes or panics.

  
  Suggested change to default UPower configuration:

  PercentageAction=5.0

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