Thinkpad (Dual battery)

Capability

  • 3 presets: Full Capacity Mode, Balance Mode, and Maximum Life Span mode.
  • Default threshold values of these 3 preset modes are set at 100/95%, 80/75%, and 60/55%.
  • Each preset end threshold value can be customized between 100-80 %, 80-65 %, and 85-50 % respectively.
  • Each preset start threshold value can be customized between is 98-75 %, 83-60 %, and 83-40 % respectively.
  • The difference between end and start threshold cannot be less than 2%.

Dependencies

  • No dependencies required.
  • Thinkpad laptop that allows setting charging threshold are supported by mainline linux kernels.

Testing charging threshold using command-line

Charging mode can be set by using echo command in terminal.

For example:
To apply threshold on secondary battery (BAT1) with start threshold value of 55, end threshold value of 60, command would be.

Require root privileges

echo '55' | pkexec tee /sys/class/power_supply/BAT1/charge_control_start_threshold
echo '60' | pkexec tee /sys/class/power_supply/BAT1/charge_control_end_threshold


sudo also can be used in place of pkexec in the above commands as both sudo and pkexec can be use to run commands in root mode. To make use of polkit rules, the extension uses pkexec.

The current threshold value can also be read using cat command in terminal.

cat /sys/class/power_supply/BAT1/charge_control_start_threshold
cat /sys/class/power_supply/BAT1/charge_control_end_threshold

If charging threshold are applied successfully using above commands, the extension is compatible.

Condition for applying threshold

  • Accepted values for charge_control_end_threshold : 1 - 100
  • Accepted values for charge_control_start_threshold : 0 - 99
  • charge_control_end_threshold > charge_control_start_threshold


The sequence of applying threshold in command-line matters, as in whether to set charge_control_end_threshold first or the apply charge_control_end_threshold first.

The condition charge_control_end_threshold > charge_control_start_threshold must be fulfilled in order for charging threshold to apply. Threshold values will not be accepted if charge_control_start_threshold is less than charge_control_end_threshold

For example 1: Increase threshold

Laptops current threshold value is:
charge_control_start_threshold = 75
charge_control_end_threshold = 80

User want to apply new threshold value of:
charge_control_start_threshold = 95
charge_control_end_threshold = 100

Incorrect sequence

echo '95' | pkexec tee /sys/class/power_supply/BAT0/charge_control_start_threshold
echo '100' | pkexec tee /sys/class/power_supply/BAT0/charge_control_end_threshold

Since start_threshold is applied first charge_control_end_threshold (80) is less than charge_control_start_threshold (95), so the condition charge_control_end_threshold > charge_control_start_threshold is not fulfilled, hence charge_control_start_threshold wont be updated.

Correct sequence

echo '100' | pkexec tee /sys/class/power_supply/BAT0/charge_control_end_threshold
echo '95' | pkexec tee /sys/class/power_supply/BAT0/charge_control_start_threshold

Since end_threshold is applied first, charge_control_end_threshold (100) is greater than charge_control_start_threshold (75), so the condition charge_control_end_threshold > charge_control_start_threshold is fulfilled.

For example 2: Decrease threshold

Laptops current threshold value is:
charge_control_start_threshold = 75
charge_control_end_threshold = 80

User want to apply new threshold value of:
charge_control_start_threshold = 55
charge_control_end_threshold = 60

Incorrect sequence

echo '60' | pkexec tee /sys/class/power_supply/BAT0/charge_control_end_threshold
echo '55' | pkexec tee /sys/class/power_supply/BAT0/charge_control_start_threshold

Since end_threshold is applied first, charge_control_end_threshold (60) is less than charge_control_start_threshold (75), hence the condition charge_control_end_threshold > charge_control_start_threshold is not fulfilled. So charge_control_end_threshold wont be updated.

Correct sequence

echo '55' > /sys/class/power_supply/BAT0/charge_control_start_threshold
echo '60' > /sys/class/power_supply/BAT0/charge_control_end_threshold

Since start_threshold is applied first, charge_control_end_threshold (80) is greater than charge_control_start_threshold (55), so the condition charge_control_end_threshold > charge_control_start_threshold is fulfilled.

Quick Settings


Gnome 43 and above Gnome 42

Extension Preferences



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