Thinkpad Legacy (Single battery) using tpsmapi

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 95-75 %, 85-60 %, and 85-40 % respectively.
  • The difference between end and start threshold cannot be less than 5%.

Dependencies

  • Thinkpad legacy depend on a kernel modules tp_smapi.
  • tp_smapi may be available as a package by your distro’s package-manager
  • Addition information about tp_smapi is available here: https://github.com/linux-thinkpad/tp_smapi

tp_smapi module is supported by a third party and this extension/author is not in any way responsible for the kernel module installation, bugs or damages.

Testing charging threshold using command-line

After installing tp_smapi below sysfs path will be available. For Thinkpad(Legacy) laptops the battery powersupply name could be BAT0 or BAT1. Hence charging threshold path could be one of the following and can be check using ls command.

ls-l /sys/devices/platform/smapi/BAT0/stop_charge_thresh
ls-l /sys/devices/platform/smapi/BAT0/start_charge_thresh

ls-l /sys/devices/platform/smapi/BAT1/stop_charge_thresh
ls-l /sys/devices/platform/smapi/BAT1/start_charge_thresh

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

For example:
If battery powersupply name is BAT0, to apply start threshold value of 55, end threshold value of 60, command would be.

Require root privileges

echo '55' | pkexec tee /sys/devices/platform/smapi/BAT0/start_charge_thresh
echo '60' | pkexec tee /sys/devices/platform/smapi/BAT0/stop_charge_thresh


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/devices/platform/smapi/BAT0/start_charge_thresh
cat /sys/devices/platform/smapi/BAT0/stop_charge_thresh


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

Condition for applying threshold

  • Accepted values for stop_charge_thresh : 6 - 100
  • Accepted values for start_charge_thresh : 2 - 96
  • stop_charge_thresh > start_charge_thresh
  • stop_charge_thresh - start_charge_thresh = 4


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

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

For example 1: Increase threshold

Laptops current threshold value is:
start_charge_thresh = 75
stop_charge_thresh = 80

User want to apply new threshold value of:
start_charge_thresh = 95
stop_charge_thresh = 100

Incorrect sequence

echo '95' > /sys/class/power_supply/BAT0/start_charge_thresh
echo '100' > /sys/class/power_supply/BAT0/stop_charge_thresh

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

Correct sequence

echo '100' | pkexec tee /sys/class/power_supply/BAT0/stop_charge_thresh
echo '95' | pkexec tee /sys/class/power_supply/BAT0/start_charge_thresh

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

For example 2: Decrease threshold

Laptops current threshold value is:
start_charge_thresh = 75
stop_charge_thresh = 80

User want to apply new threshold value of:
start_charge_thresh = 55
stop_charge_thresh = 60

Incorrect sequence

echo '60' | pkexec tee /sys/class/power_supply/BAT0/stop_charge_thresh
echo '55' | pkexec tee /sys/class/power_supply/BAT0/start_charge_thresh

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

Correct sequence

echo '55' | pkexec tee /sys/class/power_supply/BAT0/start_charge_thresh
echo '60' | pkexec tee /sys/class/power_supply/BAT0/stop_charge_thresh

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

Quick Settings


Gnome 43 and above Gnome 42

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