Cap charging at 80% from the Power Panel

[iamteedoh]

The power panel already reads charge-start-threshold and charge-end-threshold, and switches to "Charge limit / Holding" when a cap is active. There is no way to set one. Today that means editing sysfs by hand or installing TLP.

I added a CHARGE LIMIT section with two buttons, 80% and Full.

The part worth discussing is that nothing in the UI runs as root. The button writes a small config file, a systemd .path unit notices the change, and a privileged oneshot applies it to charge_control_*. No polkit action, no password prompt, no setuid helper, and the panel never touches sysfs itself.

Persistence needs hooks because the thresholds live in EC firmware rather than kernel memory: a udev rule for boot and hotplug, and the unit for resume. I also re-assert on a timer, which is belt and braces rather than something I can point at a specific failure for.

It has been running on my machine for a day. Happy to open a PR if there is interest, or to hear if you would rather solve the privilege hop a different way.

[iamteedoh]

Adding this thread here since it's related but nothing ever progressed with that so this should still be a valid request/discussion: #627 (comment)

[krsna1729]

Related: opened #13205 with a UPower D-Bus take on this (passwordless EnableChargeThreshold toggle in the power panel, default ON). Noting the sysfs-based open PRs #12177/#11792 as alternatives — happy to converge on whichever approach maintainers prefer.

[daviddelven]

+1 for this. Hardware data point in case it helps whichever implementation lands:

• ASUS Zenbook UX331UN, Omarchy 4.0.4, kernel 7.2.5-3-omarchy
• asus_wmi / asus_nb_wmi loaded, and /sys/class/power_supply/BAT0/charge_control_end_threshold is exposed (currently 100)
• No asusctl or TLP installed, so a panel toggle writing the sysfs threshold directly would cover this machine without extra packages.

[Paul-Bob]

If you want this before one of the PRs lands, I made Super Battery, a plugin that replaces the bar's battery popup with the same popup plus a Charge limit row.

On laptops with charge_control_end_threshold you pick 50–100% in steps of 5, so 80% is there. Turning the switch off charges to 100% again. On Lenovo IdeaPad and Legion it uses conservation mode instead.

It handles root differently from your design. The first time, a Set up button asks for your password through pkexec and installs one udev rule that gives your user's group write access to the charge limit files. After that the popup writes the threshold itself, with no prompt. It writes the limit again each time the shell starts, for firmware that forgets it on reboot.

It also has low battery alerts (with your own sounds) and an auto power saver.

Repo: https://github.com/Paul-Bob/omarchy-super-battery
Marketplace: https://plugins.omarchy.org/plugin.html?id=paulbob.super-battery