Battery "Charge Limit" doesn't work after reboot and constantly needs to be set manually

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1

Here’s the system info: paste. cachyos. org /p/070c5dd.log (I can’t paste actual links in here :roll_eyes: )

Mind you that I did the log after I manually set the charging limit to 55%.

When I startup my laptop while the charger is plugged in it shows the message:

Battery is configured to charge up approximately 55%

Yet it still goes over the charge limit up to 100%. And even when I manually set it up to 55% and plug the power adapter in it still charges the battery even if it’s above the threshold, only after it goes way bellow the charge limit (ca. 50%) and I plug it in it does start to work.

Why is that? Shouldn’t the “charge limit”- deamon run at startup automatically? And who determines the hysteresis limits for the charging? KDE Plasma or the laptop’s charging controller?

2

I have a Lenovo laptop and on mine, the “charge limit” setting is at BIOS-level and KDE merely configures that (or more precisely uses the Kernel’s facilities to do it). Thus the limit even holds when the laptop is off.

It looks like your Asus’ BIOS has similiar features (from your log):

Battery:
  ID-1: BAT0 charge: 47.9 Wh (73%) condition: 65.6/70 Wh (93.7%) volts: 11.88
    min: 11.88 model: ASUSTeK K6602ZC type: Li-ion serial: <filter> charging:
    status: discharging control: start: N/A end: 55% cycles: 119

Does yours allow you to set custom min/max levels or is it just a checkbox which says something like “limit battery charge to protect the battery”?

Can you try letting it fall below the configured 55% and then see if it kicks in correctly? Right now, your battery is at 73% which is above the charge limit.

For me, the new settings will only kick in if the battery is actually between my set min/max levels AND if I replug the charger whenever I change settings.

3

Depends on your hardware…

IIRC Some hardware only support 80%.

My thinkpad does support it and worked, but today I observe I have a charge limit at 80% and the battery charged at 100% :confused: and my battery isn’t discharging.
Ther was a text message “unplug the power supply to make it effective” warning when changing the threshold limit value.

There might be a regression.

4

Now that I have unplugged an replugged by laptop the battery is discharging.

cat /sys/class/power_supply/BAT0/charge_behaviour
[auto] inhibit-charge force-discharge
5

You might be right. I set it on 60% (which was supported by ASUS’s own Windows app) and it stopped charging once it reached 60%. I guess it doesn’t work with unsupported charge levels (60% and 80% were officially supported in Windows), but I might have to test it more thoroughly to really confirm that.

I’ll update my findings later.