SUMMARY
Notebooks with configurable battery charge thresholds might discharge the battery if it is charged above the charge end threshold. This behaviour is useful for battery health on systems which are connected to a charger most of the time. Waiting for the battery self discharge after a full charge will take a long time at which the battery is charged to an unhealthy level.
The linux kernel's sysfs has no property to report this and the documentation for charge_control_end_threshold just specifies that charging will stop at this threshold. 
The battery applet should not confusingly suggest that power supply is is not powerful enough in this situation.

STEPS TO REPRODUCE
1. Charge the battery in an Apple silicon / asahi notebook to ~90% and connect a charger
2. Configure the charge limit stop threshold to 80%
3. look at the battery applet tool tip

OBSERVED RESULT
battery applet tool tip reports:
"Battery at 90%, plugged in but still discharging"
"The power supply is not powerful enough to charge the battery"

EXPECTED RESULT
"Battery at 90%, plugged in, discharging"
"Battery is configured to charge up to approximately 80%"
or simllar

SOFTWARE/OS VERSIONS
Linux/KDE Plasma: Linux 6.9.12 (Apple MacBook Pro, M2, 13-inch, 2022)
KDE Plasma Version: 6.1.3
KDE Frameworks Version: 6.4.0
Qt Version: 6.7.2