echo 4000000 | sudo tee /sys/class/power_supply/bq25890-charger-0/constant_charge_voltage is the code to limit the max charge. After reboot it’s back to normal. If you chance the value, you also change the max amount. It does not start at 0, so keep steps little. To reverse it on code check the file /sys/class/power_supply/bq25890-charger-0/constant_charge_voltage_max - it should be 4208000. You either can write the number into the code above or copy paste it. Keep in mind, this is L5 specific.
Additional information:
The battery icon will always say you’re charging. But as soon as the red status led turns off, it does not charge anymore.