Make battery discharge while connected to AC (charging thresholds)

I found a solution for setting up charging thresholds in dom0 without installing anything there, here, which is

echo '85' | sudo tee /sys/class/power_supply/BAT0/charge_control_end_threshold
echo '75' | sudo tee  /sys/class/power_supply/BAT0/charge_control_start_threshold

I set that to 40 for start threshold and to 80 for end threshold.
Question: Do you know how to make battery discharge after it reaches the limit I set for battery to stop charging while connected to the AC? Ex. it reaches 80% and then discharge to 40% and start charging once again and all that while connected to the AC? Maybe something to edit in charge_behaviour in /sys/class/power_supply? Also when it reaches 80%, when I click battery icon, it says Waiting for discharge but it’s not discharging.

If you charge the battery up to the end threshold 80%, disconnect the AC, use the laptop for some time to discharge to e.g. 75%, connect the AC back then will it start charging up to end threshold 80% again or not?

No, it won’t. It says Waiting to discharge, too.

That’s expected behavior then.
If you’re wondering why your battery charge level stayed at 80% when fully charged - it’s because the battery self-discharge is very slow and battery charge level could be reduced to 79% only after a few days.