... I have tried on my home level 2 charger. Exactly the same as KiwiMe said when I press the unlock button on plug the light around charging port starting flash green then I have to unlock doors either using fob or inside car doesn’t matter the doors are open already or not then I have 15 S to unplug the plug. ...
To be clear the "unlock" command from the fob, door handle button or inside button is all that's required to pause the charging for 15 seconds. Only in the case of the door handle button do the doors need to be locked first since the button only changes the
current state of the door locks, i.e. to unlocked. But, in all cases there is
no other subsequent action required and the charge plug should now be unlocked for that short period.
... However when I tried on another free public level 2 charger it is totally different:as long as I press the unlock button on plug charging stopped and light around charging port becomes white and I can remove the plug doesn’t matter the doors unlocked or locked. ...
When the port light is white it means that the EV is not seeing a charger connected, or if connected the charger is not making itself visible to the EV. The charger must have terminated the session due to the low current draw, under 0.5 kW. That might a specific feature the charger has because it is open to public misuse.
... As I mentioned The FLO level 2 charger is another story when I press unlock button on the plug the light did not change still solid green. I’ll try next time unlock my car see if I can remove the plug even light around the port is still solid green.
You won't be able to remove the plug while the port is solid green. Just to eliminate the possibility - next time try a
double click on the fob's unlock button.
Normally with AC chargers (Level 2 or Mode 2 and 3 as we call it down under) the EV is the boss, per standard J1772 and others derived from that. That's why many home wall chargers don't have any controls. The charger
can control what happens (by modulating the CP signal to the EV) but normally it would only indicate the maximum available current to the EV and do nothing else other than provide current (via relay closure) when the EV requests it.
I'd have to agree about the lack of a charge stop button in the EV. It does seem like a puzzling oversight and there have been many questions over the years about how to terminate a charge.
I'll just add that the situation differs somewhat for DC or "fast" chargers. In that case the interplay is more complex and charge sessions are normally ended gracefully by the charger. The EV
can terminate a charge session (as it does if you have a dash charge limit set) but the charger sees that as an error and then times out.