Yes, that is what I was thinking. If say a Leaf or Tesla has to power both the ECU and the BMS in order to charge, it might be significantly less efficient than if a GM vehicle could just bypass the ECU and let the charger communicate directly with the BMS.I would think it would more depend on what is or has to be powered up to accept the charge... Which is probably were Ladogaboy was going.
Also, maybe some Leaf owners can confirm, but it is my understanding that very few options are available in the car while it is actively quick charging. Again, possibly an issue of relying on the CAN bus to communicate with the charger? Just trying to get a better understanding of the differences between vehicles.