[gwbas1c]

According to https://en.wikipedia.org/wiki/SAE_J1772, HomePlug is used in Europe. The article is otherwise rather ambiguous about how it's used in common chargers.

At least for the typical level 2 charger, the signaling is an analog square wave.

[devanl]

The typical level 2 charger doesn't have to use HomePlug, but most recent EVs will have a HomePlug modem in order to speak ISO15118 to negotiate the voltage during DC fast charging through the CCS1/2 connector.

The pilot pin that carries the square wave used for J1772 is common to both AC and DC charging, so it's possible for a level 2 charger to incorporate a modem and communicate with the EV.

In many situations it would be an unnecessary expense, but it may become more common even in level 2 chargers in the future since ISO15118 can be used to authenticate the car to the charger for plug-n-charge charging without needing a card or app to authorize the charge.