In the case of my Audi, the starter motor is 48v so the 12v system charges the 48v system enough to start.
In EVs the 12v system is used to power a contactor that connects the EV battery to the drive system. That’s the clicking sound you hear on power on and power off and another contactor can be heard clicking during charging.
In EVs the 12v system is used to power a contactor that connects the EV battery to the drive system. That’s the clicking sound you hear on power on and power off and another contactor can be heard clicking during charging.