According to my OBDII reader, the battery drains about 0.8-1.3A when the car is idling (with gas engine off). This is without any AC, heater, fans, USB charging, seat heating or anything. Since the battery is at about 230V, we are talking about a 230W idling drain, which seems like a lot? I've actually clocked about 1m20s per percent of the HV battery lost when at a red light. Nothing crazy but not negligible for very long lights or if you're talking to a friend and you don't want to turn off/on the car.