Always have the car turned on before and while running the inverter, because the AGM battery in the Volt is not a high current battery like the one that is used to crank an ICE starter, and if you run it low or dead, the Volt will not start, just like an ICE car. The 380 volt DC to 12 volt DC inverter in the Volt can easily put out 150 amps if needed, so it can keep up with even a 1500 watt inverter, because it has a 175 amp fuse.
And, yes, if the big battery runs down, the ICE will start and keep it charged, but there is a timer in the car that shuts down the car after a couple of hours, but there is a work around, if you search for it.
And, yes, if the big battery runs down, the ICE will start and keep it charged, but there is a timer in the car that shuts down the car after a couple of hours, but there is a work around, if you search for it.