If I were to install a 110v outlet through an inverter, hooked to the battery, how quickly am I gonna drain the 12v battery while the car is parked and the inverter is powering some heavy use items? The car would most likely not display is was turned to ‘on’ because I wouldn’t be sitting in the driver seat with my foot hitting the brake to power on the gear selector- yet does the car automagically charge the 12v even when it’s sitting by itself in park/ non driving mode?