I worked in consumer electronics, but I can't fathom at all why having two parallel electric systems is though to be simpler than one. A backup battery, maybe,

I worked in consumer electronics, but I can't fathom at all why having two parallel electric systems is though to be simpler than one. A backup battery, maybe, but not a split system. > - Just because a batter is well suited to drive a car motor doesn't mean it's also well suited to power a AC, entertainment system etc. This has no basis whatsoever from electronics engineering standpoint. All these cars have something to provide regulated 12V from main battery already.