Prius Left Running All Night - Result

So I am sure many of my blog readers are wondering:

Just what would happen if I left my Prius running all night?  Would it kill my battery?  Would my cart just auto shut off at some point?  Would it explode?  Would it make annoying noises and embarrass me in front of my neighbors?

Well, turns out that my wife and I found out last week.  Granted it wasn't on ALL night, but most of the day and evening.  It is so quiet it is very easy to think its off when getting out.

So, what did it do?  It was quiet for a lot of the time. I must have walked by the car 3 or 4 times and not noticed.  Our neighbor noticed late that night when all the lights were on inside and it was beeping.  She pounded on our door and let us know. 

We turned if off and went to bed.  Opted to check it out the next day.

The battery was still in the blue zone with 4 bars, but once we started running it it went to the low zone and the engine kicked in pushing power back to the battery.  After driving to the store for just a few minutes the battery was back to nearly full bars and everything was right with the world again.

Then we looked at her MPG.  She was previously at about 50MPG and was now at 43MPG.  So I figure that the car must have kicked the engine on several times to rejuice the battery, burning fuel.  Maybe a gallon or so?

At any rate, not sure what it would do if you ran out of juice and fuel.  But the bottom line is the car did ok for many hours.  I do wish it was smart enough to notice that it had been parked for hours and not moved and auto shut off or something. Would be a great setting to enable/disable.