2012 Prius v Won't Start

It is almost a certainty that the 12-volt battery is dead.
A "jump" to the 12-volt terminal in the under-hood fuse box would likely get you started.
EXTREME caution must be used - positive to positive, negative to nearby bolt in engine compartment.
BETTER to use a battery charger, 4 amp. max., for several hours first, then start normally.
Jumping without charging first may get you going, but the battery charging circuit is inadequate to restore the battery to full charge unless you'll be going on a multi-hour trip.

 

Probably a dead battery.

You must be very careful when you jump start a Prius. AAA should know how. But, your neighbor probably doesn't. You can fry $1,000+ worth of parts if it's done wrong. You need to keep the Prius in the "Ready" state for an hour or more to get a minimal charge after the jump.

Good Luck

 

The good news is that the 12V battery doesn't do the work of the cranking so you should be able to use wimpy jumper cables.

 

I have not had my 2012 v do it yet but know my wife killed her 2006 Prius by leaving on the dome light for more than a few hours. I have a battery jump pack for just such times which works well when you follow the instructions for jump starting the Prius.

 

You can unlock the door manually with the key inside your key fob. The truck can also be opened from inside (read the manual).

If this happens more than a few times you may want to replace the 12v battery. They don't like being fully discharged multiple times and can cause weird issues and lower mpg if they go mostly bad.