Prius V 2012: 12V dead Battery replacement

You could hold the fob up to the button per the owners manual. It will work without a good fob battery in that manner. Otherwise measure your 12v. A new battery should be 12v or better.

If someone played with the orange hv battery disconnect it may not be properly engaged with the last side push.

If there was a reversed polarity jump start attempt, things could be serious.

 

We assume you don't get a Ready indicator. True?

There were four suggestions and you addressed the first.

A new battery does not guarantee proper voltage. What is voltage at the engine fuse box jump point?

The high voltage disconnect is often not completely engaged with a sideways push.

A reversed polarity jump attempt will damage many fuses but the worst is a 125amp fusible link which can be tested by voltage measurement at a defined location.

Engine fuse box

 

Is it possible the FOB was exchanged? (Different FOB?)

 

ok now you have checked 2 out of 4, assuming the 12v was checked with an obd2 scanner.

Was really looking for the voltage at the front jump point but if it reads through a scanner it's probably ok. However I am not sure you checked the voltage downstream of the fuse box 125a fusible link to ensure a reverse polarity jump has not happened.

Plus no response on the hybrid battery disconnect referenced above.

Not all mechanics know enough about these cars to diagnose. A dealer may be the answer.

 

Do you have another Toyota vehicle with a SmartKey FOB?

 

OP, FWIW
If the battery is the only thing worked on and before the battery change all was "normal"...

Check your work.
1) You did not accidentally hook up the poss to neg and neg to pos terminals at any time?
2) When you hooked up the battery the headlights/ stereo/ doors and all were off and closed.
3) Cables are torqued securely to the battery.
4) If not mistaken there is a circuit board on the poss battery cable, with a fuse, look for damage and secure connection.
5) Perhaps easy is to remove/ reinstall - visually check - the fusebox and blade fuses.
6) As further info to your comembers here on Prius Chat, besides the no start, are all the other lights, door locks, alarms, and other functions all working correctly?
7) Finally, as a test, will the car start if a booster battery is hooked up?

Note: I have a "foggy" memory that some Toyota Software may be needed to recognize a new battery... other co-members may remember better.

Seems you have the car at a mechanic shop now? Post 8, RJ, makes a valid comment.

Lastly, sometimes Murphy Law/coincidences occur. The no start may not be related to your 12v battery change.
Good luck with your hunting