You usually see a battery going when it is really cold and the car won't start but once jumped, it runs. Except in a 2004-2009 Prius. The 12V doesn't have to start the engine, just open up the circuits and power them until the electric motor starts the gas engine. The "your 12V is dying" symptom is bizarre. You get a message telling you to put the car in Park (it does that itself when you power the car off) when you power off and open the door. Not a very helpful message. or you have an electrical drain somewhere. If it dies while parked, something is pulling juice. Similar to when you forget to turn the lights off.
If the battery keeps dying, it might not be the battery
More than likely the alternator isn't alternating
That is so sad!!! Signalling a "turn" when you are driving and forget to turn it off is one thing but signalling a turn when you aren't even in the car???? I think I would disconnect the battery when done driving until needed again. Gets tiring jumping the car.
