2018 Prius completely dead even after jumping. What now?

I bought my 2018 Prius 2 in 9/2018 in Houston. Since then, I've had a 12V battery issue in November 2019, got it replaced, and now have another issue.

When I started my car this time, it looked like the dashboard was schizophrenic. Parts of the dashboard turned on and off repeatedly, and a warning sign kept popping up about the 12V battery. Also, something around the engine area that kept clicking very rapidly, even after I turned off the car.

Now the car doesn't start at all even when I jump the 12V battery. I scheduled a maintenance check tomorrow but I can't even drive it out of my garage now. What are my options?

 

I went to the dealership and... they said there were no issues. My parasitic draw is low, the 12V seems to be in good condition.

I followed up with a call to Toyota Customer Experience Center. They basically said that my Prius is fine and to recommend that I drive the car at least once or twice a week to keep it in good condition.

I'm a little unsatisfied with that answer. Nowhere in the manual does it say that I have to drive it 1-2x a week and honestly, if that were the case I probably wouldn't have purchased a Prius. And in contrast, P.80 of my owner's manual (gen 4) states "be sure to drive the vehicle at least once every few months for at least 30 minutes or 10 miles" to charge the hybrid battery. This is the only mention of maintaining the Prius after periods of non-use

So is this normal behavior for a Prius? Or should I start looking into lemon laws?

 

Short story: The tow truck came and jumped it with a portable jumper. He put the negative on the battery terminal, which is different from what I did with the factory 12V. That seemed to work.

 

I followed the official "How to jump start a gen 4" video from Toyota USA by grounding the jumper cable on a metal plate instead of the negative terminal. This worked on the original factory battery, so I did not think of trying something different with the replaced battery.

I've started keeping my doors unlocked when I part to "deactivate" the SKS. I understand the 12V is a weak point, but 2 weeks seems like a reasonable period of time to keep a car parked.

 

Update:

I took it to another dealership for a second opinion (long story, but there's a mechanic I like and he diagnosed the first 12V failure when another mechanic said there wasn't one).

Long story short, he diagnosed a battery failure in this 12V as well (after another mechanic said there wasn't one). I got it replaced, so I'm on to my 3rd 12V after 18 months of owning this Prius! I'm thinking of leaving this one un-used for 2 weeks just to see if it's really the 12Vs or a defect with my car.

 

I'm at 18 months so I still have a little bit of room

Agreed! I just got my 12V replaced again (3rd one now). I'm going to leave it for 2 weeks and see what happens.

...maybe even 3 weeks, because I'm feeling dangerous.

• Dodgy 12V battery - The Toyota mechanic I trust tested it and it came back with a failure, so this might be it. I still think 2-in-a-row is strange and wonder if something else is wrong with my car.
• Aftermarket wiring, dealer installed options - I did not modify my car or ask for any additional installs. They might have installed something and forgotten to tell me about it, but the parasitic draw is at 30 milliamps so unlikely.
• My driving habits - Maybe, but if this is the case I'm blind to it. When I park I leave my interior lights off and turn off the headlights. I'm going to start leaving the doors unlocked when I park in my garage (deactivate SKS). Nothing's in my OBD2 port. I use this car for commuting to work (when I'm not quarantined). I average 67 MPG over the 11k miles on this car. Maybe the ICE isn't on enough? Let me know if I'm missing something.
• Mice infestation - Unlikely. How is the cabin air filter related to mice? The air filter is a little dirty but fine.
• Parasitic draw - dealership tested it at 30 milliamps. Probably fine.
• Atmospheric Pressure changes? The mechanic mentioned something about how storms here cause atmospheric pressure changes that affect the battery chemistry. I tried googling this and found nothing.

Thanks! I am documenting everything on the Toyota service history site.

 

Well, one was a "I don't know what to do next with this problem" and the other one was "Is this actually a problem or normal for a Gen 4?"

They just ended up having the same updates.