My 2023 Prius surprisingly wouldn't start today.

it seems so obvious, especially after the gen 4 fiasco

 

The Gen 4 fiasco that exists only as an imagination in your mind.

 

and in priuschat

 

My Gen 4 Prius Prime's 12-V battery hasn't had a single issue in three years of my ownership; yet, I left my car undriven for up to over six weeks with a full Toyota Connected Services subscription at times.

 

You live in a mild climate.

The issue can easily only affect some cars or batteries. Not every Prius in the inverter recall had it die.

 

No, it gets very hot here sometimes. We had several weeks in a row of 100-plus-degree weather in the late summer of 2022, during which I owned my car. Heat is harder on a 12-V battery than cold.

 

Some of the comments in the Prime 2023 12V battery integrity on EV | PriusChat thread might be pertinent to this one.

 

My point is that your experience is anecdotal.

 

On the contrary, the battery failures reported on this forum are anecdotal.

Gen 4 (and Gen 5) Prius Prime has a dedicated battery multisensor to optimize its life. There is nothing in the car that would compromise the life of the battery as long as the owner uses the car properly; however, many owners don't. I posted over and over what I meant by that (not leaving the car plugged in for longer than overnight, having frequent long trips, not sitting in the car unless it is in the READY mode, also not having battery-draining accessory devices connected, etc.) So, yes, in that sense, the Prius Prime 12-V battery is not foolproof, as the car is demanding on the small 12-V battery (the owner's manual warns about the minimum-capacity requirement), and the owner must be aware of the 12-V battery precautions I listed.

Owning a car is challenging, and owning a BEV (or a PHEV) is even more challenging, as there is an extra level of complexity, which may further bother non-tech-savvy owners.

 

I wasn't commenting on the reported failures, just you using your individual experience as an example.

 

And the reported failures here are also individual experiences.

 

Why would having frequent long trips be using the car improperly?

Because I will go days with out driving I have since taken to connecting a battery maintainer that I leave plugged in when the vehicle is parked at home. I've also been making the effort to unplug the traction battery after it's charged.

Still the fact that the car can't be left plugged in until ready to go seems like an oversight on the design. I would have set up everything to use the AC connection when available for all the connected services and other features that drain the battery when it's not running. I would have also built in a battery maintainer that uses the AC power to maintain the 12V battery.

 

It is probably a safety thing by Toyota that they don't want to have the systems up and running when the car is off. Moreover, to have the systems up and running at all times could shorten their lifespan, as electrolytic capacitors and such have limited lifespans.

 

The days before I learned here about the cheap and effective battery monitors. Problem solved. I know where the battery is at, as much as I want to know. No more guessing.

 

2023 Prius Prime. My battery died on me this morning. Got it towed to Dealer. I charged it up full on Wednesday . I unplugged the charger right after full. I did not drive it all day Thursday. When I went to go to work this morning Friday the battery was dead. All the lights came on blinking and the wiper blades turned on but ran very slow. The tower had to charge my car up for 5 minutes before I could start it and drive out of the garage to but on the flat bed. Not sure what happened but the dealer said everything is checking out as good. They are keeping it overnight for observation.
I’m glad I left it overnight. Battery was dead again. They are putting a new battery in. Since closed Sunday I will have to pick up on Monday.