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S75D new - let stranded on the road due to 12V battery failure!

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I am a (VERY) happy owner of a brand new S75D black (creme vegan leather seats, AP).
This car is great and coming from an AUdi A6 3.0 TDI, this is just superior in every possible way. Performance is great, storage is ample, room for my 3 kids very positive, and long travel are indeed super calm and quiet thanks also to AP.

But, after just one month of ownership, I was coming back during the Christmas holiday from West part of Paris in France back to Switzerland. And after the lunch pause, with the car completely full, after 15mn of driving, suddenly, several error message appeared:
  • air suspension issue
  • front motor disable
  • 12 battery issue
The car asks me to park on the side of the road. And once in P, would refuse to change of gear and move further.

I pass on the wait of the road assistance, taxi to get a rental car with all the family and luggages to finish my trip back home. Eventually, with the wait, the computer shutdown and when we were taking our stuff away from the car, roughly 2 hours later, we could not open anymore the doors closed or the trunk. The 12V battery was completely depleted.

Tesla is working on it since yesterday so I am still waiting for info but how come that a 12V battery could fail so suddenly, without prior error message (load charge or whatever), just after 1 month of ownership?

Did someone already experience that?
 
There are couple manifestations of "12v" failure, with specific messages thrown for each. I am in the same boat, right now and am aware of two: actual 12v battery failure, and a more complicated failure that preserves the main battery but starves the smaller 12v. If it is your battery, something to the effect of 'replace 12v battery' should show up with fair warning. If not that, and you are seeing "12V Power Low - Car May Shut Down Unexpectedly" , you might want to try this thread: Immediate and fatal 12V battery failure

It doesn't look like a common issue, but does seem to be showing up a bit more lately.
 
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Reactions: Snerruc
It's not a really common thing, but it is such a noticeable problem that someone will always post about it on one of the forums. I'm mostly on the other forum on Tesla's website, and I've seen maybe two or three threads of this. It usually comes up within the first couple of weeks when there is some kind of early electronics failure, so it throws several random error messages and wants to shut the car down. It might be one of a few things, like a bad connection or failed chip of some kind. I know it's not fun when you are the one this happens to. But with any really complex machine, there may be some couple of things that were not right in the build or components that had a problem that only show up when the car starts getting used regularly. That is why large cruise ships have what they call the "shakedown cruise" for their first trip. It's a test period to try out all of the systems in normal operation to bring out any of these initial problems.

My car would not auto-present the door handles when I got it. Tesla sent a service ranger to fix it, and they found that it was a wiring harness in the door where the plastic clip that holds it together had broken, so it had pulled apart. They replaced that, and then I had no problems at all for the next year and a half. It's a bit hard to catch every thing in every system in the car with a few hours of inspection. I would put more importance on how well a company takes care of these issues.
 
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Reactions: skitown
There are couple manifestations of "12v" failure, with specific messages thrown for each. I am in the same boat, right now and am aware of two: actual 12v battery failure, and a more complicated failure that preserves the main battery but starves the smaller 12v. If it is your battery, something to the effect of 'replace 12v battery' should show up with fair warning. If not that, and you are seeing "12V Power Low - Car May Shut Down Unexpectedly" , you might want to try this thread: Immediate and fatal 12V battery failure

It doesn't look like a common issue, but does seem to be showing up a bit more lately.
This thread you link describes EXACTLY what I had. Exactly 100% the same.

Just to be sure we are speaking of the same thing, the thread speaks of HV / main pack and HVAC. It is the same?
For me, HVAC is the air conditioning / heating system. But "main pack" would be the main battery, right?
I imagine that Tesla will not be easily willing to change a brand new 75kW battery back without being able to reproduce the issue!!!

The issue is that, even if it was just 1 day and a half, they did not reproduce yet the issue and it could be anything so I am concern how they could isolate where the problem is coming from...
 
As for my 12V failure, it occurred on the X just 9 months after delivery. It may not happen often, but still a lot more often than other cars. In my opinion, the battery gets cycled and allowed to get low much too often. An engineer says that the most common type of failure is the 12V needs service message and says the average time to failure after that is 8-10 days so they want to change it as soon as they can. I bet there is a lot variability in that time frame. I don't really like these Sebang AGM batteries anyway. Yes, I know, higher cycle life is the main reason for selection, but there really needs to be a more reliable system in place.