Dead 12 V battery in my Model S Plaid

[CBGPE]

I took delivery on my Model S Plaid Thursday July 1. I have driven it about 400 miles. On Wednesday July 7 I went out to the car and it was completely inoperative. The car was at 70% charge.It was plugged into a Tesla home charging unit and could not be unplugged. I was able to follow the instructions in the owners manual up to the point of accessing the 12v battery. However the instructions on how to connect to it were totally wrong. The manual on line at least when I downloaded it was for the 2020 model not the 2021. Was able to figure out where to connect and get the car powered up and on a flat bed tow truck which Tesla sent for the car. It has been at the service center since Wednesday evening. Thursday morning they went out to look at the car and it worked normally. The engineers in Ca were called in on the problem No answers as to what happened. They still have the car.
Anyone else have this problem ?

 

[Tam]

...No answers as to what happened...

Brand new car 12V depletion could be:

1) Bad batch of brand new 12V battery. A simple replacement would take care of the issue. The Plaid is now equipped with 12V Lithium battery and not traditional lead-acid so we should expect much longer longevity than 400 miles.

2) Some issues have prevented the recharging of the brand new, good 12V lithium battery: Could be a bad DC-to-DC converter (from 400V to 12V DC)... In this case, if the cause is not fixed, replacing the 12V lithium battery would be a temporary fix until it runs down without being charged up automatically again.

 

[CBGPE]

Thanks for you comments. It could be anywhere in the 12 V system, From a simple bad connection or ground, a software issue, a problem with the charger for the 12 V system to a bad "12 V" lithium battery. What I can tell you is the instant a jumper battery was connected everything worked normally. I get the impression they have no idea what the problem is and despite the fact car seems fine now they don't want to let it go as they don't know if it will strand me again. I just ordered and am going to get a small lithium ion jumper battery to carry with me when I exit the car so I can get the car going again if need be.
So once the jumper battery is in hand I will take my chances.

 

[PCMc]

Bad DC-to-DC converter seems like expect you'd see a multitude of other functional issues with low voltage subsystems. The fact all of those worked as soon as the 12V was applied to the car suggests to me this would be unlikely.

It is also possible it is a problem with the 12V battery monitoring software that triggers the recharging the 12V battery when needed. If that's the case, then could explain why the want they car held for engineering investigation in case there is some edge case with this specific vehicle.

 

[ucmndd]

Welcome to Tesla’s unofficial Early Access program! Access to beta software and hardware is a perk of low-VIN ownership.

Your impression that they have “no idea what the problem is” is very likely spot-on, as your service center almost certainly has zero experience on the new cars.

Good luck

 

[Wol747]

Any idea of the manufacturer of the Li battery?

 

[CBGPE]

I go in today to have the 1/2 shafts swapped out on the Model X. Its first trip back to the Service Center since new !! 18 months ,14800 miles with no real issues.
I will see what they say today about the model S. They are planning to give me a loaner. IF they keep the Plaid until Wednesday the Service Center will have possession of the Plaid for more time than I BTW the car was a birthday present to myself.

 

[DerbyDave]

When you get your own Birthday presents, you get exactly what you want. Happy Birthday! I hope this issue is resolved quickly so you can continue to enjoy your new car!

 

[ZilWin]

Welcome to Tesla’s unofficial Early Access program! Access to beta software and hardware is a perk of low-VIN ownership.

Your impression that they have “no idea what the problem is” is very likely spot-on, as your service center almost certainly has zero experience on the new cars.

Good luck

LOL. You have no idea how correct you are. I worked in Tech support and field engineering for a company that designed and manufactured microwave communications equipment. Engineering would release product that was brand new and mostly undocumented at a service and support level. We would have to field calls, answer customer questions, and resolve issues without ever having seen the product. This syndrome is not exclusive to Tesla. In fairness, you'll never know how to break it until you get it in the hands of the customers.

 

[AmpedRealtor]

I took delivery on my Model S Plaid Thursday July 1. I have driven it about 400 miles. On Wednesday July 7 I went out to the car and it was completely inoperative. The car was at 70% charge.It was plugged into a Tesla home charging unit and could not be unplugged. I was able to follow the instructions in the owners manual up to the point of accessing the 12v battery. However the instructions on how to connect to it were totally wrong. The manual on line at least when I downloaded it was for the 2020 model not the 2021. Was able to figure out where to connect and get the car powered up and on a flat bed tow truck which Tesla sent for the car. It has been at the service center since Wednesday evening. Thursday morning they went out to look at the car and it worked normally. The engineers in Ca were called in on the problem No answers as to what happened. They still have the car.
Anyone else have this problem ?

Welcome to "Life with Tesla"! And when you call service after paying $140,000 for a 10 year old body style, you'll receive the same *****y treatment as those who paid 1/3 what you did and who still have newer bits. Elon Musk just doesn't know when to quit milking his customers, and his customers just can't stop bending over.

 

[KingRuth]

I go in today to have the 1/2 shafts swapped out on the Model X. Its first trip back to the Service Center since new !! 18 months ,14800 miles with no real issues.
I will see what they say today about the model S. They are planning to give me a loaner. IF they keep the Plaid until Wednesday the Service Center will have possession of the Plaid for more time than I BTW the car was a birthday present to myself.

I tried PMing you, but I can't since I am so new. Do you miss the z06 any? I was reading this post and saw your profile. I'm researching tesla's and wanted to hear your experience. Feel free to PM if you can.

 

[CBGPE]

I tried PMing you, but I can't since I am so new. Do you miss the z06 any? I was reading this post and saw your profile. I'm researching tesla's and wanted to hear your experience. Feel free to PM if you can.

The ZO 6 was fun. Very traction limited. 3rd gear roll ons had to be approached with circumspection and sometimes 4th gear as well. Handling was excellent.
No don't miss it technology marches on.
The Paid is way quicker, smooth quiet and predicable. Mine is midnight gray. The only way you can tell it is a little different are the tires and the small "Plaid" on the back. It is a sleeper. It blends in which is what you want if you want to avoid "unwanted attention"

 

[CBGPE]

DRUM ROLL PLEASE
The 12 V problem has been resolved.
Apparently there was a software problem in the Tesla Wall Charger that prevented the 12 V battery from being supported. My Model S was apparently the first car effected by the problem. A software update was sent to all the Plaids as they seem to be the only cars effected by the problem. My Plaid was the first one that my local service center in White Plains N Y has seen. I get the impression I have one of the first Plaids in the area.
BTW my Model X was also in for new 1/2 shafts. I requested a brake clean and lube. Mount Kisco did that at no charge. So far my service experience could not be called bad. The Model S Plaid is brand new and some bugs have to be expected.

 

[Wol747]

Glad it's been sorted - but I'm at a loss to see how the wall charger could affect the 12v battery? Surely that's just charged from the HV battery when it has a voltage drop.

 

[ucmndd]

Glad it's been sorted - but I'm at a loss to see how the wall charger could affect the 12v battery? Surely that's just charged from the HV battery when it has a voltage drop.

Either something was lost in translation or the explanation is pure BS.

 

[DerbyDave]

When I am plugged into the wall connector, and open a door, the wall connector starts supplying the car with small amounts of power to power the accessories. It stops shortly after I close the door. I assume if you have Sentry on, or the car needs some power while plugged in, it does not use the HV battery for everything. I think if this process is not working, the 12V battery could die causing the problem described in this thread

 

[CBGPE]

Glad it's been sorted - but I'm at a loss to see how the wall charger could affect the 12v battery? Surely that's just charged from the HV battery when it has a voltage drop.

Either something was lost in translation or the explanation is pure BS.

I was listening carefully but was not taking notes. So it's possible I missed something. I was also speaking to a local tech and not the engineering people as well so the info is second hand. They did say it was bizarre explanation and unique to the Plaid. They had 4 days to come up with the source and the solution so one might conclude it was difficult to figure out. Is it BS I can't say. IF it happens again I will let you know.

 

[ucmndd]

I assume if you have Sentry on, or the car needs some power while plugged in, it does not use the HV battery for everything.

It actually uses the 12v system for everything, and the HV battery charges the 12v as needed. Power from the wall is only used when the HV contactors are closed and the charging circuitry is powered - that happens when the car is on (door open), the climate control is on, or the HV battery is actually charging.

I think if this process is not working, the 12V battery could die causing the problem described in this thread

I agree on reflection that it’s possible there’s some interaction between the wall connector and car that keeps the car from being able to sense when the 12v is low and top it up. Or something to do with the different voltage characteristics upon discharge between lead acid and lithium batteries.

 

[brkaus]

Nissan Leaf used to have a problem where it would “forget” to charge the 12v if left plugged in. Once the main pack charged it would stop taking shore power and stop charging the 12v.

 

[DerbyDave]

It actually uses the 12v system for everything, and the HV battery charges the 12v as needed. Power from the wall is only used when the HV contactors are closed and the charging circuitry is powered - that happens when the car is on (door open), the climate control is on, or the HV battery is actually charging.


I agree on reflection that it’s possible there’s some interaction between the wall connector and car that keeps the car from being able to sense when the 12v is low and top it up. Or something to do with the different voltage characteristics upon discharge between lead acid and lithium batteries.

But, the HV battery is not charging when the door is open. I get 3 or 4 amps of juice from the wall connector. You think that dribble is going to the HV battery and not the 12 volt? Why?