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Model 3 completely dead this morning. What an experience. [dead 12v]

Was going to drive my daughter to school this morning only to find my 2018 Model 3 COMPLETELY dead and unresponsive. The car was plugged into the wall charger overnight. Couldn't unplug either.

Contacted Tesla roadside assistance. They called a tow truck to have my car towed to the local service center.

Tow truck showed up, but since the car was in my very tight 1-car garage front end first, we had to figure out how to get it out of the garage. We got the plug removed from the front bumper, took a while but we eventually fished out the wires to open the frunk. We used his portable jumping device, nothing, frunk didn't open. He then moved his tow truck closer and use the extra long jumper cables and hooked those up to the wires, the frunk opened right up. We then got to the 12V batter and hooked up to those. Nothing. I contact Tesla and they said give it 20 min. We left it hooked up 30 min, still nothing. No response whatsoever. The tow truck driver said he's seen this happen before and that a Tesla tech neede to fix it. He then said he couldn't do anything more and had to go.

Tesla rep then arranged for a Tesla tech to come by. He checked everything and also stumped that the car was completely unresponsive to jumper cables attached to the 12V battery. He brought a spare 12V battery, so he swapped it out and as soon as he connected it, the car came back to life!!!!

He contacted a senior rep who went through the car's logs and said that just before the car died around 4am it was drawing about 3A from the 12V battery and that at some point the car shut itself down.

The car was plugged into the Tesla wall charger overnight and it DID charge the car yet the 12V battery died.

After a bunch more reviewing of logs they think it might be the Hannshow 9" display that for some reason could have been drawing power. The Hannshow display had been installed for almost a month now and I never had any problems before. The car never reported a problem with the 12V battery.

So, we're stumped. I disconnected the Hannshow display as a precaution, but I'm not sure that's the problem.

Anyone ever experience something like this?
 
Pretty much all companies will blame an aftermarket product

The fact that I’ve had a fair amount of problems with the Hansshow display other than this issue doesn’t inspire a ton of confidence

What’s really odd is that jumping the car from a tow truck as well as a portable jumper had zero effect on getting the car powered up. Only after removing the battery and putting a new one in got it working again. To further diagnose, we put the original battery back in and then it too worked just fine, so it’s not a dead 12V battery.

Our theory is that some system locked up and taking the battery out caused it to hard reboot and then it worked again

But who knows
 
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smatthew

Active Member
Jun 9, 2018
1,492
2,498
CA Bay Area
Pretty much all companies will blame an aftermarket product

The fact that I’ve had a fair amount of problems with the Hansshow display other than this issue doesn’t inspire a ton of confidence

What’s really odd is that jumping the car from a tow truck as well as a portable jumper had zero effect on getting the car powered up. Only after removing the battery and putting a new one in got it working again. To further diagnose, we put the original battery back in and then it too worked just fine, so it’s not a dead 12V battery.

Our theory is that some system locked up and taking the battery out caused it to hard reboot and then it worked again

But who knows
I'm not surprised. The car has modes where it is looking for the 12V battery to be disconnected completely (i.e. it was replaced) before it will reset.
 
Ugh. The Hannshow screen was completely removed including the harness 2 days ago.
My car was parked outside with about 70% charge. I just went to the car and it's completely dead yet again!

I'm on a chat with roadside assitance and they said teh following:

I was trying to see if there were any 12v Battery Alerts that I can see so I may cover for a 12v Battery Replacement, But there are none. It maybe the 12v Battery but without the Alerts present I am unable to provide a 12v Battery replacement. However I can provide a Tow to your nearest Tesla Service Center where the Vehicle will be inspected by a Tech and upon inspection and providing a diagnostic if the Tech determines it is a 12v issue they can proceed with assistance.
 

jjrandorin

Moderator, Model 3, Tesla Energy Forums
Moderator
Nov 28, 2018
14,577
18,637
Riverside Co. CA
Ugh. The Hannshow screen was completely removed including the harness 2 days ago.
My car was parked outside with about 70% charge. I just went to the car and it's completely dead yet again!

I'm on a chat with roadside assitance and they said teh following:

I was trying to see if there were any 12v Battery Alerts that I can see so I may cover for a 12v Battery Replacement, But there are none. It maybe the 12v Battery but without the Alerts present I am unable to provide a 12v Battery replacement. However I can provide a Tow to your nearest Tesla Service Center where the Vehicle will be inspected by a Tech and upon inspection and providing a diagnostic if the Tech determines it is a 12v issue they can proceed with assistance.

From reading what you said earlier, it sounds like you put the original 12v back in there and left it in there. You should have went with the replacement. Reports from cars around our age (mine is a dec 2018) is that these are lasting 2-3 years ish. If you put the original back in there and left it in there because "it was working so it wasnt the 12v", then you should have left the new one in there.

If you left the new one in there, then you have something else going on with the 12v. No idea what that would be, but your posts in this thread read like you swapped the original 12v back in there after testing with a new one.
 
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Definitely should have kept the new battery. The tech wanted to try to see if it was a reset that got it working or the battery. In the choas of diagnosing they didn't put the new battery back in.

I got the car jumped and drove it to the local service center. They checked the logs and it showed a ton of alerts. They did also check and that at times the car has an unexplained power draw on the 12V of approx 3A. I did ask them to put in a new 12V battery, they said would if it's defective.
 

jjrandorin

Moderator, Model 3, Tesla Energy Forums
Moderator
Nov 28, 2018
14,577
18,637
Riverside Co. CA
. I did ask them to put in a new 12V battery, they said would if it's defective.
Up to you, but a new one in our cars is like $129 "out the door". I would get a new one either way if I was you, either on their dime if they choose to cover it, or on yours if they say "it doesnt show it so its not covered".

I just had them replace my 12v on my dime since it was so relatively cheap, and there were so many 12v threads here for cars our age. I am certainly not in for "well tesla should......!" conversations on this topic, but just pointing out that I would replace it no matter what if I was in your shoes, whether they pay for it or I pay for it.
 
Definitely should have kept the new battery. The tech wanted to try to see if it was a reset that got it working or the battery. In the choas of diagnosing they didn't put the new battery back in.

I got the car jumped and drove it to the local service center. They checked the logs and it showed a ton of alerts. They did also check and that at times the car has an unexplained power draw on the 12V of approx 3A. I did ask them to put in a new 12V battery, they said would if it's defective.

If the 3A draw is real then even a new 12V battery may not have worked anyway. It's always best to determine the root cause before just changing parts regardless of who pays for the replacement parts.
 
Agreed that something else is going on and that just replacing the 12V is not likely to solve the issue. I find it amazing Tesla service has access to a bunch of stats. I wished that the data was available to us as well.

Would be nice but giving us easy access would probably just be another headache for Tesla. I'm reminded of that instance where the guy kept checking sentry mode while his car was in the shop and getting frustrated when the shop wasn't actively working on the car.
 

jjrandorin

Moderator, Model 3, Tesla Energy Forums
Moderator
Nov 28, 2018
14,577
18,637
Riverside Co. CA
Agreed that something else is going on and that just replacing the 12V is not likely to solve the issue. I find it amazing Tesla service has access to a bunch of stats. I wished that the data was available to us as well.

I actually dont agree with "the new 12v is not likely to fix this". The sequence of events described says to me that aftermarket screen was providing a drain in your battery, and contributed to (but did not fully cause) your 12v battery to fail. The second "Im stuck" issue is actually the exact same as the first, because you didnt change anything. You put the original 12v (that was likely failed) back in the car.

Since you took the screen out, if you dont put it back in, I am betting you would have no issue. I am also betting that even if you put the screen back in, but put in a new battery, you wont have an issue (at first).

From your statement, the logs show a drain, so the battery is getting drained (and will be charged by the main HV battery) more than normal, likely leading to an "earlier" battery 12v issue, but not leading to instant death of the battery.

Either dont use the screen at all, and plan on replacing the battery every 3 ish years, or use the screen and plan on replacing it proactively at 2 years.

Thats my opinion, anyway.
 
I actually dont agree with "the new 12v is not likely to fix this". The sequence of events described says to me that aftermarket screen was providing a drain in your battery, and contributed to (but did not fully cause) your 12v battery to fail. The second "Im stuck" issue is actually the exact same as the first, because you didnt change anything. You put the original 12v (that was likely failed) back in the car.

Since you took the screen out, if you dont put it back in, I am betting you would have no issue. I am also betting that even if you put the screen back in, but put in a new battery, you wont have an issue (at first).

From your statement, the logs show a drain, so the battery is getting drained (and will be charged by the main HV battery) more than normal, likely leading to an "earlier" battery 12v issue, but not leading to instant death of the battery.

Either dont use the screen at all, and plan on replacing the battery every 3 ish years, or use the screen and plan on replacing it proactively at 2 years.

Thats my opinion, anyway.
I'm not clear on the timing of the removal of screen and the note about a 3A draw.

I read that is that the car logged a 3A draw was dated AFTER the removal of the screen. If that's the case you need to find the source (i.e short) or it will kill the new 12V battery the same as the old one.

If the car was drawing 3A PRIOR to removal of the screen I'd go with the issue possibly being the screen.
 
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I'm not clear on the timing of the removal of screen and the note about a 3A draw.

I read that is that the car logged a 3A draw was dated AFTER the removal of the screen. If that's the case you need to find the source (i.e short) or it will kill the new 12V battery the same as the old one.

If the car was drawing 3A PRIOR to removal of the screen I'd go with the issue possibly being the screen.
Is the 3A draw while the car is sleeping? If so, that is high. Last time I measured my cars asleep current it was about 500-600 ma.
 
Just came to this post, because I've had a similar experience with my 2018 Model 3 RWD LR. My 12V died, when my PTC heater failed. The heater has been on/off failing since January, and have been waiting for the part, but on a Friday a couple weeks ago, the car said that it 'may not restart; schedule service'. Sure enough, then next day, car wouldn't go into gear, and a lot of messages came up about the electrical system shutting down. Tesla confirmed that it was due to the PTC heater faulting and affecting the high voltage loop. Couldn't drive it to Tesla, so arranged for a tow on the Monday. On the weekend, went to get the tow hook installed and empty the car and nothing. Couldn't open doors/connect to the car with app/key card not working/etc... Went and got a 12V 51R battery from Cdn Tire and got the frunk popped, installed the battery and was able to set it up for the tow. By the next morning, the new battery was completely dead. Towed to Tesla, they fixed the PTC heater after a week & a half (I guess you get priority if your car is dead in their lot), and I got a message that it was ready to pick up. Asked if the Cdn Tire battery was OK and they said it looked fine. Next morning, went to pick my car up and there's a 'Schedule service to replace low voltage battery' message. I went into the service, and they said to take the battery back to Cdn Tire under warranty and get it replaced :rolleyes: I asked if they could replace the battery, and they were too busy. Apparently, they would rather me service the battery. Anyhow, I was looking on here, to see if I maybe trickle charge this 12V battery, that's practically brand new, if it would come "back to life", or if I'm better off removing and replacing this battery (because apparently I'm a Tesla repair person now). Very disappointed in Tesla service. Having to live with sporadic heat since January in Canada, and then have the car become inoperable due to them not having the part, me having to replace battery and get a $400 tow (the service station is almost an hour away from me), and picking up a car that needs service still,... ugh.
 

jjrandorin

Moderator, Model 3, Tesla Energy Forums
Moderator
Nov 28, 2018
14,577
18,637
Riverside Co. CA
or if I'm better off removing and replacing this battery (because apparently I'm a Tesla repair person now). Very disappointed in Tesla service.

You made yourself one in this instance when you replaced the 12V yourself, unfortunately. They should have just replaced it for you and charged you for replacing it. I wasnt there, but they likely didnt replace it because they were not going to replace an aftermarket battery under warranty for any reason, and there was an aftermarket one in there so they knew you either did it or had means to do it.
 

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