Welcome to Tesla Motors Club
Discuss Tesla's Model S, Model 3, Model X, Model Y, Cybertruck, Roadster and More.
Register

Model 3 12v battery dead

JTesmod3

Member
Jul 20, 2018
252
287
Los angeles
Just wondering if I could gather stories of what happened with owners and what happened so that we could gain insight with this issue, I've been looking around the internet but wanted to condense stories here...

Personally had a warning the day before, I scheduled the service for 5 days from then (earliest available) the next day the car was completely dead, when I opened the door the windows started rolling down very slowly but the cars screen did not work, even the button to open the door was unresponsive. The car was completely inoperable to the point they could not even put it in neutral to move to tow the car. A quick internet search showed that it was probably the 12 volt battery which Tesla confirmed and replaced under warranty.

I want to know if this should worry me...I've taken road trips with this car and in some cases these places were isolated, what worries me is that this might happen again and I want to be able to see it before it does. In my case I had a warning the day before then the next day the car was completely inoperable.
 

smatthew

Active Member
Jun 9, 2018
1,293
2,241
CA Bay Area
There are many threads on here. Perhaps you could view or search before pasting? If you had, you would have known to just call the service number, report your car as inoperative, and there would have been a tow-truck there in an hour or two, with the battery replaced shortly after it arrived at the service center.
 

JTesmod3

Member
Jul 20, 2018
252
287
Los angeles
There are many threads on here. Perhaps you could view or search before pasting? If you had, you would have known to just call the service number, report your car as inoperative, and there would have been a tow-truck there in an hour or two, with the battery replaced shortly after it arrived at the service center.

This is after the fact...I actually went on the app and scheduled the pickup (faster than calling)...if I would've came on here I would've seen your advice and been on the phone for a hour ;)
 

JTesmod3

Member
Jul 20, 2018
252
287
Los angeles
Every car, not just Tesla, is at risk of sudden failure of the 12V battery. Nothing unique about Tesla in this regard.

LOVE TESLA but it shakes me a little when I use the car for 1000+ mile road trips knowing that I could be stuck literally in death valley without any kind of major warning, I was hoping to use this post so people can say what to look out for/warning signs
 

JPP

Active Member
Feb 4, 2013
3,078
1,326
SF Bay Area, CA
Data point--

A week ago I had a Ranger out for a 2 year check on my 2018 P3D+ with about 12889 miles. The car was fine--no issues. Ranger checked the fluids (brake fluid and coolant), torqued the lug nuts, topped off the windshield washer fluid, changed my wiper blades. All good. $85. No complaints over 2 years.

The next day I get a firmware update to 2020.36. Installs fine. I do the usual reboot. All good.

I did not drive the car after the firmware update.

Fast forward to just a couple of days ago. I go into my garage to head out--and there is the characteristic rotten egg sulfur smell. I walk up to the driver's door and I can open the cat. But car just won't boot. I try the '2 thumb salute'--won't boot. I call Tesla Roadside to report the issue--they (like me) assume the 12V is bad. They call for a flatbed. While I wait (about 45 minutes) I open the access port on the front bumper and using a 12V supply I pop the frunk. I pull the access cover over the battery and meter the 12V battery--6V.

The car was towed to Tesla Dublin, where they replaced the 12V battery under warranty. No reported issues with charging or DC-to-DC.

Kind of odd so close to a firmware update, and I assumed that the battery died from overcharging. Guess time will tell...
 
Last edited:

Fernand

Active Member
Mar 22, 2019
1,619
1,791
Northern california
There's got to be some way to hot wire or jump the car, like every kid knows to do.

What if you jumped the 12 V from another car or a standalone battery? It couldn't need much amperage to start the computers, and then it should feed off the main battery, no?

It's a needless and unacceptable anxiety-provoking item. You can't drive out into Deliverance banjo country, 'cause nobody knows how to hot wire one of them newfangled rich folks' electric cars, so you'll be stuck for days waiting for somebody to come rescue you?? With no Starbucks lattes!

Before long the TSLA shorts and Detroit will start making up stories about families shriveling up out there, in spite of parts stores and 12v batteries in plain sight, LOL

If this is prevented by some interlock, then dear Tesla MAKE IT POSSIBLE, come on, now, ASAP!

Or do you plan on charging us steeply for coming out to do it, after the 4 years' warranty expires?
.
 
Last edited:

HelixSpiral

Member
Oct 19, 2018
96
120
Cincinnati
There's got to be some way to hot wire or jump the car, like every kid knows to do.

What if you jumped the 12 V from another car or a standalone battery? It couldn't need much amperage to start the computers, and then it should feed off the main battery, no? If this is prevented by some interlock, then dear Tesla MAKE IT POSSIBLE, now, ASAP!
.
You can use another car to jump the 12v battery.

You cannot, however, use the 12v battery to jump start another car.
 
  • Like
Reactions: smatthew

Fernand

Active Member
Mar 22, 2019
1,619
1,791
Northern california
Jump start another sucker loser's car? Surely you jest.

No, but seriously, is that all it takes, a jump, and you can be off and rolling to e.g. the nearest Service Center?
.
 

JPP

Active Member
Feb 4, 2013
3,078
1,326
SF Bay Area, CA
Jump start another sucker loser's car? Surely you jest.

No, but seriously, is that all it takes, a jump, and you can be off and rolling to e.g. the nearest Service Center?
.

FWIW when the flatbed came to tow me, yes, they did jumper the 12V to get the car to boot up to allow it to be driven onto the flatbed. But it would be really iffy to assume that the 12v electrical system would be happy with a bad 12v (like my 6V) and a 2nd 12v hooked up to it. I would assume that the charging system and electrical system might not tolerate this. And if you suddenly lose the 12V, AFAIK you are dead in the water (...or on the highway).
 
  • Disagree
Reactions: smatthew

bpjones

Member
Nov 16, 2018
102
127
Houston, TX
Data point--

A week ago I had a Ranger out for a 2 year check on my 2018 P3D+ with about 12889 miles. The car was fine--no issues. Ranger checked the fluids (brake fluid and coolant), torqued the lug nuts, topped off the windshield washer fluid, changed my wiper blades. All good. $85. No complaints over 2 years.

The next day I get a firmware update to 2020.36. Installs fine. I do the usual reboot. All good.

I did not drive the car after the firmware update.

Fast forward to just a couple of days ago. I go into my garage to head out--and there is the characteristic rotten egg sulfur smell. I walk up to the driver's door and I can open the cat. But car just won't boot. I try the '2 thumb salute'--won't boot. I call Tesla Roadside to report the issue--they (like me) assume the 12V is bad. They call for a flatbed. While I wait (about 45 minutes) I open the access port on the front bumper and using a 12V supply I pop the frunk. I pull the access cover over the battery and meter the 12V battery--6V.

The car was towed to Tesla Dublin, where they replaced the 12V battery under warranty. No reported issues with charging or DC-to-DC.

Kind of odd so close to a firmware update, and I assumed that the battery died from overcharging. Guess time will tell...

All 12V batteries have a finite life. They work great until suddenly they fail. Occurs the same way in ICE cars.
 

JTesmod3

Member
Jul 20, 2018
252
287
Los angeles
Don’t you have the same risk of being stranded due to a flat tire?

I suppose your right; it's just I think a flat tire is easier to take than a total failure of the car with little warning. To me it seems like a flat tire is something that can happen but a model 3 that's completely unresponsive feels like something that shouldn't happen
 

danarcha

Member
Feb 9, 2020
96
134
South Bend, IN
I suppose your right; it's just I think a flat tire is easier to take than a total failure of the car with little warning. To me it seems like a flat tire is something that can happen but a model 3 that's completely unresponsive feels like something that shouldn't happen

I suppose if you are that concerned, (and I'm not criticizing you for that concern, as a new M3 owner I share your concerns after reading these threads) you could order an Ohmmu replacement battery, or equivalent, and put it in your trunk for a long trip. It seems silly that owners of the most advanced electric cars on the planet might need to carry around a spare 12V battery, but I guess that's our current situation.
 
  • Like
Reactions: Mrcarcrazy

Fernand

Active Member
Mar 22, 2019
1,619
1,791
Northern california
... let's not forget to take a spare tire, since the gooey inflator that Tesla sells allegedly doesn't work on these foam-filled Michelins. Let's see, what else ... ?
 
Last edited:

android04

Member
Apr 1, 2016
515
526
Southeast Nebraska
... let's not forget to take a spare tire, since the gooey inflator that Tesla sells allegedly doesn't work on these foam-filled Michelins. Let's see, what else ... ?
And a gas-powered generator in case you run out of charge. And a satellite phone in case you get in an accident and there's no cell phone signal. And some self-healing rescue tape to seal off the coolant lines in case you run over a log or dead animal and it breaks the coolant lines under the car at the back of the wheel wells.

I think a little knowledge is better. And people are making a bigger deal about the 12v battery than there needs to be.
 

smatthew

Active Member
Jun 9, 2018
1,293
2,241
CA Bay Area
A sudden failure at 2 years seems a bit premature, and FWIW I live in a temperate climate, so no freezing temps.
Yeah, but you have a 2018 car. Model 3's consumed higher amounts of power while "asleep" in the early days, leading to additional charge cycles being put on the 12V batteries, leading to their early demise. That was resolved late 2019.
 
  • Like
Reactions: M109Rider

JPP

Active Member
Feb 4, 2013
3,078
1,326
SF Bay Area, CA
Yeah, but you have a 2018 car. Model 3's consumed higher amounts of power while "asleep" in the early days, leading to additional charge cycles being put on the 12V batteries, leading to their early demise. That was resolved late 2019.

Agree, but FWIW my wife's 2015 S70D gave the obligatory '12V battery needs service' warning, and I had time to conveniently have it replaced. In the case of my 2018 P3D+, the battery was fine with no warning messages, and then cooked and at 6V the next day. Precipitous failure, not gradual degradation.
 

Products we're discussing on TMC...

About Us

Formed in 2006, Tesla Motors Club (TMC) was the first independent online Tesla community. Today it remains the largest and most dynamic community of Tesla enthusiasts. Learn more.

Do you value your experience at TMC? Consider becoming a Supporting Member of Tesla Motors Club. As a thank you for your contribution, you'll get nearly no ads in the Community and Groups sections. Additional perks are available depending on the level of contribution. Please visit the Account Upgrades page for more details.


SUPPORT TMC
Top