Had a 12 volt battery failure the other day. Had my M3 for less than 2 years. Fortunately I was at home and I needed to pull vehicle back in the garage. Got into the car and closed the door. No power at all. Had to use the door lever to open door. Contacted Tesla and they could not communicate with vehicle. They setup a tow to the service center. Battery was replaced quickly but did not think about the driver window after using lever. Drove the car home and did not immediately realize the window was down about 1/2 inch. The window would bounce down when rolled up. Setup a mobile service appointment. The window just needed a recalibration. Tesla does warn about using the lever and this is what could happen. Wanted to share this for others.
Master thread: Model 3 12v Battery issues, monitoring, Aftermarket replacement
- Thread starter mikesyl27
- Start date
-
- Tags
- 12 volt 12 volt battery
moderator note: making this thread to consolidate the 12 volt battery failure discussion into a single thread going forward. I am not planning on moving historical threads into this one, as that would render it *unreadable.
Moving forward, experiences and discussion regarding the 12v Battery in the model 3 (failure, replacement, aftermarket options, etc) should occur here so people can find them in one place.
Some historical threads, so people can find previous discussions on the topic (which helped me decide to make a master thread on the topic).
Replace 12 volt battery
12 volt battery "back-up?"
Looking for a replacement 12 volt battery
Can a Tesla jump an ICE vehicle with 12 v battery? [Update: Tesla says NO]
How and when does the 12v battery get charged?
Vehicle shutting down please pull over safely [edit: 12v battery issue]
12v battery horror story
Replace 12 volt battery
Planning to replace 12V in M3 with Lithium Ohmmu battery.
What's with the Ohmmu 12V battery?
How does Ohmmu Battery perform in Hot Climate
Ohmmu Battery & 2020.28.6 update
*side note: In case people are curious on my statement on "not merging previous threads as it would make this one unreadable", I explained what happens in the following thread, the link below goes to the specific post. This is only for those who might be curious as to why I am not merging those threads above into this one.
Vehicle shutting down please pull over safely [edit: 12v battery issue]
Moving forward, experiences and discussion regarding the 12v Battery in the model 3 (failure, replacement, aftermarket options, etc) should occur here so people can find them in one place.
Some historical threads, so people can find previous discussions on the topic (which helped me decide to make a master thread on the topic).
Replace 12 volt battery
12 volt battery "back-up?"
Looking for a replacement 12 volt battery
Can a Tesla jump an ICE vehicle with 12 v battery? [Update: Tesla says NO]
How and when does the 12v battery get charged?
Vehicle shutting down please pull over safely [edit: 12v battery issue]
12v battery horror story
Replace 12 volt battery
Planning to replace 12V in M3 with Lithium Ohmmu battery.
What's with the Ohmmu 12V battery?
How does Ohmmu Battery perform in Hot Climate
Ohmmu Battery & 2020.28.6 update
*side note: In case people are curious on my statement on "not merging previous threads as it would make this one unreadable", I explained what happens in the following thread, the link below goes to the specific post. This is only for those who might be curious as to why I am not merging those threads above into this one.
Vehicle shutting down please pull over safely [edit: 12v battery issue]
Last edited:
Thanks to our moderator JJ.
If you are having a 12v problem or had one, it would be nice to track some basic info to see if there are any patterns to the premature failures.
vin - just the last 6 figs
Date of mfr on your door sill
Mileage
Any warnings, what were they?
If you had a warning, how long before failure?
Any other electrical oddities before failure?
Generally, how many hrs a day is your 3 unplugged?
Garaged, or outdoors?
State of residence to get an idea of the ambient temps.
Do you run Sentry?
Overheat protection?
Smart summon?
Anything else that might draw power while you’re not in the car? 3rd party dashcam? Radar?
Do you know your average phantom drain rate, miles/hr?
If you’ve looked at your 12v battery, what brand is it and date of mfr?
If you are having a 12v problem or had one, it would be nice to track some basic info to see if there are any patterns to the premature failures.
vin - just the last 6 figs
Date of mfr on your door sill
Mileage
Any warnings, what were they?
If you had a warning, how long before failure?
Any other electrical oddities before failure?
Generally, how many hrs a day is your 3 unplugged?
Garaged, or outdoors?
State of residence to get an idea of the ambient temps.
Do you run Sentry?
Overheat protection?
Smart summon?
Anything else that might draw power while you’re not in the car? 3rd party dashcam? Radar?
Do you know your average phantom drain rate, miles/hr?
If you’ve looked at your 12v battery, what brand is it and date of mfr?
Last edited:
Tz00
3 LR AWD
And check the 12V battery with a volt meter to see what voltage it has when it is "dead". Is it low or open-celled at 0V.
cruiserlarry
Gadgetologist
My 2019 M3 got the "12V battery requires service" warning after it refused to boot up for about 10 minutes. Once I rebooted the car, everything fired up OK, but the warning continued, and a software update kept aborting (along with a "Driver window open" alert even though it's not open). I put a tester on the 12V battery, and it showed 14.2V and 92% capacity while connected to the car. I figured maybe the Voltage Controller was giving it a false high reading because it was still charging it - so I bought a replacement battery from Tesla, and installed it. No change, even after reboot - the "12V service required soon" warning stayed, as well as the window open alert. Put a tester on the new installed battery - 14.2V and 100% capacity. Tested the removed battery, and out of the car it shows 13.3v and 92% capacity; definitely not a bad battery, although the sides were a bit puffed out as if it had been overcharged...
Other than rebooting, is there something to reset after replacing the battery to eliminate the warning ?
Other than rebooting, is there something to reset after replacing the battery to eliminate the warning ?
Tz00
3 LR AWD
You have to fully power cycle the car (disconnect 12V battery, open contactor under back seat), to get rid of that warning, (or it may go away on its own eventually).
Here are detailed instructions: Tesla Model 3 Hard Reset | Mountain Pass Performance
Did you choose to self replace the battery instead of calling for service because you are out of warranty or something?
cruiserlarry
Gadgetologist
No - I choose to do it because Tesla didn't have an appointment available for 2 weeks, and I need to be able to make sure the vehicle was safe to drive, and would not cause my wife to be stranded. Very frustrated that I wasn't offered a mobile service appt, or any way to request it. I emailed 3 service centers, left voicemails for previous techs I've worked with, and responded to the text messaging appt confirmation, but no luck so far. I am a licensed auto tech, own a company that custom builds vehicles, and have 45 years auto mechanical / electrical / design/ fabrication experience (including many hybrids, etc) so I didn't think it would be difficult (changing the battery took less than 10 minutes, actually, including watching YouTube videos for confirmation). I did research first for any special conditions, and found many videos, etc, showing no additional steps required, including from Ohmmu batteries (which is different than the Model S and X procedure, which I've also done successfully). I tested the existing battery (which actually checked out fine electrically, but had bulged suggesting overcharging might be occurring), and tested the brand new Tesla battery, which was OK, prior to installing it. The vehicle is driving fine, but the warning remains despite the battery being good.
I'll do the suggested hard reset to see if that eliminates the issue, or if not, it might be a voltage controller problem - I'll have Tesla check the system since I kept my appt.
cruiserlarry
Gadgetologist
Thanks for taking the time to respond. Thats super unfortunate that they couldnt take care of it for you before that time. I also find it interesting that someone in your field, with your experience has a model 3 as a vehicle, when its likely you could have (or build) just about anything you wanted to.
cruiserlarry
Gadgetologist
I also have a Model S, and a couple of custom off-road focused expedition vehicles....but I love new tech, everything automotive, and being an early adopter - and it only took one drive in a Tesla to know I wanted one (my first was a 2015 Model S, now a 2017 Model S and 2019 Model 3 and we have 2 Model Ys and another Model S in my immediate family). Aside from my off-road / business related vehicles, I'll never by an ICE car again. I'm just hoping the Cybertruck and Rivian make it to production soon, so I can replace my ICE trucks as well, and convert my expedition vehicles to EVs...
judyjetson
Member
Too expensive. I'd buy the Tesla one. If it was an emergency I'd buy a cheaper 51R.
judyjetson
Member
Yes, certainly expensive. But, if it lasts longer and is worth the payoff...Just was curious if anyone else has installed one.
With the 12V battery obviously being a critical component of the car, I'll probably replace it every 2 years, as preventative maintenance. Being a 51R, it's not that expensive, and MUCH better than getting stranded in the middle of nowhere at 100F+ (or freezing), and with no cell service, no? Ha ha. Anyway, can anybody tell us the brand and exact model of the battery on these cars? Is it an AGM?
My immediate question is WHY they're failing. If it's a good battery (like from Johnson Controls, now Clarios), I'd eliminate a defect as the reason, being so many cars, and so soon. Since the car supposedly maintains the battery charged, it's sounding like it's an OVERCHARGING issue, rather than undercharging, no? But I'd like to know which one it is. A yellow Optima would be a lot better battery if the issue is undercharging, since yellow Optimas are deep-cycle batteries. But if the issue is overcharging, they'd be worse IMO. So we need to know what the suspected problem is before choosing what to replace it with.
My immediate question is WHY they're failing. If it's a good battery (like from Johnson Controls, now Clarios), I'd eliminate a defect as the reason, being so many cars, and so soon. Since the car supposedly maintains the battery charged, it's sounding like it's an OVERCHARGING issue, rather than undercharging, no? But I'd like to know which one it is. A yellow Optima would be a lot better battery if the issue is undercharging, since yellow Optimas are deep-cycle batteries. But if the issue is overcharging, they'd be worse IMO. So we need to know what the suspected problem is before choosing what to replace it with.
AlanSubie4Life
Efficiency Obsessed Member
This has been discussed in similar threads - Master thread: Model 3 12v Battery issues, monitoring, Aftermarket replacement. You can purchase the battery for $85 from Tesla (or $124/$129 installed I think). It's the only source I am aware of - currently a "perfect" equivalent (which would be cheaper or the same price) is not stocked at auto parts stores.
Based on the price and battery manufacturer documents (see other threads), probably it is not AGM (do not confuse with other Tesla models which may well be AGM according to TeslaTap, etc.). If it's not AGM, it's probably best to not replace the battery with an AGM battery as the charging profiles are slightly different, from what I understand. Also it's cheaper to get the Tesla battery. AGM would probably work fine but no idea really.
How long do you usually have once you get the 12v battery has aged or degraded message before the car will have a problem? Got appt booked but ok to keep driving for how long?
Yes.
The "benefits" of these expensive 12volts are mostly just marketing claims that haven't been proven in the real world. Specifically the claims about being cheaper in the long run since nobody has had them long enough yet.
I looked into it a couple years ago emailed Ohmmu's predecessor (renamed) and a salesman in every negative connotation of the word assured me it would be fine here near Green Bay where my Tesla has experienced -20f and I have seen it colder. Didn't reference any BMS or temp controls, said it was close enough to the main pack it would get that cold.
My S got over 4 years out of the first battery and more than 2 sofar on the second, 102k miles.
Similar threads
