12 volt battery dies without warning

[clivetaylor]

My 2021 Tesla model 3 12 volt battery just died without any warning. A few months ago my nieghbor had the exact same issue with his 2021 Y.
When this happens it’s like a stroke one half of the car is paralyzed and only the passenger side door will unlock. You are unable to remove the charger plug and your will be totally stranded . The battery is under warranty but the bug question for me , a little heads up your battery is dying. Neither of us received any warning and luckily my nieghbor and I had this happen at home and not on the road.
Now I have to wait till Friday for service and since this happened I can’t get in the car at all and I have items I need to retrieve from the car and I can’t get in. Very frustrating.

 

[one2many]

Yep

 

[one2many]

ICE car is no different I guess, batteries go.

 

[rpiotro]

Yes, they often do that. Maybe why the switch to Lithium-Ion batteries.

Are you in a very warm climate? That can significantly shorten Lead-acid battery life. Otherwise they are generally good for four to five years. I replace mine at five years as a preemptive move.

There is a procedure where you can "jump" the car to at least get the doors open. The answer lies behind the front tow hook cover. RTFM.

 

[Flybyglass]

My 2021 Tesla model 3 12 volt battery just died without any warning. A few months ago my nieghbor had the exact same issue with his 2021 Y.
When this happens it’s like a stroke one half of the car is paralyzed and only the passenger side door will unlock. You are unable to remove the charger plug and your will be totally stranded . The battery is under warranty but the bug question for me , a little heads up your battery is dying. Neither of us received any warning and luckily my nieghbor and I had this happen at home and not on the road.
Now I have to wait till Friday for service and since this happened I can’t get in the car at all and I have items I need to retrieve from the car and I can’t get in. Very frustrating.

There is a procedure to open the frunk. You can access it:

Model Y Do It Yourself | Tesla

It's in the support section of the tesla web site under DIY/ model Y/LV battery. That will give you access to the 12 volt battery. There is also DIY to replace it. The Tesla battery is inexpensive or at Advance Auto you could get a DiehardEV battery that is AGM. (the factory battery contrary to some misinformation is a flooded lead acid). The factory battery has high cranking amps at 45. The owners manual just says anything 33ah or greater in the specifications works. The standard battery size is 51R. Road side assist can help you gain access to the car. If you can wait, the factory battery will be warranty. Otherwise there its a DIY guide in the same section for replacement.

 

[Gasaraki]

I don't know why people are surprised that 12V batteries die suddenly. Every ICE car has been like that. I never had my car tell me that the 12V was about to die.

 

[Flybyglass]

I don't know why people are surprised that 12V batteries die suddenly. Every ICE car has been like that. I never had my car tell me that the 12V was about to die.

Tesla has adjusted the software to advise if the 12 volt battery is failing but it may not be reliable.

 

[clivetaylor]

Yes, they often do that. Maybe why the switch to Lithium-Ion batteries.

Are you in a very warm climate? That can significantly shorten Lead-acid battery life. Otherwise they are generally good for four to five years. I replace mine at five years as a preemptive move.

There is a procedure where you can "jump" the car to at least get the doors open. The answer lies behind the front tow hook cover. RTFM.

Only two years old as well as Nieghbor’s it’s uncanny they both went I suspect faulty battery but most annoying I got an alert after the battery died saying it may be going

 

[Pham]

ICE car is no different I guess, batteries go.

Except ICE cars don't lock you out if it's battery dies though lol. OP can't even get back into the car to grab some items he needs.

 

[charlieaf92]

I don't know why people are surprised that 12V batteries die suddenly. Every ICE car has been like that. I never had my car tell me that the 12V was about to die.

I think it's more of the fact that when it does die, you can't open the doors or do anything with the car. If it happens in an ICE car there is a straight forward procedure to unlock doors, open the hood, etc. Not to mention you can jump start the car to avoid having it towed for something as common and virtually guaranteed as a 12v battery going bad. In the Tesla it becomes a crippling failure, which seems like a massive design oversight.

There is a warning that is supposed to start giving you a heads up - but it didn't work for me either. This was the night before we were showing our house for sale and my car was stuck in the driveway. Rather than wait 3 days for a mobile tech to come out and replace it, I pulled the battery myself and drove it to the service center. Despite being told in the app that bringing the battery in for a swap would be fine, I got there and was forced to pay for the replacement (only $90 which is reasonable, but it was under warranty). They said at the SC that they would only do a warranty swap if they replaced it themselves. Kind of annoyed because that's not what the documented chat log shows, but I had already driven 30 minutes and had the battery there.

 

[Gasaraki]

There is no reliable way to tell if the 12V battery is about to fail unless the battery has sensors and logic in it. A standard 12V is a dumb battery and they can try to tell by voltage but that's not reliable at all. So no, I don't think there's a vehicle out there ICE or EV that uses the regular 12V battery that can preemptively tell you that the 12V is going to fail. Just Tesla even trying to put some logic on the software is already more than every other car out there.

I'm assuming the new Teslas with the Lithium batteries has actual battery management in them and can tell when it is about to fail.

 

[android04]

Tesla does not only measure voltage but also tracks current going in and out of the 12v battery. That gives them a lot of info, but they don't have a fool-proof way of detecting a battery failure before it happens 100% of the time. To better measure the health of the battery, it has to be disconnected from the circuit and that's not possible while it's in use (which is all the time). Tesla periodically tweaks the software that charges, discharges, and monitors the battery with the goal of making it better. However, it will never be 100%.

The good news is that it's fairly easy to pop open the frunk and jump start or replace the 12v battery. Also, the 12v battery is not special and you can buy a replacement at any auto parts store and many hardware and big box stores. The battery is an a Group Size 51R and is not AGM, though most of the batteries you can find that have the vent hose connection like the OEM battery are AGM.

 

[804son]

Definitely a problem w/ ICE vehicles as well. My Jeep Wrangler battery died at 2 years. Wouldn't accept a jumpt and I had to have it towed. I could get in the vehicle, but I was still stranded at work. Just to add insult to injury.

 

[fholbert]

Instead of waiting 5 days for a warranty replacement, just buy a battery at the local auto supply and be done with it.

ICE cars do give some warning, the starter slows down.

 

[Rice&Curry]

Instead of waiting 5 days for a warranty replacement, just buy a battery at the local auto supply and be done with it.

ICE cars do give some warning, the starter slows down.

It is not a regular 12V battery which you can buy in any Auto shop, so please find out the details of the 12V battery which will fit your Tesla vehicle before you buy the 12v battery.

 

[RedModel3]

When mine was about to die, there were multiple little things that started going wrong - easy to miss. I just got lucky that wasn't stuck.

 

[rpiotro]

Instead of waiting 5 days for a warranty replacement, just buy a battery at the local auto supply and be done with it.

ICE cars do give some warning, the starter slows down.

Rarely before a sudden death.

 

[Msjulie]

I proactively changed mine right about 4 years; had ICE car batteries go longer and shorter and didn't want the hassle

 

[father_of_6]

It is not a regular 12V battery which you can buy in any Auto shop, so please find out the details of the 12V battery which will fit your Tesla vehicle before you buy the 12v battery.

You sure about that? As far as I can find, it's a "Group Size 51R", and they seem to be available at Napa, AutoZone, Walmart, and everywhere else.

It's true that ICE cars experience this too and without warning... but it's also true that when it happens in your ICE car it's easier to resolve. In a Tesla you're locked out and can't easily pop the frunk to replace it.

The solution, as others have mentioned, is to open the tow hook panel on the front of the car and short circuit the wires using a small 12v or 9v battery to pop the frunk. Then you can replace your 12v battery using basic tools as you would with your ICE vehicles (socket set).

Read the manual for more accurate and specific details regarding popping the front with a dead 12v.

 

[Casmium]

Except ICE cars don't lock you out if it's battery dies though lol. OP can't even get back into the car to grab some items he needs.

you should read up on the fiskar karma, for good measure it would lock you in if the battery died