How to Tell When Your Tesla’s 12v is About to Die (before you're stranded)

Every Tesla has a 12v battery under the hood, also known as the low voltage system (versus the high voltage powertrain battery). The Tesla's 12v battery replacement can be quite the process, so it's best to look out for the warning signs of a failing Model 3 12v battery or Model Y 12v battery (also applies to S/X), before it leaves you stranded.

12v battery specs: The battery is a group 51R, but it turns out Tesla uses a very certain type of this battery with an unknown EV-rating. You may be able to install a generic 51R battery in your Tesla, but buying & replacing directly from Tesla seems to be the best and only proper option.

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🙋‍♂️ I'm Troy, an EV & Tesla Enthusiast, Cybertruck pre-order holder, and Model Y SR owner. My role is to document, hype up, and explore electric cars, large and small, with refined visuals.

I go on Tesla road trips often with my Standard Range Model Y, and document it all! For behind-the-scenes and casual updates, check out my Twitter, The Cybertruck Guy, or my Instagram, @TroyMeekhof.

0:00 Explanation
0:59 Signs of Battery Failure
3:38 How the Battery Fails
4:47 Battery Replacement Options

[donsolo]

Mine died with no warning (no messages, no errors, no sign of it failing). Very annoying. Then again, only issue I have had with my MY in the three years I have owned it.

[ptech]

My 2018 just notified me of an issue with the 12 v battery. No issues setup appointment on the app along with a brake cleaning had it done 2 days later for a grand total of $275. No fuss no muss. Love tesla

[moestrei]

My 12V battery died during an overnight software update. I live 450km (inland Australia) from the next service center. The software update was incomplete and the car not chargeable or drivable. Luckily i knew how to open the frunk and luckily (again) my ride-on mower battery fitted in ok. Tesla Service then shot through a new update ota and all was good. Car was not happy about the foreign battery but i dove for a few weeks until i needed to go to the coast and getting the right battery then.

[treborg]

I’ve just changed the 12V battery in my 2017 MX for the second time preemptively because the consequences of letting the battery die are so serious. I change the big HEPA filter (“bioweapon” filter) at the same time, since it has to come out to access the battery. Changing the battery every three years is a good guideline.

[TeslaPrince]

FYI, i've seen a dozen videos claiming you can pop the frunk with a 9v or those small 12v batteries but not always! I helped a friend on his model y and tried both but they did not work, his 12v was REALLY dead due to his heat pump sezing and the high voltage battery would no longer charge his 12v. To open the frunk i had to use a lithium ion booster pack with the 'boost' feature turned on. Same to open the doors. So beware, those smaller 9v and 12v solutions may still leave you stranded, always have access to a booster pack.

[julienvm]

FYI, newer Teslas are equipped with li-ion batteries operating at 15-16V, rather than traditional lead operating at 12V

[dathyr]

Awesome. Thanks for all this information. I knew about the 12 volt battery, but had no idea how long they last. I live in Northern Illinois, so we also get cold winters.
Thanks for all the possible warning signs. I got my Tesla August 2023 and hopefully good for a while with my 12V battery.
Thanks and take care.

[mikesevgarage]

Great video Troy! I’m hoping that I get a long life out of mine because it’s the lithium one 🤞

[charliemeyer]

My 12 volt died in less than 3 years with no warning. Totally inconvenient but it was replaced for free under warranty. The service tech came out and was finished in less than 10 min.

[jimadams]

My first 12 volt battery only lasted 27 months. I'm replacing it every 2 years now.

[kevinfletcher]

You make it sound as though this is an EV problem. All cars have a 12 battery. My ICE car is 7 years old. Battery still going strong.

[phat_gunpla_etc]

of course if you worried you can replace the 12v battery early right?

[lenimbery]

There’s also a place in the service menu with the voltages and health displayed. I’m guessing that if there’s a problem the error notices might pop up at the same time as anything shows here though

[Scott-smnm]

5:35 I'm pretty sure that I read a 9v battery will allow you to open your hood? UPDATE: the 12v looks like a better option as I've seen mix results on the 9v. Alternative way to keep the 12v is here: YT Tesla Model 3/Y - Hide An Emergency Battery - Tesla Tips by MTN Ranger

[cajunmike]

My car was dead this morning and it never showed me a warning. Of course, my car is a lil over 3 years old. Service wants to bring it in to check the whole car out.

[sidnickels]

Interesting insight about the distribution deal they would have had with Suge Knight, Irv Gotta, Puff Daddy, Dame, and Jay Prince!

[roadbiker]

Does Tesla service perform 12v battery replacement

[SteveMuncy-zydk]

A few important points that need to be emphasized. Since 2022 the lithium 16 volt battery has replaced the 12v battery and the lifespan of these batteries is 8-10 years and may be covered under the standard warranty. I believe that 12v will still pop the frunk in systems with the 16v battery. The system is designed to not allow popping the frunk from the accessible wires unless the battery is really dead thus preventing frunk access by thieves.

[HLF]

5:30 seen it been opened with a standard 9V battery also when the car was completely bricked… It even got the doors to unlock and to restart the computer…🤔

[HubertHeller]

Mine went dead without any warning whatsoever after 2 and 1/2 years. Tesla sent a tow truck and towed the car to the service center. It's the only issue I had with my model Y. The Tesla technician said that there must have been a sudden drop of voltage, that's why there was no advance warning.