Lifestyle
Understanding the Tesla 12V Battery Service Warning
During the time when I was sitting on the sideline waiting patiently for delivery of my Model S, I read up on pretty much anything and everything related to the vehicle. I remember reading about 12V battery failures on the Model S, something Elon himself even commented on during one of the earnings calls.
RELATED: Tesla Model S 12V Lithium-Ion battery replacement (up to 70% lighter, 4x life)
It was reported that Tesla had chosen a poor vendor for the 12V battery which impacted early Model S owners but apparently this issue is still happening across later production vehicles. My Model S as well as several others that I personally know of received the 12V battery service indicator. For me this took place after 7 months and 18,000 miles of ownership.
Purpose of the Tesla 12V battery
Tesla Model S 12V Battery (source: TMC forum)
The 12V battery in the Model S performs many of the same duties as it would in any internal combustion engine (ICE) car.The connections to the 12V battery on a Model S appear to be a bit more complex than in a traditional ICE as seen in the following picture (source: TMC forum).
RELATED: Why Tesla’s lead acid 12V battery needs to be lithium-ion based
The 12V battery maintains power for critical systems when the main battery pack is damaged or disabled. It powers the hazard lights, airbags, door locking and unlocking operations, as well as other critical componets of the Model S. The 12V battery also ensures that electronics are “awake” and listening to the key FOB in order to automatically lock and unlock the vehicle based on proximity. It also allows the car to maintain its 3G connection for remote access when the rest of the vehicle is powered off. If the 12V battery happens to fail, it will isolate the main battery pack from the car and prevent charging. This is a safety feature of the Model S designed to help protect first responders in the event of an accident.
What does my warning mean?
The “12V Battery Needs Service” warning can indicate a number of problems and the only way to truly understand the reason for the alert is to call Tesla Service (they’re available 24×7) and have them pull the logs. This is something that Tesla service can diagnose remotely.
Tesla 12V battery terminal
In severe cases Tesla Service will tell you to stop driving the car, but generally it’s an indication that the voltage level has dropped below a certain threshold but the vehicle can continue to operate normally until replaced. In the rare event that the the 12V battery dies while driving, the car will become disabled and will require a jump start to power on again. Our friend Kman has a good video on getting access to the terminals behind the nosecone to jump start the 12V, but please consult Tesla service and take caution before attempting this on your own.
Depending on the severity of the issue, there may be a 2-3 week lead time before Tesla Service replaces the 12V battery.
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Many owners manage to get the battery replaced quickly, but in my case a busy Tesla Service Center combined with the fact that it was Thanksgiving holiday during a snowy New England week, had me driving with the warning light on for almost 2 weeks (about 1,000 miles) without encountering any issues.
Another interesting point to note is that Tesla may call you before you even see 12V battery service warning. Multiple owners have reported this proactive stance in advance of a warning which is great to see. Evidently Tesla’s early warning threshold is supersedes the trigger that kicks off the dash indicator.
Why are the 12V batteries failing?
Some owners are on their 3rd 12V battery already. Many others are reporting failures at the 1 year mark. In ICE cars you can normally expect about 4 years of life before needing to replace the 12V battery which begs the question – why are Tesla 12V batteries failing?
Some of the failures have been in the DC to DC converter that charges the 12V battery through the main battery pack. That converter can be seen as an equivalent to the alternator in your traditional ICE car. However, this doesn’t seem to be the main cause of the 12V battery failures. Current conjecture is that vampire load and the excessive strain on the 12V are causing the reliability issues.
Tesla may have a lingering design issue in their use of the 12V battery.
From my reading, I think they upgraded the quality of the battery in the earlier models but we’re still facing the same underlying design issue in the way the 12V is stressed. Can Tesla fix the way the 12V battery is used with software updates alone? We don’t know, but fortunately they’re taking care of all of the replacements in the meantime. Unless they can address it remotely via software updates, there could be a factory “recall” brewing (and I use this term loosely).
Either way, Tesla should be more upfront about these issues and let owners know what they’re doing to address the underlying problem.
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Getting the 12V battery serviced
From everthing I’ve heard and experienced through my own Model S, the replacement including labor and parts is 100% covered by Tesla.
Tesla Service can handle the replacement at your location, but given the poor weather conditions here in New England, I opted to have them pick up my Model S and do the replacement in the comfort of their own Service Center. They were able to service it within the same day, and to Tesla fashion they also updated/fixed a bunch of other minor things for free, while at it.
Summary
The 12V battery is a relatively inexpensive part in the Model S and is fairly simple to replace, but the bigger concern is why they seem to be failing so quickly. It isn’t a major issue for now but certianly something we should continue monitoring as concerned Model S owners.
I’ve started a poll over on TMC to see what kind of failure rate we’re seeing on the 12V battery so feel free to contribute to it or use it as a way monitor progress. So far over 75% of respondents have had their 12V battery replaced within 2 years.
Firmware
Tesla unlocks in-car web conferencing to extend Google Meet, Teams and beyond
Tesla’s Summer Update lets owners join Google Meet, Teams, and Discord calls via cabin camera.
Tesla’s 2026 Summer Update, which just began rolling out to customer vehicles, now links the built-in web browser with the in-cabin camera feed and microphone input, thereby letting owners join video calls on nearly any browser-based service instead of just Zoom.
The change appears in Tesla’s own release notes for software version 2026.26 under “Web Browser,” which states that the vehicle can now use its interior camera and cabin microphone when a website requests access, with permission granted the same way a desktop browser handles it. As NotATeslaApp notes, this feature opens the door to Google Meet, Microsoft Teams, Discord, and other webcam-enabled sites to activate the in-car cabin-facing camera. The feed automatically crops and zooms to center the driver in frame.
Tesla has offered in-car video calling before, but only through a dedicated Zoom app that launched at the end of 2022, a stripped-down browser preloaded with Zoom’s own web client and gated behind Premium Connectivity. Opening the full browser to any camera-requesting site removes that walled garden. Elon Musk first called video conferencing “definitely a future feature” back in 2020, when the pandemic pushed remote meetings into daily life, so this update effectively finishes something Tesla has been promising for six years.
Tesla Summer Update begins rolling out: a look at the new features
The feature keeps the same restrictions that applied to Zoom on Tesla vehicles. It only works while the car is parked; shifting into Drive disables the camera feed, according to the release notes. It is also limited to vehicles running Tesla’s AMD Ryzen infotainment hardware, meaning older Intel-based Model S and Model X units, along with early Model 3 and Model Y builds, don’t get it.
Turning the browser into a general entry point for the in-cabin camera, rather than routing everything through one local app, widens the number of third-party sites that can ask for access, even though Tesla’s permission prompt.
With the Summer update only days into its rollout, be sure to stay with us on TikTok and X to see the latest video demonstrations.
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Elon Musk escalated his monthslong feud with Christopher Nolan’s The Odyssey this week, pledging that his own AI video tool will produce a competing version before the year is out. Responding to a fan-made, AI-generated clip of the ancient epic, Musk wrote on X, “Before this year ends, Grok Imagine will make a full-length movie of The Odyssey that is historically accurate and true to the art of Homer.”
In June, Musk quoted an xAI-shared trailer built entirely with Grok Imagine Video 1.5, a two-minute-plus reimagining of The Odyssey styled after a 1970s classical Hollywood epic, and predicted “full movies by the end of the year,” as Teslarati reported at the time. That trailer, built from 36 consistent shots by a single creator, was Musk’s proof of concept. This week’s pledge turns that prediction into a specific commitment, tied directly to Homer’s text rather than a generic demo.
Before this year ends, Grok Imagine will make a full-length movie of The Odyssey that is historically accurate and true to the art of Homer https://t.co/bVHzUmY9WN
— Elon Musk (@elonmusk) July 22, 2026
When a fan separately proposed that Musk fund a live-action alternative, to “give Mel Gibson $100 million to film an Odyssey adaptation with painstakingly historically accurate ships, armour, weapons, and casting, with all dialogue taken straight from the original poem and delivered in Homeric Greek,” Musk replied with two words: “I’m down.”
The Grok Imagine pledge lands as the tool’s underlying infrastructure has changed hands. Grok is no longer a standalone product, it folded into SpaceXAI after SpaceX’s acquisition of xAI closed in February, meaning the compute behind any Odyssey production traces back to the same Colossus supercomputers now bundled into SpaceX’s pitch to investors. Musk has separately said SpaceX’s own engineering data is being fed into the next major Grok training run, a two trillion parameter model he’s called the “2T run.”
Whether Grok Imagine can sustain a feature length narrative, rather than a series of impressive individual shots, remains the open question.
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Cybertruck
Tesla Mobile App gets a new feature that wrap fans are going to love
Tesla’s Summer Update removes the USB drive step from customizing your car’s digital wrap design.
Tesla’s latest 2026 Summer Update quietly closes out one of the more tedious steps in personalizing a Tesla’s digital appearance. Uploading a custom wrap design used to require a USB drive. Now it doesn’t.
The feature is listed in Tesla’s release notes as “Send Custom Wraps from Mobile App.” The company described it plainly: “Skip the USB drive and upload a custom wrap of your car from the mobile app. Instructions for creating a custom wrap here: github.com/teslamotors/custom-wraps.”
The digital wrap tool has been around since Tesla’s 2024 Holiday Update, when it launched for Cybertruck owners first, as Teslarati reported at the time. Getting a design onto the car meant formatting a USB drive, creating a folder named exactly “Wraps,” dropping in PNG files sized between 512×512 and 1024×1024 pixels and under 1 MB each, then plugging the drive in and applying the wrap through Toybox. Tesla expanded the tool to other models and renamed it from “Colorizer” to “Paint Shop” with the 2025 Holiday Update, while also adding license plate and window tint customization alongside the wraps.
Custom wraps via mobile app https://t.co/5OydZ26g9p pic.twitter.com/uexU0ZePxu
— Tesla (@Tesla) July 22, 2026
The latest Summer Update removes the USB step from that process. Owners will be able to pull a design from wherever they saved it, whether that’s a download from social media or something built from Tesla’s own GitHub templates, and push it to the car directly through the app.
Tesla reveals 2026 Summer Update with crazy fixes to Nav and more
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It’s a small fix relative to the rest of this latest release, which also included expanded Grok voice commands, automatic navigation that learns regular routes, and self-driving stats inside the mobile app, all detailed in our rundown of the full Summer Update. The USB requirement was one of the more common complaints about Paint Shop since it launched. Tesla did not say when the wrap upload change would reach individual vehicles, only that the broader update is rolling out now in waves.
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