News
Tesla ‘Roadrunner’ cell leak hints that Battery Day will be more insane than expected
Tesla’s Battery Day has been hyped so much that the event will have to include something truly amazing to live up to its expectations. In the lead up to the highly-anticipated event, a leaked image featuring what is supposedly a cell from Tesla’s “Roadrunner” line has emerged. And if the leak proves legitimate, it would appear that Battery Day will not only meet expectations — it will be even more insane than expected.
The leaked image, which was initially published in a report on Electrek, featured a massive battery cell that was supposedly a product of the Roadrunner line. The publication noted that the image was sent through an anonymous source and confirmed by another independent source. From the get-go, it is evident that the cell is massive, closer in size to a supercapacitor than a traditional battery cell. Initial observations by battery enthusiasts online also point to some radical improvements that such a cell design would bring.
While Electrek’s sources have mentioned that the Roadrunner cell will feature roughly double the diameter of the 2170 cells that the electric car maker currently uses in the Model 3 and Model Y, Tesla enthusiast @_BRCooper, who is familiar with battery tech, has observed that one of the leaked images had the number “054” printed on its side. If this number represents the cell’s diameter, it would point to Tesla’s Roadrunner cells adopting a 54×98 form factor, which has 10x the volume of a 2170 cell.
As noted by Jordan Giesige of The Limiting Factor channel on YouTube, adopting a 54×98 form factor for its next-generation cells has numerous implications for the entire battery manufacturing process and the performance of Tesla’s vehicles as a whole. With the larger cells, Tesla could produce battery packs that have an order of magnitude fewer cells than before. This would result in the company only using 1/10 the number of rolls, cans, electrolyte fills, and welds compared to its current operations. Such a strategy opens the doors to massive cost reductions that could help bring down the prices of electric cars to a notable degree.
But regardless of its actual size, the design of the Roadrunner cell appears to be optimized and designed for a cell-to-pack drop-in setup. Interestingly enough, the leaked image of the Roadrunner cell seems to have a tabless electrode design, which Elon Musk has dubbed is “way more important than it sounds” last year. Provided that the Roadrunner cells are indeed inspired by Tesla’s tabless electrode patent, the new form factor could pave the way to more performance and further reductions in production costs.
What’s even more notable is that these improvements become possible with just the Roadrunner cell’s new form factor and design. Giesige, for his part, has noted that with the Roadrunner cell’s design and potential 54×98 form factor alone, Tesla may be able to close in on 300 wh/kg before making any significant changes to its battery chemistry. Elon Musk actually mentioned a 30-40% improvement from 250 wh/kg back in 2018, which translates to an improvement to 325-350 wh/kg. Musk’s prediction was considered fantastical by critics then, but as Battery Day approaches and leaks start to emerge about the event, it is starting to look more and more likely that 325-350 wh/kg is feasible.
Watch a feature on the Roadrunner battery cell leak in the video below.
Yesterday, we reported on Tesla Cybertruck getting some major adjustments from a manufacturing standpoint in an effort to make the all-electric pickup more cost-effective, more reliable, more serviceable, and more easily produced.
Tesla Cybertruck engineer reveals new changes in ‘constantly evolving’ pickup
One of those changes was the addition of a self-reinforcing polypropylene aero shield that sits underneath the truck. Previously, Tesla utilized aluminum for this, but the self-reinforcing polypropylene was more durable while also being cheaper and lighter.
Tesla has revealed another small change it made to the Cybertruck, and it has to do with the side repeater cameras.
Tesla does not wait for a new model year to improve its vehicles. On September 8, Cybertruck lead engineer Wes Morrill posted side-by-side photos of an updated side repeater camera housing now rolling off the line at Gigafactory Texas.
The triangular camera pod mounted on the front fender looks almost identical at first glance. A closer look reveals a revised contour that uses the air already flowing around the truck to keep the lens clearer in rain and road spray.
The side repeater camera was updated – the version on the left is the newer part which uses passive geometry to create airflow disturbance that better keep water off the lens while driving. No cost penalty, just pure vision improvement. pic.twitter.com/wAbXtcL1Jf
— Wes (@wmorrill3) September 8, 2026
The side repeater cameras sit in an exposed position on the Cybertruck’s angular stainless-steel body.
In wet weather, they readily collect water droplets that can degrade the image Autopilot and Full Self-Driving use for lane changes and blind-spot monitoring. Early production trucks sometimes left owners wiping lenses by hand or accepting temporary restrictions on driver-assistance features.
Tesla has added washers to cameras on certain other models and on Cybercab prototypes, but those active systems add cost, complexity, and extra potential leak points.
The new housing solves the problem with passive geometry. Subtle changes in the surround create localized airflow disturbances as the vehicle moves. Those eddies physically push water droplets away from the optical surface. Morrill called the result “pure vision improvement” achieved at “no cost penalty.” Once the production mold is updated, every subsequent part costs the same as the original.
The advantages compound quickly. Clearer cameras in rain improve the reliability of driver-assistance features precisely when they are needed most. The design consumes no extra energy and introduces no new failure modes.
New Cybertrucks built after the tooling changeover receive the updated part automatically. Some owners of trucks delivered as late as June 2026 have already confirmed they received the revised housing. Retrofit questions have appeared in replies, and the cameras appear electrically compatible, though Tesla has not announced an official service program.
A few millimeters of reshaped housing will not make headlines the way a new battery pack does, but these changes are incremental and increase the Cybertruck’s effectiveness as a vehicle over time.
This improvement illustrates how Tesla continues to refine the Cybertruck after volume production began. Better wet-weather vision, zero added cost, and no extra hardware add up to a meaningful gain in everyday usability and safety.
Tesla is rolling out a new version of its Full Self-Driving suite to some owners that comes with the massive addition of a safety feature.
Tesla is rolling out Automatic Collision Evasion with the 2026.27.6 Software Update, which started rolling out to some vehicles last night. We received the update, along with Full Self-Driving v14.3.9, as well as v14.2 Lite, which has identical release notes as the previous version and seems to have some refinements and improvements in behavior and performance.
🚨 Tesla FSD v14.3.9 is rolling out as well as 2026.27.6 which includes Automatic Collision Evasion
Brand new safety features from a software update. My Tesla gets better everytime I get one of these pic.twitter.com/ctrMiQXWhM
— TESLARATI (@Teslarati) September 8, 2026
However, most of the attention has fallen on the Automatic Collision Evasion feature, which we covered in an article last week.
The function will activate Full Self-Driving to “try to keep your vehicle safe and then continue driving. It can engage in the following situations while you are driving manually:
- Scenario 1: A frontal collision is imminent and braking alone may not avoid it.
- Scenario 2: Your vehicle detects that you are not sufficiently attentive to the road (for example, reaching toward the back seat), or that Full Self-Driving (Supervised) may have been unintentionally disengaged.”
Essentially, FSD will take over when the vehicle determines you are not paying sufficient attention or are heading toward a potential collision. The addition of this feature is incredibly useful as distracted driving is a major issue in today’s world.
Along with the new safety feature is Tesla FSD v14.3.9, which has no additional release notes compared to the previous version, but in my first drives, my first impression is that operation is great, and parking is still sort of a pain point.
Just took a 15-mile round trip to the gym and back
Pretty on par with what FSD is nowadays – really good. Not enough time to see what’s good and what’s bad, but these first rides on any version feel shockingly good. They’re all pretty identical https://t.co/WN1qTg4bhE
— TESLARATI (@Teslarati) September 9, 2026
Additionally, Tesla v14.2. Lite has arrived. A great review of that is available here:
— Zack (@BLKMDL3) September 9, 2026
The addition of an Automatic Collision Evasion feature is similar to that of other collision avoidance systems that are used by companies like Hyundai, Kia, and Genesis. These programs typically utilize radar and camera sensors to apply emergency brakes autonomously, though evasive steering in a manual driving mode is pioneered primarily by Tesla’s newest addition.
Elon Musk
Tesla primes Cybercabs for 4K streaming and high bandwidth gaming with Starlink integration
Tesla is now shipping Cybercabs from Giga Texas with Starlink hardware built in as standard.
Tesla’s Cybercabs are now leaving Gigafactory Texas with Starlink hardware on the rear hatch in significant numbers, according to drone footage captured Tuesday by longtime Austin drone observer Joe Tegtmeyer. Production at the factory ramped back up after the Labor Day weekend, and his flyover of the outbound lot showed rows of gold Cybercabs alongside Model Y Long Wheelbase units, many carrying the satellite module for the first time as standard equipment rather than a one off retrofit.
Giga Texas today is busy with production coming back up following the long weekend. Of interest today in the outbound lot is the appearance of hundreds of Mode; YL’s and many more Cybercabs and for the 1st time equipped with the Starlink module one the hatch in big numbers.
At… pic.twitter.com/G9yl6s51m4
— Joe Tegtmeyer 🚀 🤠🛸😎 (@JoeTegtmeyer) September 8, 2026
Tesla first showed Starlink built into an actual Cybercab on August 10, when the Robotaxi account posted images of a single gold unit with the antenna integrated into the roofline above the taillights and called it the first Cybercab with Starlink integration. That followed a July reveal where Tesla and Starlink jointly posted a cutaway diagram of the antenna placement without a working vehicle to back it up. Ashok Elluswamy, Tesla’s VP of AI software, said at the time that the connection isn’t required for the car to drive itself. It exists mainly for navigation, customer service and keeping tabs on the fleet.
Musk has made a different case in public. During Tesla’s Q2 earnings call, he said the company can’t afford robotaxis stranded in what he called “Bermuda Triangles of lack of cellular connectivity,” and he separately claimed on X that Starlink will eventually reach every Tesla built, calling it the only way to deliver high bandwidth to billions of vehicles. He has also pitched the antenna as an entertainment upgrade, telling riders they would be able to stream 4K video or play games during a trip.
The rollout has moved fast since. Robotaxi service opened to the public in Austin on September 3, and Cybercabs had already been spotted with Starlink hardware in Houston and near Miami International Airport in the weeks before Tuesday’s factory footage showed the module shipping at volume rather than on scattered test units. Whether the satellite link earns its keep is still an open question. Tesla’s unsupervised service currently runs in dense metro geofences in Texas and Florida, markets where cellular coverage is already strong, which is not where the rural dead zones Musk describes tend to show up.
This tiny Tesla Cybertruck adjustment has big advantages
Tesla is rolling out a new FSD version with a massive safety addition
