Tesla’s Battery Day detailed a variety of topics that are related to the future of cell manufacturing efficiency. However, the presentation also showed how the automaker is improving the design of its vehicles by utilizing a new battery architecture. Tesla plans to adopt the same strategy within its vehicles to improve mass, range, and the structural integrity of its vehicles.
Teslarati reported earlier this year that Tesla would be using a single-piece casting design on the Model Y. The improved casting eliminates 79 parts per car, which not only increases manufacturing efficiency but also increases safety for drivers. The cost of each vehicle’s rear underbody design also decreases by 40% thanks to the casting, which is performed by a massive machine known as the Giga Press.
The single-piece rear casting is made from Tesla’s own high-pressure aluminum alloy that has a high strength thanks to no heat treatment or coatings that would take away from the structural integrity of the design. Heat treating a casting of this size after manufacturing causes deformation, CEO Elon Musk said during the event.
However, the manufacturing team at Tesla also drew inspiration from aircraft wings to improve the structural integrity of its vehicles. While the casting improves manufacturing efficiency and strength, the positioning of structural batteries eliminates excess structure from the battery packs, increasing density.
“The non-cell portion of the battery has negative mass,” Musk said. “We saved more mass in the rest of the vehicle than in the non-cell portion of the battery. So how do you really minimize the mass of the battery? Make it negative.”
The minimization of negative mass allowed the automaker to increase the density of the battery pack. Individual cells could be positioned more efficiently because excessive structures within the pack itself were eradicated. The new Tesla battery design is completely free of any negative mass, which improves pack density along with structural integrity.
“The pack itself is structural,” Musk stated.
Additionally, the filler within the Model 3 and Model Y packs, which currently uses a flame retardant, now uses a structural adhesive and flame retardant. This adhesive effectively attaches the cells to the top and bottom sheets of the pack. “This allows you to do sheer transfer between the upper and lower sheet,” which increases stiffness and prevents major deformation in the event of a crash.
Improvements in the casting design of Tesla’s future cars and the newly designed battery architecture, which uses new materials and strategies to increase stiffness, will increase the already safe vehicles that the company manufactures. Tesla already holds three separate five-star crash safety ratings with the Model S, Model 3, and Model X. The Model Y has not yet been tested, but the vehicle does use the one-piece rear casting design already at the Fremont production facility.
Tesla’s Battery Day did not disappoint. While the blueprint to cell manufacturing efficiency was laid out, the company also showed how battery layout and architecture could increase Tesla’s vehicle safety. The new design revolutionizes EVs as a whole and will eventually lead to more safety than previously displayed.
Elon Musk
Tesla gives the Roadster an official “Go for launch” demonstration date
Tesla teased an October 1 Roadster reveal, reviving years of delayed SpaceX thruster hover promises.
Tesla teased an October 1 event date for its next generation Roadster, posting an image on X Saturday that shows the car lit up like it is sitting on a launch pad, with the date “10.01” stamped across the bottom and the caption “Go for launch.” A countdown clock on Tesla’s Roadster order page now points to the same date, which falls on a Thursday. The company has not said where the event will happen or whether it will be streamed at the moment. Stay with us @Teslarati for live updates.
Go for launch pic.twitter.com/Khu03eiZ04
— Tesla (@Tesla) September 12, 2026
Tesla has since sent formal invitations to reservation holders confirming the event will take place in Waco, Texas, about 90 minutes north of its Austin headquarters, based on a digital ticket shared on X by Sawyer Merritt. Tesla did not name the exact venue, though Waco sits close to SpaceX’s McGregor, Texas, rocket test site, previously reported as the planned location for a Roadster thruster demonstration. The invite sets the reveal for 8:30 p.m. Eastern on October 1, requires RSVPs by midnight on September 16, and limits entry to guests 21 and older. Invitations are non-transferable.
The tease follows nine years of a project defined by unimaginable specs along with slipped dates. Musk first showed the second generation Roadster in November 2017 as a surprise reveal at the end of the Tesla Semi event, promising a 0 to 60 mph time under two seconds, a top speed above 250 mph, 620 miles of range from a 200 kWh battery, and production starting in 2020. At last November’s shareholder meeting, Musk set an April 1 demo date and joked the choice gave him “deniability” if it slipped again, which it did, moving first to late April, then to “a month or so,” then to August.
Tesla Roadster SpaceX Package’s 1.1-second 0-60 mph launch visualized in concept video
Whatever Tesla shows on October 1 is expected to center on the SpaceX developed thruster package Musk has described since 2018. Internally code named A71, a nod to the Lockheed SR-71 Blackbird, the system reportedly uses cold gas thrusters fed by a composite overwrapped pressure vessel, the same tank design SpaceX uses on Falcon 9. Musk has said a thruster equipped Roadster could hit 60 mph in about 1.1 seconds under roughly 2.75 g of launch force, well past the 1.9 second figure quoted for the standard car. That version reportedly will not be street legal and has reportedly been discussed as a limited run sold through a track only program.
The standard Roadster is still expected to carry the original $200,000 base price and $250,000 Founders Series tier, both set when Tesla opened $50,000 and $250,000 reservations in 2017. Tesla VP of Vehicle Engineering Lars Moravy has confirmed production will happen at Gigafactory Texas, with Musk targeting 2027 or 2028, 12 to 18 months after whatever the company demonstrates next month.
Tesla is planning to roll out some pretty significant safety and accident avoidance features with Full Self-Driving version 15, which will be the next major FSD deployment from the company.
Tesla AI lead Ashok Elluswamy used a near-miss this week to preview what the company says is the next leap in Full Self-Driving.
In response to a driver whose car had swerved away from another vehicle pulling out of a parking lot, Elluswamy wrote that he was glad the owner was safe and that “even earlier prediction of hazards, even faster reaction time and overall significantly better safety and collision avoidance” would arrive with FSD v15.
Glad you are safe. Even earlier prediction of hazards, even faster reaction time and overall significantly better safety and collision avoidance coming as part of the next big upgrade (v15).
— Ashok Elluswamy (@aelluswamy) September 11, 2026
The comment landed as Tesla continues to treat software as the primary safety upgrade path. v15 is described internally as a larger architectural step, with a much bigger neural network and tighter coupling between prediction and control.
The company has already begun using early v15 software in some robotaxi operations while rolling out safety features such as Automatic Collision Evasion into current customer cars, allowing the driving stack to intervene even when the driver is in manual control.
Tesla is rolling out a new FSD version with a massive safety addition
Tesla’s published telemetry is the backbone of its safety argument. In recent North American Vehicle Safety Report data, vehicles with FSD (Supervised) engaged traveled roughly 5.1 million to 5.7 million miles between major collisions, defined as airbag-deployment events.
Tesla’s estimate of the U.S. average over the same period is about 699,000 miles per comparable crash. That is the comparison Tesla often frames as roughly seven times fewer major collisions.
A tighter comparison uses the same Tesla fleet. Cars driven manually with active safety features such as automatic emergency braking still recorded a major collision about every 2.1 million miles. Against that baseline, FSD’s advantage shrinks to roughly 2.4 to 2.7 times fewer severe crashes, which independent researchers argue is the more apples-to-apples figure.
European data released in 2026 pointed in the same direction: Tesla reported FSD as 3.5 times safer than manual driving in the Netherlands and 4.1 times fewer collisions than manually driven Teslas with active safety across more than 100 million kilometers in five approved countries.
Those numbers do not settle every debate. NHTSA’s Standing General Order still shows Tesla accounting for the large majority of U.S. Level 2 driver-assist crash reports, in part because the fleet logs far more assisted miles than rivals. Critics also note that Tesla’s “U.S. average” mixes crash definitions and driving mix.
Even so, Tesla’s own same-car comparisons, plus lower rates of automatic emergency braking and harsh maneuvers when FSD is engaged, are the evidence Elluswamy is pointing to when he says v15 will push prediction and collision avoidance further. The claim is not that software already eliminates risk. It is that each major version is meant to widen the gap between the system and an unaided human driver.
Cybertruck
Tesla’s most delayed Cybertruck feature is finally here
Tesla finally links Cybertruck Powershare with Powerwall 3 for extended home backup after years overdue.
Tesla’s Cybertruck can now pair with a Powerwall 3 to keep a house running longer during an outage, a feature the company first promised when the truck launched in November 2023.
The official Cybertruck account posted the update on X Thursday: “Powerwall 3 & I can now power your house together. This extends your home backup by over 3 days, equivalent to 9 additional Powerwalls,” Cybertruck lead engineer Wes Morrill confirmed the rollout separately, calling it the first time a vehicle and a home battery have worked together this way. Powerwall 2 and Powerwall+ compatibility is still coming later this year, per both the Cybertruck account and Morrill.
Powerwall 3 & I can now power your house together⁰ ⁰This extends your home backup by over 3 days, equivalent to 9 additional Powerwalls pic.twitter.com/8G2twIm6AN
— Cybertruck (@cybertruck) September 10, 2026
Powershare itself is not new. Tesla enabled the version that lets Cybertruck power tools, appliances or another EV through its bed outlets when the truck launched in 2023. Home backup through a Powershare Gateway and Universal Wall Connector arrived in 2024, and Tesla extended that support to homes with solar the following year. What has been missing until now is Powershare working alongside an existing Powerwall, instead of functioning as a separate backup source competing for the same job.
The pairing matters because a single Powerwall home battery typically covers a home for about a day, less if usage is heavy or the outage stretches into a heat wave or freeze. A second Powerwall for more backup storage costs several thousand dollars installed. A Cybertruck instead uses a battery the owner already has, one large enough here to add roughly three more days of backup without mounting another unit or booking an installer visit. For households in wildfire, hurricane or winter storm regions where outages run past a day, that keeps the refrigerator and medical equipment running instead of shutting down.
The company told owners in October 2024 that Powerwall integration was coming sometime in 2025. That date passed, and in December 2025 Tesla pushed the target to mid-2026, with Morrill explaining at the time that two grid-forming devices need to negotiate which one manages a home during an outage, and that certifying the process across multiple generations of Powerwall took longer than expected.
For owners who bought Powershare hardware expecting it to work with whatever battery setup they already had, Thursday’s update closes a gap that has shown up repeatedly in owner complaints since Cybertruck deliveries began. Tesla has also rolled out a separate Powershare grid support program in Texas, letting Cybertrucks send power back to the grid during high demand events, so the truck’s role in a home’s energy setup keeps expanding even as individual pieces of it arrive later than promised.
Tesla gives the Roadster an official “Go for launch” demonstration date
Tesla plans big safety improvements for Full Self-Driving v15
