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.
News
Tesla Model Y and Model 3 named safest vehicles tested by ANCAP in 2025
According to ANCAP in a press release, the Tesla Model Y achieved the highest overall weighted score of any vehicle assessed in 2025.
The Tesla Model Y recorded the highest overall safety score of any vehicle tested by ANCAP in 2025. The Tesla Model 3 also delivered strong results, reinforcing the automaker’s safety leadership in Australia and New Zealand.
According to ANCAP in a press release, the Tesla Model Y achieved the highest overall weighted score of any vehicle assessed in 2025. ANCAP’s 2025 tests evaluated vehicles across four key pillars: Adult Occupant Protection, Child Occupant Protection, Vulnerable Road User Protection, and Safety Assist technologies.
The Model Y posted consistently strong results in all four categories, distinguishing itself through a system-based safety approach that combines structural crash protection with advanced driver-assistance features such as autonomous emergency braking, lane support, and driver monitoring.
This marked the second time the Model Y has topped ANCAP’s annual safety rankings. The Model Y’s previous version was also ANCAP’s top performer in 2022.
The Tesla Model 3 also delivered a strong performance in ANCAP’s 2025 tests, contributing to Tesla’s broader safety presence across segments. Similar to the Model Y, the Model 3 also earned impressive scores across the ANCAP’s four pillars. This made the vehicle the top performer in the Medium Car category.
ANCAP Chief Executive Officer Carla Hoorweg stated that the results highlight a growing industry shift toward integrated safety design, with improvements in technologies such as autonomous emergency braking and lane support translating into meaningful real-world protection.
“ANCAP’s testing continues to reinforce a clear message: the safest vehicles are those designed with safety as a system, not a checklist. The top performers this year delivered consistent results across physical crash protection, crash avoidance and vulnerable road user safety, rather than relying on strength in a single area.
“We are also seeing increasing alignment between ANCAP’s test requirements and the safety technologies that genuinely matter on Australian and New Zealand roads. Improvements in autonomous emergency braking, lane support, and driver monitoring systems are translating into more robust protection,” Hoorweg said.
News
Tesla Sweden uses Megapack battery to bypass unions’ Supercharger blockade
Just before Christmas, Tesla went live with a new charging station in Arlandastad, outside Stockholm, by powering it with a Tesla Megapack battery.
Tesla Sweden has successfully launched a new Supercharger station despite an ongoing blockade by Swedish unions, using on-site Megapack batteries instead of traditional grid connections. The workaround has allowed the Supercharger to operate without direct access to Sweden’s electricity network, which has been effectively frozen by labor action.
Tesla has experienced notable challenges connecting its new charging stations to Sweden’s power grid due to industrial action led by Seko, a major Swedish trade union, which has blocked all new electrical connections for new Superchargers. On paper, this made the opening of new Supercharger sites almost impossible.
Despite the blockade, Tesla has continued to bring stations online. In Malmö and Södertälje, new Supercharger locations opened after grid operators E.ON and Telge Nät activated the sites. The operators later stated that the connections had been made in error.
More recently, however, Tesla adopted a different strategy altogether. Just before Christmas, Tesla went live with a new charging station in Arlandastad, outside Stockholm, by powering it with a Tesla Megapack battery, as noted in a Dagens Arbete (DA) report.
Because the Supercharger station does not rely on a permanent grid connection, Tesla was able to bypass the blocked application process, as noted by Swedish car journalist and YouTuber Peter Esse. He noted that the Arlandastad Supercharger is likely dependent on nearby companies to recharge the batteries, likely through private arrangements.
Eight new charging stalls have been launched in the Arlandastad site so far, which is a fraction of the originally planned 40 chargers for the location. Still, the fact that Tesla Sweden was able to work around the unions’ efforts once more is impressive, especially since Superchargers are used even by non-Tesla EVs.
Esse noted that Tesla’s Megapack workaround is not as easily replicated in other locations. Arlandastad is unique because neighboring operators already have access to grid power, making it possible for Tesla to source electricity indirectly. Still, Esse noted that the unions’ blockades have not affected sales as much.
“Many want Tesla to lose sales due to the union blockades. But you have to remember that sales are falling from 2024, when Tesla sold a record number of cars in Sweden. That year, the unions also had blockades against Tesla. So for Tesla as a charging operator, it is devastating. But for Tesla as a car company, it does not matter in terms of sales volumes. People charge their cars where there is an opportunity, usually at home,” Esse noted.
Elon Musk
Elon Musk’s X goes down as users report major outage Friday morning
Error messages and stalled loading screens quickly spread across the service, while outage trackers recorded a sharp spike in user reports.
Elon Musk’s X experienced an outage Friday morning, leaving large numbers of users unable to access the social media platform.
Error messages and stalled loading screens quickly spread across the service, while outage trackers recorded a sharp spike in user reports.
Downdetector reports
Users attempting to open X were met with messages such as “Something went wrong. Try reloading,” often followed by an endless spinning icon that prevented access, according to a report from Variety. Downdetector data showed that reports of problems surged rapidly throughout the morning.
As of 10:52 a.m. ET, more than 100,000 users had reported issues with X. The data indicated that 56% of complaints were tied to the mobile app, while 33% were related to the website and roughly 10% cited server connection problems. The disruption appeared to begin around 10:10 a.m. ET, briefly eased around 10:35 a.m., and then returned minutes later.
Previous disruptions
Friday’s outage was not an isolated incident. X has experienced multiple high-profile service interruptions over the past two years. In November, tens of thousands of users reported widespread errors, including “Internal server error / Error code 500” messages. Cloudflare-related error messages were also reported.
In March 2025, the platform endured several brief outages spanning roughly 45 minutes, with more than 21,000 reports in the U.S. and 10,800 in the U.K., according to Downdetector. Earlier disruptions included an outage in August 2024 and impairments to key platform features in July 2023.
Tesla Model Y and Model 3 named safest vehicles tested by ANCAP in 2025
Tesla Sweden uses Megapack battery to bypass unions’ Supercharger blockade
