Tesla’s Battery Day is coming tomorrow after the electric car maker’s 2020 Annual Shareholder Meeting. During the event, Tesla is expected to discuss the details of its next-generation battery cells, as well as their role in the world’s acceleration in sustainable energy. Actual details about Battery Day have been pretty scarce save for a few potential leaks, but that has not stopped the Tesla community from speculating about what the highly-anticipated event would involve.
A concise summary of the current expectations for Battery Day was recently shared by Tesla Daily’s Rob Maurer, who compiled a list of topics that the electric car maker could cover during the event. Following then is a list of expectations about what Tesla could discuss tomorrow, as the company finally shows the world what it has been working on with regards to its battery technology.
A New Cell Design
Tesla has been teasing that it would be going into the production of battery cells. So far, leaks suggest that the company is about to adopt a larger form factor for its batteries, similar to how Tesla introduced the 2170 cells for the Model 3, which were larger than the 18650 cells used in the Model S and Model X. Leaks have pointed to Tesla’s new cells possibly adopting a 54×98 form factor, which has about 10x the volume of a 2170 cell.
With larger form factors, the electrons and the ions travel larger distances as they move around in the cell, generating more friction and heat. This is a huge downside to larger cells, but Tesla’s tabless battery patent may hold the key to solving this issue. With a tabless battery cell design, the distance traveled by electrons and ions is largely reduced, limiting the disadvantages inherent among large cells. Such a design has several advantages, including better energy density and a more efficient manufacturing process.
Battery Chemistry
Speculations are abounding that Tesla may discuss the amount of silicon that it is using in the anode of its next-generation cells. The more silicon that is used, the better the energy density. However, the utilization of silicon usually results in cracked anodes over time, reducing battery performance and life. Introducing more silicon into the anode is something that battery researchers have been attempting to accomplish for a while now, so it would be quite interesting if the electric car maker would announce some headway into its silicon use as well.
Tesla may also discuss Maxwell’s technology and how it is being used for the company’s electric cars and energy storage devices. Maxwell has developed numerous innovations prior to its acquisition by Tesla, though the most relevant part of the company’s work in relation to the electric car maker is arguably its dry battery electrode tech. Considering that traditional lithium-ion batteries produce their electrodes in a wet slurry format (a rather lengthy process), dry electrode technology could vastly improve not only the energy density of Tesla’s cells, they could improve the production output of the batteries themselves as well.
Cell-to-Pack Innovations
Tesla’s battery packs today feature cells that are packed into modules that are then packed into a battery pack. Back in the days of the original Roadster, battery modules were used as a means for the company to take out parts of the battery that may need to be replaced without taking out the entire pack. That was 12 years ago, however, and much has happened since then. Tesla has transitioned from a budding niche electric car maker to the manufacturer of the market’s best-selling EVs.
As Elon Musk noted in the past, battery modules today are pretty much just an extra step, taking up weight without really serving a legitimate purpose. Musk then stated that the future is cell to pack without modules, suggesting that the company’s next-generation batteries will be using a cell-to-pack design. Such an innovation gives numerous benefits to Tesla, from lower production costs to possibly even better energy density.
Battery Manufacturing and the Roadrunner Line
Elon Musk has always been pretty transparent about Tesla’s mission, which is to accelerate the advent of sustainable energy. Having enough batteries to enable such a transition is key to this goal. With this in mind, the potential innovations that Tesla will be discussing in Battery Day — a larger form factor that would allow the company to produce fewer cells to get the same amount of energy; a tabless cell design that could make production easier; dry electrode tech that could greatly increase the production capacity density of each battery; and a cell-to-pack design that should allow the production of batteries with less equipment at less cost — could ultimately pave the way for electric vehicles and energy storage products that are significantly better than the industry standard today.
The Roadrunner project in Fremont is expected to be a central component of Tesla’s battery manufacturing plans, with attendees to the event being shown just how fast the company could produce its battery cells using its in-house production process. Elon Musk seems to be hyping the Roadrunner line recently on Twitter as well, when he made references to a game called “Factorio,” which happens to be a title focused on growing and maintaining advanced, efficient factories.
The Million-Mile Battery
The million-mile battery has been heavily speculated for Battery Day. Tesla’s electric cars are already capable of lasting long despite heavy use, but with batteries and powertrains that could last a million miles, the company could create a generation of vehicles that are designed to be always operational for an extended period of time. Million-mile batteries are then crucial for Tesla’s plans to roll out a Robotaxi service, which involves vehicles traveling long distances every year.
The Plaid Powertrain
With Tesla’s battery innovations in mind, speculations are high that the company would unveil its first vehicles that would carry its next-generation cells on Battery Day. Among Tesla’s ongoing projects, the Roadrunner cells seem to be a perfect match for cars like the Plaid Model S, Plaid Model X, and next-generation Roadster. All three vehicles have been confirmed by Elon Musk to feature the company’s upcoming “Plaid Powertrain,” which is something that has been heavily teased for some time now. Interestingly enough, updates on Tesla’s Plaid vehicles have been pretty scarce lately, making an announcement on Battery Day somewhat likely.
Watch Rob Maurer’s full Tesla Battery Day predictions in the video below.
Tesla has reached a notable benchmark in its autonomous driving program after its Robotaxi fleet surpassed one million miles of unsupervised operation. The company made the announcement during its Cybercab event in Austin on September 3.
Tesla Vice President of AI Ashok Elluswamy told attendees he was happy to report the fleet had achieved one million miles of unsupervised Robotaxi operation as a testament to safety.
The new total marked a sharp increase from the 380,000 unsupervised miles Tesla disclosed during its second-quarter 2026 earnings update in late July.
In roughly six weeks, the company added about 620,000 miles. That acceleration followed Tesla’s decision to remove in-vehicle safety monitors from most of its operations outside the San Francisco Bay Area.
Credit: Tesla
Tesla first launched Robotaxi service in Austin in June 2025 with safety drivers present. It later began fully unsupervised rides and expanded into Dallas, Houston, Miami, Orlando, and Tampa. The San Francisco Bay Area remains the exception, where a safety monitor still rides in the vehicle under California permitting rules.
The company has not released a city-by-city breakdown of the one million unsupervised miles.
The milestone arrived as Tesla began offering public Cybercab rides in Austin. The purpose-built vehicle has no steering wheel or pedals and is designed only for autonomous ride-hailing. Production versions joined the existing fleet of modified Tesla vehicles already operating in the service.
Tesla’s unsupervised mileage is growing at a double-digit weekly rate according to earlier company comments, yet its fleet size remains modest compared with established competitors. Waymo has accumulated more than 200 million fully autonomous rider-only miles. Tesla has described its own unsupervised operations as having recorded zero notable incidents in the period leading up to the July update.
The one-million-mile figure reflects Tesla’s shift from supervised testing to broader driverless service in multiple states. It also highlights the company’s strategy of using both existing Model Y vehicles and the new Cybercab to scale its network.
Credit: Tesla
Whether the rapid recent growth continues will depend on further city expansions, regulatory approvals, and the performance of the purpose-built Cybercab in everyday paid rides. Tesla has not specified how many of the latest miles involved the new vehicle versus the rest of the fleet.
The announcement underscores Tesla’s progress toward a larger robotaxi network while illustrating the remaining gap in total autonomous experience relative to longer-operating rivals.
Tesla AI lead Ashok Elluswamy said this week that 24-hour Robotaxi service is close. Replying on X to a rider who wanted Cybercab trips all night, he wrote that the capability would arrive “next month or so” once “the next tech to merge on the v15 plan” is ready.
The comment landed on September 4, one day after Tesla opened public Cybercab rides in Austin. It is the clearest near-term timeline yet for overnight unsupervised operation. Tesla’s paid Robotaxi network currently runs from 6 a.m. to 10 p.m. seven days a week across Austin, Dallas, Houston, Miami, Orlando, and Tampa.
next month or so. the next tech to merge on the v15 plan will enable it.
— Ashok Elluswamy (@aelluswamy) September 4, 2026
That 16-hour window is shorter than the 6 a.m. to 2 a.m. schedule the company used for much of the prior year.
Elluswamy did not name the specific feature or say whether the change would apply first to purpose-built Cybercabs, the existing Model Y fleet, or both. He also offered no city-by-city rollout list. The link to Full Self-Driving v15 is nevertheless significant.
Tesla has described v15 as a step-change architecture with seven parallel improvement tracks and roughly ten times more parameters than earlier builds. Early versions of that software already operate on the Robotaxi fleet and contain about 40 percent of the planned gains.
By July 2026, the unsupervised fleet had logged more than 380,000 miles across six cities in two states with what the company called an impeccable safety record and no notable incidents caused by the vehicles themselves. Tesla has repeatedly argued that camera-based end-to-end neural networks, rather than extra sensors, are the core of the solution.
Overnight service would test that claim in lower-light conditions and would also raise vehicle utilization, a key variable for Robotaxi unit economics. The company has already begun using public Superchargers at night and is building dedicated Robotaxi charging sites.
Riders have asked why software must change if the cars already drive in the dark. The practical answer appears to be reliability and scale: Tesla has held back mass expansion until more of the v15 stack is merged, citing the need for higher confidence before putting thousands of unoccupied vehicles on streets around the clock.
If the next module arrives on the timetable Elluswamy sketched, 24-hour service could begin in October 2026 in at least some markets.
That would mark a shift from a daytime-bounded pilot to a service that can run whenever demand exists, including the late-night hours that have so far remained out of reach.
Tesla is beginning to roll out Full Self-Driving Supervised v14.3.9 with a new active safety layer that can take control even when the driver is operating the car manually.
Tesla AI said the software can activate FSD on the driver’s behalf when an imminent collision is detected and Automatic Emergency Braking may not be enough. It may also engage if the system detects heavy distraction or an accidental FSD disengagement.
FSD Supervised v14.3.9 starting to roll out shortly
This release includes a new active safety feature set: FSD Supervised can now activate on your behalf when an imminent collision is detected and Automatic Emergency Braking (AEB) may not be enough.
It may also engage if we…
— Tesla AI (@Tesla_AI) September 4, 2026
The capability is essentially Automatic Collision Evasion. However, unlike conventional AEB, which mainly applies the brakes in a straight line, this feature can use steering, braking, and acceleration together if the car calculates that stopping alone will not prevent impact and a safer path exists. The system may change lanes or move toward a shoulder when conditions allow, then continue driving after the immediate threat is handled rather than simply coming to a stop.
The intervention is meant as a last-resort safety net, not a replacement for attentive driving.
Tesla Full Self-Driving v14.3.7 early review: FSD saved me from an accident
Tesla’s own description still frames FSD as supervised assistance. Secondary reports on internal release notes say the feature can fire while the car is being driven manually if cabin-camera monitoring suggests the driver is not sufficiently attentive, such as reaching toward the back seat, or if FSD appears to have been turned off unintentionally.
After the emergency maneuver, the car is expected to alert the driver and request a return to manual control.
The safety case is straightforward. Many collisions happen in the last second because a driver is looking away, fumbles a control, or faces an obstacle that braking cannot fully solve. A system that can both recognize that AEB is insufficient and execute a coordinated evasive path can reduce those remaining high-severity events.
Re-engaging after accidental disengagement also addresses a practical failure mode: a small steering nudge that drops FSD at the worst moment. The advantage is a background safety net that uses the same vision stack already running in v14, instead of leaving the car solely to emergency braking once the driver is no longer in command.
The feature still depends on FSD being enabled and, according to reports, an active FSD purchase or subscription. It does not make the vehicle unsupervised. Drivers remain responsible, and Tesla has not published how often the system is expected to intervene or how it will handle false positives.
If the rollout is conservative and the false-alarm rate stays low, the update is a meaningful step: FSD is no longer only a feature the driver turns on. In the rare moments when disaster is already forming, it can step in.
Tesla crosses major Unsupervised Self-Driving milestone
Tesla Robotaxi will be a 24/7 service: here’s when
