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 (NASDAQ: TSLA) is set to hold its Earnings Call for the first quarter of 2026 on Wednesday, and there are a lot of interesting things that are swirling around in terms of speculation from investors.
With the company’s executives, including CEO Elon Musk, answering a handful of questions that investors submit through the Say platform, fans want to know a lot of things about a lot of things.
These five questions come from Retail Investors, who are normal, everyday shareholders:
- When will we have the Optimus v3 reveal? When will Optimus production start, since we ended the Model S and Model X production earlier than mid-year? What’s the expected Optimus production rate exiting this year? What are the initial targeted skills?
- What milestones are you targeting for unsupervised FSD and Robotaxi expansion beyond Austin this year, and how will that drive recurring revenue?
- How will Hardware 3 cars reach Unsupervised Full Self-Driving?
- When do you expect Unsupervised Full Self-Driving to reach customer cars?
- When will Robotaxi expand past its current limited rollout?
Additionally, these are currently the three questions that are slated to be answered by Institutional Firms, which also answer a handful of questions during the call:
- Now that FSD has been approved in the Netherlands and is expected to launch across Europe this summer, can you discuss your Robotaxi strategy for the region?
- What enabled you to finish the AI5 tapeout early and were there any changes to the original vision? Last week, Elon said AI5 will go into Optimus and the Supercomputer, but one month ago said it would go into the Robotaxi. Has AI5 been dropped from the vehicle roadmap?
- Given the recent NHTSA incident filings, can you update us on the Robotaxi safety data? If safety validation remains the primary bottleneck, why not deploy thousands of vehicles to accelerate the removal of the safety driver?
The questions range through every current Tesla project, including FSD expansion and Optimus. However, many of the answers we will get will likely be repetitive answers we’ve heard in the past.
This is especially pertinent when the questions about when Unsupervised FSD will reach customer cars: we know Musk will say that it will happen this year. Is Tesla capable of that? Maybe. But a more transparent answer that is more revealing of a true timeline would be appreciated.
Hardware 3 owners are anxiously awaiting the arrival of FSD v14 Lite, which was promised to them last year for a release sometime this year.
The Earnings Call is set to take place on Wednesday at market close.
Elon Musk
Elon Musk reveals shocking Tesla Optimus patent detail
What looked promising on paper and in simulations failed to deliver the reliability required for a robot expected to handle delicate tasks like folding laundry, assembling electronics, or assisting in factories and homes.
Elon Musk revealed a shocking detail on the Tesla Optimus patent that was revealed last week. Despite it being made public for the first time, Musk said the company has already moved on from the design, an incredible truth about the development of new technology: things move fast.
Musk dropped a bombshell about the Tesla Optimus humanoid robot hand patent that was released last week. Musk, candidly replying to a post late at night on X, revealed that what is a new technology to many fans and insiders is actually old news to those developing the tech directly.
“We already changed the design,” Musk said. “This one didn’t actually work.”
We already changed the design. This one didn’t actually work.
— Elon Musk (@elonmusk) April 19, 2026
Patents, after all, are often viewed as blueprints for future products. Yet Musk revealed that the rolling contact mechanism—intended to provide smooth, low-friction articulation in the fingers—had already been scrapped after real-world testing exposed its shortcomings.
What looked promising on paper and in simulations failed to deliver the reliability required for a robot expected to handle delicate tasks like folding laundry, assembling electronics, or assisting in factories and homes.
The hand has been one of the biggest challenges for Tesla engineers since Optimus development started years ago. Musk has said that there is not enough recognition for how incredible and useful the human hand is, and designing one for a humanoid robot has been the biggest challenge of all.
Tesla is stumped on how to engineer this Optimus part, but they’re close
This moment underscores the persistent engineering hurdles in achieving reliable humanoid hand dexterity. Human fingers are marvels of evolution: 27 bones, intricate tendons, ligaments, and a network of sensors working in perfect harmony. Replicating that in metal and silicon is extraordinarily difficult.
Rolling contacts promised reduced wear and precise motion, but testing likely revealed issues with durability under repeated stress, grip stability on varied surfaces, or the micro-precision needed for fine motor skills.
These aren’t minor tweaks, but instead they represent fundamental challenges that have plagued robotics teams for decades. Even advanced competitors struggle here—hands remain the Achilles’ heel of most humanoids because the margin for error is razor-thin.
A fraction of a millimeter off, and a robot drops a glass or fails to button a shirt.
What makes Musk’s reply remarkable is how it signals Tesla’s direct communication style on prototype limitations. While many companies guard failures behind glossy marketing and vague timelines, Tesla openly shares setbacks.
Musk was forthcoming about the failure of this recent design. This transparency builds trust with investors, engineers, and fans. It shows Tesla treats Optimus development like true science: rapid iteration, rigorous testing, and zero tolerance for hype that doesn’t match reality.
The disclosure from Musk also highlights Tesla’s blistering pace of development. By the time the patents are published, which is often over a year after the initial filing, the technology has already evolved.
Optimus is far from a static product, and it’s a living project advancing weekly.
In the high-stakes race for general-purpose robots, Tesla’s approach stands out. Admitting a finger-joint design “didn’t actually work” isn’t a weakness—it’s confidence.
True innovation demands confronting failure head-on, and Musk just reminded the world that Optimus is being engineered that way. The next version of those hands is already in testing, and it will be better because Tesla isn’t afraid to say what didn’t work.
Elon Musk
Tesla is sending its humanoid Optimus robot to the Boston Marathon
Tesla’s Optimus robot is heading to the Boston Marathon finish line
Tesla’s Optimus humanoid robot will be stationed at the Tesla showroom at 888 Boylston Street in Boston, right along the final stretch of the Boston Marathon today, ready to cheer on runners and pose for photos with spectators.
According to a Tesla email shared by content creator Sawyer Merritt on X, Optimus will be at the Boston Boylston Street showroom on April 20, coinciding with Marathon Monday weekend. The Boston Marathon finishes on Boylston Street, and the surrounding area draws hundreds of thousands of spectators along with international broadcast coverage. Placing Optimus there puts it in front of a massive public audience at zero advertising cost.
Just got this email. @Tesla’s Optimus robot is coming to Boston.
“Join us from April 19 to 20, 2026, at Tesla Boston Boylston Street showroom to meet Optimus, our humanoid robot, for Marathon Monday. Optimus will be cheering with you on the sidelines and posing for photos.” pic.twitter.com/chxoooO2xV
— Sawyer Merritt (@SawyerMerritt) April 18, 2026
The Tesla showroom is at 888 Boylston Street, between Gloucester Street and Fairfield Street. The final mile of the marathon runs directly along Boylston Street, with runners passing the big stores before reaching the finish line at Copley Square.
Optimus was first announced at Tesla’s AI Day event on August 19, 2021, when Elon Musk presented a vision for a general-purpose robot designed to take on dangerous, repetitive, and unwanted tasks. In March 2026, Optimus appeared at the Appliance and Electronics World Expo in Shanghai, where on-site staff stated that mass production of the robot could begin by the end of 2026. Before that, it showed up at the Tesla Hollywood Diner opening in July 2025 and at a Miami showroom event in December 2025.
Tesla’s well-calculated display of Optimus gives the public a low-pressure first encounter with a robot that Tesla is preparing to soon deploy at scale. The company has previously indicated plans to manufacture Optimus robots at its Fremont facility at up to 1 million units annually, with an Optimus production line at Gigafactory Texas targeting 10 million units per year.
Tesla showcases Optimus humanoid robot at AWE 2026 in Shanghai
Musk has said that Optimus “has the potential to be more significant than the vehicle business over time,” and separately that roughly 80 percent of Tesla’s future value will come from the robot program. Whether that holds depends on production execution. For now, Boston gets a preview of what that future looks like, standing at the finish line on Boylston Street while 32,000 runners pass by.
Tesla Q1 Earnings: What Elon Musk and Co. will answer during the call
Elon Musk reveals shocking Tesla Optimus patent detail
