Tesla’s ambitious 4680 cell program has been pivotal for its vehicle roadmap - and in particular, for the Cybertruck. Bonnue Eggleston, Tesla’s Senior Director for the 4680 cell project at Tesla, recently sat down with Sandy Munro on Munro Live, offering valuable insights into cell development, manufacturing hurdles, and Tesla’s future trajectory. You can watch the video in its entirely below.
The 4680 cell, like many batteries, is characterized by its dimensions: 46mm in diameter and 80mm long. Tesla is currently producing the 2nd generation of the 4680 - internally known as the Cybercell - which is shipped with every variant of the Cybertruck. This Gen 2 variant is a considerable step up from Gen 1 - whose limited production was cancelled following the slow charging issues with the 4680 Model Y.
Prototypes are Easy; Production is Hard
Bringing the 4680 from a concept cell to mass production hasn’t been easy, but according to Tesla, it has now become Tesla’s cheapest cell per kWh. Eggleston emphasized in the video that scaling up was an immense challenge - and required an extreme attention to detail.
With a team possessing a broad skill set, it took considerable effort to bring the 4680 to life, starting from the raw electrode material and progressing through the crucial formation process.
Breaking Barriers
To overcome these hurdles, Eggleston’s team leaned into innovation and focused on new processes that had not been utilized in the battery world yet. The groundbreaking new dry electrode process is the key here, which eliminates the use of toxic solvents and large ovens required in traditional production methods. This reduces internal factory footprint, while also being cleaner and safer, building a better cell from the ground up.
Complementing this, Tesla has also been developing a custom electrolyte formulation in-house, tailored specifically for their anode, cathode, and separator materials, all aimed at expanding their deep vertical integration.
This vertical integration has been key to the 4680 program, and Tesla has further extended it, with in-house production of components like cell cans serving to optimize the process and reduce waste. Eggleston also pointed out the unique terminal design on the 4680, which allows for easier and more reliable welding, contributing to the high production output that Tesla is aiming for.
Sustainability
On the sustainability front, Tesla has been hard at work recovering and recycling materials right from the manufacturing line to minimize waste. Eggleston highlighted this as part of Tesla's effort to promote sustainability, which ties in with the environmental benefits gained from avoiding solvents in the dry electrode process.
Structural Battery Packs
While the 4680 is intrinsically linked to the Cybertruck, we expect Tesla to expand this to its future vehicles eventually - whether through use of the specific cell format, or the technologies learned through its development. Eggleston noted that the efficiency of the Cybertruck is partly due to his team’s cooperation and work with the vehicle team. The structural battery pack minimizes weight and provides additional support and protection to the cabin and occupants.
4680 in the Future
Eggleston expressed a considerable amount of confidence in Tesla’s 4680 program and the progress - citing significant improvements in throughput, yields, and product quality since he took leadership.
He acknowledged the ambitious targets that Tesla and Elon have set - and mentioned that the use of metrics like headcount per gigawatt helps drive production efficiently. This metric essentially measures labor efficiency – producing more battery capacity (gigawatt-hours) with fewer people indicates a more streamlined and cost-effective manufacturing process.
While Eggleston hinted at future developments, and we have previously heard of Tesla working on even more cells for the future, the battery technology race has been progressing rapidly around the world. While Tesla has been pushing 4680 production and deploying 325kW-capable Superchargers (and soon 500kW), they continue to face challenges from the competition.
Brands like China’s Zeekr are demonstrating new LFP batteries capable of charging from 10-80% in under 10 minutes, while achieving sustained speeds of 400kW+. Currently, the Cybertruck can only sustain the 325kW cap speed for a few minutes at best, resulting in a sub-par charging curve compared to upcoming competitors.
Tesla will have to focus on developing and producing new cells that maintain that cost-competitive advantage the 4680 has built, while also achieving faster charging speeds across its entire lineup. For now, these new faster charging speeds are restricted to the Cybertruck, but with refreshes for the Model S and Model X on the horizon, we expect that Tesla’s updated flagship vehicles will make the best use of this tech until it is ready for the rest of the lineup.
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With Tesla’s first major expansion of the Robotaxi Geofence now complete and operational, they’ve been hard at work with validation in new locations - and some are quite the drive from the current Austin Geofence.
Validation fleet vehicles have been spotted operating in a wider perimeter around the city, from rural roads in the west end to the more complex area closer to the airport. Tesla mentioned during their earnings call that the Robotaxi has already completed 7,000 miles in Austin, and it will expand its area of operation to roughly 10 times what it is now. This lines up with the validation vehicles we’ve been tracking around Austin.
Based on the spread of the new sightings, the potential next geofence could cover a staggering 450 square miles - a tenfold increase from the current service area of roughly 42 square miles. You can check this out in our map below with the sightings we’re tracking.
If Tesla decides to expand into these new areas, it would represent a tenfold increase over their current geofence, matching Tesla’s statement. The new area would cover approximately 10% of the 4,500-square-mile Austin metropolitan area. If Tesla can offer Robotaxi services in that entire area, it would prove they can tackle just about any city in the United States.
From Urban Core to Rural Roads
The locations of the validation vehicles show a clear intent to move beyond the initial urban and suburban core and prepare the Robotaxi service for a much wider range of uses.
In the west, validation fleet vehicles have been spotted as far as Marble Falls - a much more rural environment that features different road types, higher speed limits, and potentially different challenges.
In the south, Tesla has been expanding towards Kyle, which is part of the growing Austin-San Antonio suburban corridor spanning Highway 35. San Antonio is only 80 miles (roughly a 90-minute drive) away, and could easily become part of the existing Robotaxi area if Tesla obtains regulatory approval there.
In the East, we haven’t spotted any new validation vehicles. This is likely because Tesla’s validation vehicles originate from Giga Texas, which is located East of Austin. We won’t really know if Tesla is expanding in this direction until they start pushing past Giga Texas and toward Houston.
Finally, there have been some validation vehicles spotted just North of the new expanded boundaries, meaning that Tesla isn’t done in that direction either. This direction consists of the largest suburban areas of Austin, which have so far not been serviced by any form of autonomous vehicle.
Rapid Scaling
This new, widespread validation effort confirms what we already know. Tesla is pushing for an intensive period of public data gathering and system testing in a new area, right before conducting geofence expansions. The sheer scale of this new validation zone tells us that Tesla isn’t taking this slowly - the next step is going to be a great leap instead, and they essentially confirmed this during this Q&A session on the recent call. The goal is clearly to bring the entire Austin Metropolitan area into the Robotaxi Network.
While the previous expansion showed off just how Tesla can scale the network, this new phase of validation testing is a demonstration of just how fast they can validate and expand their network. The move to validate across rural, suburban, and urban areas simultaneously shows their confidence in these new Robotaxi FSD builds.
Eventually, all these improvements from Robotaxi will make their way to customer FSD builds sometime in Q3 2025, so there is a lot to look forward to.
For years, the progress of Tesla’s FSD has been measured by smoother turns, better lane centering, and more confident unprotected left turns. But as the system matures, a new, more subtle form of intelligence is emerging - one that shifts its attention to the human nuances of navigating roads. A new video posted to X shows the most recent FSD build, V13.2.9, demonstrating this in a remarkable real-world scenario.
Toll Booth Magic
In the video, a Model Y running FSD pulls up to a toll booth and smoothly comes to a stop, allowing the driver to handle payment. The car waits patiently as the driver interacts with the attendant. Then, at the precise moment the toll booth operator finishes the transaction and says “Have a great day”, the vehicle starts moving, proceeding through the booth - all without any input from the driver.
If you notice, there’s no gate here at this toll booth. This interaction all happened naturally with FSD.
While the timing was perfect, the FSD wasn’t listening to the conversation for clues (maybe one day, with Grok?) The reality, as explained by Ashok Elluswamy, Tesla’s VP of AI, is even more impressive.
It can see the transaction happening using the repeater & pillar cameras. Hence FSD proceeds on its own when the transaction is complete 😎
FSD is simply using the cameras on the side of the vehicle to watch the exchange between the driver and attendant. The neural network has been trained on enough data that it can visually recognize the conclusion of a transaction - the exchange of money or a card and the hands pulling away - and understands that this is the trigger to proceed.
The Bigger Picture
This capability is far more significant than just a simple party trick. FSD is gaining the ability to perceive and navigate a world built for humans in the most human-like fashion possible.
If FSD can learn what a completed toll transaction looks like, it’s an example of the countless other complex scenarios it’ll be able to handle in the future. This same visual understanding could be applied to navigating a fast-food drive-thru, interacting with a parking garage attendant, passing through a security checkpoint, or boarding a ferry or vehicle train — all things we thought that would come much later.
These human-focused interactions will eventually become even more useful, as FSD becomes ever more confident in responding to humans on the road, like when a police officer tells a vehicle to go a certain direction, or a construction worker flags you through a site. These are real-world events that happen every day, and it isn’t surprising to see FSD picking up on the subtleties and nuances of human interaction.
This isn’t a pre-programmed feature for a specific toll booth. It is an emergent capability of the end-to-end AI neural nets. By learning from millions of videos across billions of miles, FSD is beginning to build a true contextual understanding of the world. The best part - with a 10x context increase on its way, this understanding will grow rapidly and become far more powerful.
These small, subtle moments of intelligence are the necessary steps to a truly robust autonomous system that can handle the messy, unpredictable nature of human society.
