News
Tesla Semi and Roadster could be relying on a “battery breakthrough”
Elon Musk and Tesla have made some bold claims for the new Tesla Semi and Roadster. Those who understand batteries have been scratching their heads trying to figure out how the company can deliver the specs it’s promising – and concluding that the only possible way is some as-yet-unannounced advancement in battery technology.
Musk says the Tesla Semi will be able to haul 80,000 pounds for 500 miles, and recharge to 400 miles in 30 minutes, which would revolutionize the trucking industry. As for the Roadster, its promised 0-60 acceleration of 1.9 seconds effectively shuts down every one of the world’s baddest supercars, and its touted 620-mile range would be double that of any EV produced to date.
However, industry experts are questioning Tesla CEO Elon Musk’s touted range and charging capabilities, saying the specifications defy current physics and battery economics.
According to Bloomberg, analysts at Bloomberg New Energy Finance point out that Tesla Semi’s announced specs would require a battery capacity of between 600 and 1,000 kilowatt hours (6-10 times the size of the largest Model S battery). Using current technology, an 800 kWh battery pack would weigh over 10,000 pounds and cost more than $100,000. That’s just for the battery – Tesla has said its entire truck will start at $150,000. It seems plain that Tesla is counting on falling battery prices to square the circle. “The first Tesla Semis won’t hit the road until late 2019,” Bloomberg points out. “Even then, production would probably start slowly. Most fleet operators will want to test the trucks before considering going all-in. By the time Tesla gets large orders, batteries should cost considerably less.”
It isn’t just the capacity of the battery that’s causing analysts to wear out their calculators – Musk’s claim that the Tesla Semi will be able to add 400 miles of charge in 30 minutes would require a charging system 10 times more powerful than Tesla’s current Supercharger – which is already by far the most powerful in the industry.
Tesla Semi Megacharger port could support 1 MW of power.
“I don’t understand how that works,” said Bloomberg New Energy Finance EV Analyst Salim Morsy. “I really don’t.” Tesla’s current generation of Superchargers have a power output of 120 kilowatts and can add about 180 miles of range to a Model S battery in 30 minutes. To meet Tesla’s charging claim for the Semi would require the promised Megacharger to deliver an output of at least 1,200 kW.
Perhaps Tesla’s biggest bombshell is the promise that it will guarantee truckers electricity rates of 7 cents per kilowatt hour, which Bloomberg estimates could translate to fuel savings of up to $30,000 a year. Musk says that adding solar panels and battery packs at the charging stations will account for at least part of the cost reduction. However, BNEF’s Salim Morsy insists that Tesla will have to heavily subsidize those electricity rates – he estimates that Tesla will pay a minimum of 40 cents per kWh. “There’s no way you can reconcile 7 cents a kilowatt hour with anything on the grid that puts a megawatt hour of energy into a battery,” Morsy said. “That simply does not exist.”
Of course, that’s no different from what Tesla does for its current Supercharger network, offering free electricity to many customers, while paying almost $1 per kWh to produce it, according to Morsy’s estimate.
And how about that Roadster? To deliver its promised range of 620 miles, it will need a 200 kWh battery pack, twice the size of Tesla’s largest currently available pack. Mr. Morsy predicts that Tesla will stack two battery packs, one on top of the other, beneath the Roadster’s floor.
Even with a double-decker pack however, it’s hard to escape the conclusion that Tesla is counting on improving battery tech to make the Roadster, like the Semi, feasible. Battery density has been improving at a rate of about 7.5 percent a year, and that’s without any major breakthrough in battery chemistry.
“The trend in battery density is, I think, central to any claim Tesla made about both the Roadster and the Semi,” Morsy said. “That’s totally fair. The assumptions on a pack in 2020 shouldn’t be the same ones you use today.”
A massive battery pack not only enables greater range – it’s also a key element in the Roadster’s world-beating 0-60 acceleration. Jalopnik’s David Tracy spoke with battery expert Venkat Viswanathan, a Mechanical Engineering Assistant Professor at Carnegie Mellon, who says that the 1.9-second figure actually seems reasonable.
Viswanathan explains that the power output of a motor is limited by the power draw from each battery cell. Because the Roadster’s pack is double the size, the power draw may not be that much more than that of a Ludicrous Model S.
Viswanathan told Jalopnik that the most modern battery cells offer specific energy of about 240 watt-hours per kilogram. Using that assumption, the Roadster’s 200 kWh battery pack should weigh roughly 1,800 pounds, a huge advance over the previous-generation Roadster. With clever use of lightweight materials, the Roadster could still come out under the nearly two-ton curb weight of the Nissan GT-R, an acceleration benchmark among sports cars.
Viswanathan concludes that a 0-60 time of 1.9 seconds and a range of 620 miles are quite feasible, although there are several other factors that will come into play – much depends on the vehicle’s tires and aerodynamics.
Meanwhile, at least one analyst thinks Tesla’s latest revelations (or claims, or fantasies, depending on your point of view) have implications that go far beyond the Semi and the Roadster. Michael Kramer, a Fund Manager with Mott Capital Management, told Marketwatch that he suspects improved battery capacities and charging times could make their way into all future Tesla vehicles.
“I’d have to imagine that Tesla has figured out how to put this technology on all of their cars, which means every car could get a full charge in under 30 minutes,” Kramer wrote. Once the Model S “is equipped with the 200 kWh battery pack in the new Roadster, which I can’t imagine is too far down the road, the range issue for the Tesla is officially dead.” (Elon Musk has said that Models S and X will not get physically larger packs, but improved energy density could increase capacity while keeping the size of the pack the same.) Someday soon, Kramer says, “The Model S would likely be able to drive further on one charge than a car on a full tank of gasoline.”
===
Note: Article originally published on evannex.com, by Charles Morris
News
Anti-Tesla union leader ditches X, urges use of Threads instead
Tesla Sweden and IF Metall have been engaged in a bitter dispute for over two years now.
Marie Nilsson, chair of Sweden’s IF Metall union and a prominent critic of Tesla, has left X and is urging audiences to follow the union on Meta’s Threads instead.
Tesla Sweden and IF Metall have been engaged in a bitter dispute for over two years now.
Anti-Tesla union leader exits X
In a comment to Dagens Arbete (DA), Nilsson noted that her exit from X is not formally tied to IF Metall’s long-running labor dispute with Tesla Sweden. Still, she stated that her departure is affected by changes to the platform under Elon Musk’s leadership.
“We have stayed because many journalists pick up news there. But as more and more people have left X, we have felt that the standard has now been reached on that platform,” she said.
Jesper Pettersson, press officer at IF Metall, highlighted that the union’s departure from X is only indirectly linked to Tesla Sweden and Elon Musk. “Indirectly it does, since there is a lot of evidence that his ownership has caused the change in the platform to be so significant.
“We have nevertheless assessed that the platform had value for reaching journalists, politicians and other opinion leaders. But it is a microscopic proportion of the public and our members who are there, and now that value has decreased,” Petterson added.
IF Metall sees Threads as an X alternative
After leaving X, IF Metall has begun using Threads, Meta’s alternative to the social media platform. The union described the move as experimental, noting that it is still evaluating how effective the platform will be for outreach and visibility.
Pettersson acknowledged that Meta also does not operate under Sweden’s collective bargaining model, but said the union sees little alternative if it wants to remain visible online.
“In a perfect world, all large international companies would be supporters of the Swedish model when they come here. But unfortunately, the reality is not like that. If we are to be visible at all in this social media world, we have to play by the rules of the game. The alternative would be to become completely invisible, and that would not benefit our members,” he said.
Despite many recent rumors and various reports, Elon Musk confirmed today that SpaceX is not developing a phone based on Starlink, not once, but twice.
Today’s report from Reuters cited people familiar with the matter and stated internal discussions have seen SpaceX executives mulling the idea of building a mobile device that would connect directly to the Starlink satellite constellation.
Musk did state in late January that SpaceX developing a phone was “not out of the question at some point.” However, He also said it would have to be a major difference from current phones, and would be optimized “purely for running max performance/watt neural nets.”
Not out of the question at some point. It would be a very different device than current phones. Optimized purely for running max performance/watt neural nets.
— Elon Musk (@elonmusk) January 30, 2026
While Musk said it was not out of the question “at some point,” that does not mean it is currently a project SpaceX is working on. The CEO reaffirmed this point twice on X this afternoon.
Musk said, “Reuters lies relentlessly,” in one post. In the next, he explicitly stated, “We are not developing a phone.”
Reuters lies relentlessly
— Elon Musk (@elonmusk) February 5, 2026
We are not developing a phone
— Elon Musk (@elonmusk) February 5, 2026
Musk has basically always maintained that SpaceX has too many things going on, denying that a phone would be in the realm of upcoming projects. There are too many things in the works for Musk’s space exploration company, most notably the recent merger with xAI.
SpaceX officially acquires xAI, merging rockets with AI expertise
A Starlink phone would be an excellent idea, especially considering that SpaceX operates 9,500 satellites, serving over 9 million users worldwide. 650 of those satellites are dedicated to the company’s direct-to-device initiative, which provides cellular coverage on a global scale.
Nevertheless, there is the potential that the Starlink phone eventually become a project SpaceX works on. However, it is not currently in the scope of what the company needs to develop, so things are more focused on that as of right now.
Tesla has added a notable improvement to its Dashcam feature after complaints from owners have pushed the company to make a drastic change.
Perhaps one of the biggest frustrations that Tesla owners have communicated regarding the Dashcam feature is the lack of ability to retain any more than 60 minutes of driving footage before it is overwritten.
It does not matter what size USB jump drive is plugged into the vehicle. 60 minutes is all it will hold until new footage takes over the old. This can cause some issues, especially if you were saving an impressive clip of Full Self-Driving or an incident on the road, which could be lost if new footage was recorded.
This has now been changed, as Tesla has shown in the Release Notes for an upcoming Software Update in China. It will likely expand to the U.S. market in the coming weeks, and was first noticed by NotaTeslaApp.
The release notes state:
“Dashcam Dynamic Recording Duration – The dashcam dynamically adjusts the recording duration based on the available storage capacity of the connected USB drive. For example, with a 128 GB USB drive, the maximum recording duration is approximately 3 hours; with a 1 TB or larger USB drive, it can reach up to 24 hours. This ensures that as much video as possible is retained for review before it gets overwritten.”
Tesla Adds Dynamic Recording
Instead of having a 60-minute cap, the new system will now go off the memory in the USB drive. This means with:
- 128 GB Jump Drive – Up to Three Hours of Rolling Footage
- 1TB Jump Drive – Up to 24 Hours of Rolling Footage
This is dependent on the amount of storage available on the jump drive, meaning that if there are other things saved on it, it will take away from the amount of footage that can be retained.
While the feature is just now making its way to employees in China, it will likely be at least several weeks before it makes its way to the U.S., but owners should definitely expect it in the coming months.
It will be a welcome feature, especially as there will now be more customization to the number of clips and their duration that can be stored.
Anti-Tesla union leader ditches X, urges use of Threads instead
Elon Musk confirms SpaceX is not developing a phone
