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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.”
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Note: Article originally published on evannex.com, by Charles Morris
Tesla owners have long griped about the wireless phone charger in the Model Y and other vehicles. It often turns smartphones into miniature ovens rather than reliably topping them up.
Software engineer and Model Y owner Michał Gapiński tackled this issue head-on with a clever DIY upgrade, swapping the cooled wireless charger pad from the China-made Model YL in for the one that came standard in his vehicle.
There are several key differences between the U.S.-built Model Y’s wireless charging pad and the one that Tesla has been installing in the Model YL. The one installed in U.S.-built vehicles lacks active cooling and relies on basic heat dissipation, leading to rapid temperature buildup during charging. In contrast, the Model YL integrates a small fan for active cooling.
Will it fit? Fingers crossed, I want a first YL charger deployed in the regular juniper pic.twitter.com/wWDqSNFVkW
— Michał Gapiński (@mikegapinski) June 2, 2026
This design maintains lower temperatures even in warm ambient conditions, though it does not support faster Qi2 charging on iPhones. The connector matches exactly, making physical swaps feasible on compatible consoles, but coding is required to enable full functionality.
Owners in the U.S. have complained about the wireless charging pad, with many reporting that overheating is fairly common. Within 20 or 30 minutes of placing a phone on the wireless charging pad, many have reported overheating messages on their phones, which halt charging and essentially turn the pad into a fancy place to rest your phone.
Many owners have opted to simply plug their phones into a charging cord. Tesla has acknowledged the problem by releasing several solutions for owners, including a relatively new feature that allows you to simply turn off the charging and simply act as a holder for your phone while driving.
Gapiński said that he sourced the cooled pad affordably from China, and it cost under $200 for the part.
He removed the existing console charger, swapped in the new unit, confirming a perfect connector fit, and handled the trim differences. Since the parameter isn’t fully secured, he enabled it through custom coding outside official Toolbox.
Connector is identical, she fits, now time to code it. https://t.co/Y9idgDrpCq pic.twitter.com/uwwgq6blg7
— Michał Gapiński (@mikegapinski) June 2, 2026
The fan activates quietly, blending with AC and seat cooling. He reported the installation was effective and the wireless charging pad worked perfectly; it even kept the phone cool as it stayed at just 86 degrees Fahrenheit. Many times, the wireless charging pad will bring the phone’s temperature well above 100 degrees, sometimes even being relatively hot to the touch.
The retrofit worked, no issues. First Model Y with a cooled wireless charger! No QI2/faster charging on the iPhone but it does not boil the phone even when it is 30 degrees outside.
The fan kicks in, it is not audible especially with the air conditioning and seat cooling. The… https://t.co/JOyR8Tb1Yo pic.twitter.com/kJcYhQIlYq
— Michał Gapiński (@mikegapinski) June 2, 2026
This retrofit highlighted an elegant, owner-driven solution to a factory shortcoming. It is expected that Tesla will begin installing the cooled charging pads into new cars in the U.S. soon, and hopefully, it will offer some sort of retrofit service or kit to owners here who want to use the charging pad effectively.
For those who love to tinker, it’s an accessible upgrade, proving that innovation thrives beyond the production line.
The Tesla Roadster unveiling could be coming “in a few weeks,” according to the company’s Chief Designer Franz von Holzhausen, who said at the Tesla Takeover Europe Event in Austria that the all-electric hypercar could finally make its way to the production line after years of anticipation.
Von Holzhausen delivered the news just days after The Information reported that Tesla planned to push the Roadster unveiling to August. It was slated for both April and May of this year, but now it seems the company is leaning toward a late Summer event to cap off the heat with perhaps its most anticipated vehicle of all-time.
🚨 Tesla Chief Designer Franz Von Holzhausen, speaking to the crowd at Tesla Takeover Europe, said at the event that the Roadster is coming “in a few weeks,”
Multiple attendees have confirmed this pic.twitter.com/B1v6yb2Geq
— TESLARATI (@Teslarati) June 6, 2026
Franz has been with Tesla since 2008, and has played a pivotal role in the iconic design language the company has utilized with its vehicles. Speaking to the crowd in Austria virtually, von Holzhausen’s comments injected fresh excitement into a project that has been plagued by delays for nine years.
The second-generation Roadster promises to redefine supercar standards. Tesla’s website still highlights ambitious targets: 0-60 mph in under 1.9 seconds (with optional SpaceX thruster pack potentially achieving 1.1 seconds or less), a top speed exceeding 250 mph, and a range of about 620 miles.
Equipped with a tri-motor all-wheel-drive setup delivering over 1,000 horsepower, the four-seater aims to blend blistering acceleration, everyday usability, and innovative features like cold gas thrusters for short-hop capabilities, technology that will combine the project with SpaceX.
But years after the company promised to start production, which was slated for 2020, the timeline for the Roadster has continued to shift.
Tesla has strung along those who have put $50,000 deposits down, as well as fans and enthusiasts of the company who have been long awaiting the company to bring forth a car truly designed for the human driver, and not autonomy. The Roadster is more than just a halo vehicle for Tesla; it showcases the company’s ability to push the boundaries while incorporating synergies from other Musk companies.
However, it has to make it to production, which is something Musk and Co. have pushed back repeatedly.
As Tesla navigates Robotaxi development and broader autonomy goals, the Roadster serves as a reminder of its performance roots. If von Holzhausen’s timeline holds, fans could witness this engineering marvel by late June or early July 2026. Whether a full unveiling, demo, or initial deliveries, it marks a milestone for electric supercars.
Tesla has reportedly pushed the unveiling of the Roadster once again, but there are also evidently new details about the event that the company plans to show off.
The Information reported this morning that Tesla will now unveil, for the second time, the next-generation Roadster in August, a further delay from the multiple timeline that the company had previously stated.
The report has not been confirmed or denied by Tesla at any capacity.
It also states the unveiling event will take place in Texas, the same place that Tesla executives revealed in May would be the place of manufacture for the company’s highly-anticipated supercar, which boasts a top speed of over 250 MPH and 650 miles of range, according to its website.
Tesla is also expected to showcase the SpaceX package, which will be used for faster acceleration and potentially hovering capabilities, at the unveiling event, the report states. Musk has always planned for this to happen, but now it seems it is more realistic than ever
The report also states the Roadster unveiling is planned for August pic.twitter.com/By26XZIJzU
— TESLARATI (@Teslarati) June 5, 2026
The Roadster has had its unveiling date and manufacturing date pushed back on many occasions. It was set to start production in 2020, but the COVID-19 pandemic crippled supply chain operations, forcing Tesla to push its timeline back considerably.
However, COVID has been over for some time, and Tesla has still not managed to successfully schedule and execute an unveiling event, which is something fans and enthusiasts, as well as those who have put down a $50,000 deposit, have been waiting for.
The vehicle was close to completion last year, but Musk truly wanted Lars Moravy and Franz von Holzhausen to push the limits of the Roadster. In July of last year, Moravy said:
“Roadster is definitely in development. We did talk about it last Sunday night. We are gearing up for a super cool demo. It’s going to be mind-blowing; We showed Elon some cool demos last week of the tech we’ve been working on, and he got a little excited.”
It is important to note two things: Tesla has not confirmed these details, and the company has regularly pushed these dates back. Until Tesla sends out formal invitations with a concrete date, taking any unveiling event reports with a grain of salt is a good idea.
Tesla owner fixes common feature complaint with crafty DIY retrofit
Tesla exec says Roadster unveil is soon — for real this time
