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Tesla Semi and Roadster could be relying on a “battery breakthrough”

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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.”

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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.

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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

EVANNEX carries aftermarket accessories, parts, and gear for Tesla owners. Its blog is updated daily with Tesla news.

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Elon Musk

Why Tesla Roadster unveiling delay might have nothing to do with it flying

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tesla roadster elon musk flying
Credit: Grok

Tesla announced on Monday that the Roadster event scheduled for today would be postponed due to the need for it to be held outside.

Less than 24 hours later, CEO Elon Musk broadened that by stating it was due to high winds, immediately sending everyone into a frenzy over the Roadster’s potential ability to fly.

And realistically, it could definitely have to do with it flying, hovering, or hopping; whatever Tesla has in mind for this demonstration could not be impacted by wind. However, it might have nothing to do with the vehicle flying whatsoever, and instead could be a simple precaution, as the Roadster is a very unique vehicle with some already official specs that are just mind-blowing.

Tesla will very, very likely be showcasing both the acceleration rate and potentially even a top speed demo at the event in Waco. Both of these demonstrations, performed with a vehicle that has such incredibly fast metrics, could easily be impacted by wind as well.

Tesla Roadster event requires restricted airspace, and the FAA obliges

Top Speed Demo

At high speeds, aerodynamic forces are already overwhelmingly present. A crosswind or sudden gust adds a layer of sideways force that the tires must counter with slip angle. On a short demo course, that force can shove the car off the intended line, especially in a light car with a low frontal area and little mass to resist the push.

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Electric cars, due to their battery packs, have an advantage of an extremely low center of gravity, giving them extra stability. However, the speeds at which the Roadster could travel at the demo could spell some issues if crosswinds are present.

Gusts are worse than a steady wind because the load changes faster than a driver can smoothly correct. That shows up as weaving or a late correction. Headwinds and tailwinds can also spell disaster. Headwinds cut a measured top speed but raise the power needed to get there or maintain it. Meanwhile, a tailwind can inflate the top speed, and downforce issues could become more noticeable.

Wind also loads the body unevenly. A low car can feel light on the upwind side or see a sudden change in downforce if the gust hits a wing or diffuser at an angle. Tire temperature and pressure might stay near a normal level, but lateral grip can be lost as the vehicle is spent fighting the wind.

Acceleration Demo

Launch and 0-60 MPH runs are shorter, so the car spends less time exposed to forces that could cause things to go awry. However, the first second is very sensitive, as a crosswind at launch could yaw the car before speed builds and prior to aerodynamic impact being too great. The driver will be required to correct traction control or manage how much the wheels are spinning, which will likely be corrected automatically by some sort of traction control system within the Roadster (we are fairly certain Tesla will implement something brilliant with it).

These things could cause an unstable run.

A headwind would increase drag as speed rises, while a tailwind would do the opposite. Meanwhile, surface effects, like wind-driven dust, light debris, or even rain, could reduce grip at the exact moment the tires are asked for peak longitudinal force. Standing water plus a crosswind is a common reason an acceleration attempt might be scrapped.

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Flying or Not

No matter what Tesla has in store for the Roadster, waiting for ideal conditions is a great idea. People who follow and support the company, along with the engineers involved in the Roadster program, have been waiting nine years since the last unveiling for this moment. Everything should be ideal.

Some speculate that it’s just not ready, and that’s ridiculous. Why would Tesla even schedule the event — albeit prematurely — after nine years if it was not ready? Why would they jump the gun now?

We were all excited for today, but it truly is the most ideal thing in the world to wait two more weeks so everything, including the weather, can be perfect. The delay is simply worth it. But Tesla, seriously, make this the last one.

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SpaceX nails “Lucky 13” astronaut launch, leaning into Tesla tradition and superstition

SpaceX launched Crew-13 astronauts to the ISS Thursday, setting up a record fast Dragon docking.

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Crew Dragon sits atop Falcon 9 at sunrise on Cape Canaveral's pad 40, less than a day before four astronauts are set to launch to the ISS. (Credit: SpaceX)

SpaceX launched NASA’s Crew-13 mission to the International Space Station on Thursday morning, getting four astronauts to orbit despite a forecast of thunderstorms and gusty winds that had threatened to push the flight to Friday.

Falcon 9 lifted off from Space Launch Complex 40 at Cape Canaveral Space Force Station at 11:10 a.m. ET carrying Dragon Grace, NASA confirmed. On board are NASA commander Jessica Watkins, NASA pilot Luke Delaney, Canadian Space Agency astronaut Joshua Kutryk and Roscosmos cosmonaut Sergey Teteryatnikov. The first stage booster, B1101, landed at Landing Zone 40 beside the pad on its third flight after previously supporting Crew-12 and a Starlink mission.

It was the first spaceflight for Delaney, Kutryk and Teteryatnikov. Watkins, who flew on Crew-4 in 2022, became the first NASA astronaut to launch aboard a Crew Dragon twice.

Before launch, the crew rode to the pad in Teslas, a tradition on NASA’s SpaceX crew flights since 2020. This time the cars carried specialty plates reading “Lucky 13.” Watkins said the mission patch leans into the number on purpose, as a nod to Apollo 13 and the resilience of that crew.

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Grace is now on a short trip to the station. Docking at the forward port of the Harmony module is scheduled for about 7 p.m. ET, roughly 7 hours and 50 minutes after liftoff, which Space.com notes would be the fastest Crew Dragon transit to the ISS yet. Most Dragon flights take around 15 to 24 hours to catch the station. Hatch opening is planned for 8:25 p.m. ET.

The launch came more than two weeks later than originally planned. An oxidizer leak was found in Grace’s propulsion system in August, and NASA and SpaceX added time for tests. That pushed back the return of Crew-12, which has been aboard the station since February and is now set to splash down off Southern California next week. Crew-13 is expected to stay about six months.

SpaceX rescue mission for stranded ISS astronauts nears end — Here’s when they’ll return home

SpaceX already holds NASA orders for crew rotations through Crew-17, while Boeing is preparing an uncrewed Starliner flight to the station as early as December.

Crew-13 was only the first of three SpaceX launches planned for Thursday, as Teslarati previewed on Wednesday. A Falcon 9 launched its Transporter-18 mission from California today, where Google will be launching its first orbital artificial intelligence (AI) test satellite. Meanwhile, Falcon Heavy is set to launch the classified NROL-97 mission for the National Reconnaissance Office from Launch Complex 39A at 11:53 p.m. ET. Its two side boosters will return to Landing Zones 1 and 2, which means Central Florida could hear up to three sonic booms in a single day. The busy stretch follows Starship’s Flight 14 on Monday, which reached orbit for the first time.

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Tesla moves forward on Wireless Charging for vehicles

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Credit: Tesla | X

Tesla has moved its Wireless Charging efforts for its electric vehicles forward, as it had a new patent published today, one that it submitted back in March.

The patent describes a system for detecting foreign objects on the wireless charging pad under varying temperatures, aiming to mitigate any undesired results that could come from something being on top of the charging pad.

The abstract of the patent states:

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“The present disclosure relates to methods and systems that can reliably detect foreign objects on a wireless charging pad under varying temperatures. In some examples, an object detector can utilize a set of inductive coils included in resonant tanks, and excite the resonant tanks using signals in a range of frequencies including or near a nominal resonant frequency of the resonant tanks. The object detector can detect a metal object based on resistance of a coil increasing and inductance of the coil decreasing. By analyzing the shifts and/or distributions in resonant frequencies and output magnitudes (e.g., output voltage peaks), the object detector can distinguish between changes of frequencies and magnitudes caused by temperature and those caused by foreign objects to accurately detect the foreign objects.”

The object detection system will utilize a set of inductive coils included in resonant tanks, and “excite the resonant tank using signals in a range of frequencies including or near a nominal resonant frequency of the tanks.” Metal can be detected by an increase in the coil’s resistance and a decrease in the coil’s inductance.

By analyzing shifts or disruptions in resonant frequencies and output magnitudes, the system can detect foreign objects. These types of safeguards need to be implemented through the normal operation of the charging pads.

Tesla says its Cybercab wireless charging efficiency is ‘well above 90%’

Tesla plans to utilize wireless charging with Cybercab and Robotaxi-enabled units to help streamline the fully autonomous experience from A to Z. The last thing the company wants to do is have any sort of small obstruction preventing the rider from experiencing Robotaxi as intended.

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