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It's marketed as a truck that has 300 mile range fully loaded. If it can't make a 240 mile trek, even one climbing the Sierra Nevadas, that will not look good on the 300 mile claim. I would become a claim that has lots of caveats on it, like "only good when road is flat and weather is fair." Likewise the 500 mile truck had better make a 400 mile trip, even one that climbs to the Continental Divide. Ever skeptic out there will be posing less then 300 or less then 500 routes that the trucks won't be able to do.
BTW, it is significant that Tesla is marketing these trucks by range, not battery capacity. So it will be Tesla's responsibility to pack enough kWh in these trucks to deliver nameplate range. It's different marketing a vehicle by battery capacity. Sure my S has 85 kWh, but how much range is that? Well it depends. This puts the burden on the buyer to figure out what range they think it will really deliver. I think Tesla has recognized that they need to turn this around and put the burden back on itself to deliver the range under all reasonable conditions.
You are 100% wrong. The range of S, or X or 3 or the Semi is based on a flat terrain , decent weather conditions and 65mph speed. And the expectation is, elevation, temperature, wind and driving speed will all impact the range - positively or negatively
So what next? the 300 Semi should guarantee a 300 mile range at full load at -30F, going up a mountain at 75 mph?
I hear your point, But hauling 80k pounds from sea level to Sparks, NV (4,413 ft) takes 133 kWh in pure potential energy. You don't just give that away.
Based on my favorite number of 1.6kWh/ mile that is 83 miles of range or an additional 28% on the 300 mile range. Reversed, the 300 miles version really does 383+ flatland. So 300 is really 400, 500 is really 650?
Edit: Fremont to Sparks is 260miles (350 with the elevation), so the 300 may be able to squeak it out.
You only took elevation into consideration. If you take subzero temps with a little headwind. No way it can make that trip.
I just had an idea ... does anyone know if 'other' semis have a thing resembling a built in scale?
Tesla semi has very fine (numerical) control over power delivery and torque sensors.
They for sure have speedometer, a clock and a computer.
This means the truck is capable of instant calculation of its gross weight including cargo. It only needs to measure the acceleration it got out of known (already measured) torque at very low speeds.
Using this data and destination point, navigation should be able to calculate required energy to get there.
Tesla semi has very fine (numerical) control over power delivery and torque sensors.
They for sure have speedometer, a clock and a computer.
This means the truck is capable of instant calculation of its gross weight including cargo. It only needs to measure the acceleration it got out of known (already measured) torque at very low speeds.
Using this data and destination point, navigation should be able to calculate required energy to get there.
Keep in mind that Donner Summit has to be crossed at 7239 feet on the trip on I-80 from Sparks to Fremont (7227 feet traveling eastbound). Interstate 80 in California - Wikipedia
Yes, I understand that. I drive a Model S. But it is marketed as an 85, not a 265. When you actually name a vehicle in reference to its range, not its capacity, you are making a pretty strong claim. Yes, customers will have some tolerance for extreme conditions that interfere with range. But I do think Tesla is setting very high expectations here, and truckers are going to need very high reliability.
Another thing to consider is that Tesla is setting a 1 million mile warrantee. For the 300 to deliver that much longevity, it will likely need a bigger pack than need for a typical 300 mile range. Frequent deep cycling cannot be allowed to undermine longevity. So I think the 300 mile range will be more of software limit than a physical limit on the battery. The cost of a larger physical pack is made up for in lower cost of warrantee to Tesla. So if the range is software limited and priced to include warrantee, there may be no real problem with using more capacity on an uphill trip than downhill. Suppose for example that the battery is software limited to go down to a 20% state of charge on a typical flat trip, but on an uphill trip it can go down to 1% SOC if necessary.
The rated range need not be a simple multiple of kWh in the pack. Rather the rated range could be adjusted for driving conditions, say grade and temperature. Now if a driver has a hot foot and wastes energy, that could count against the dynamic rated range. Basically, if the driver uses autopilot or drives just as efficiently, the rated range could be based on physical miles not the energy needed to travel those miles. So think of it this way, the rated range going from Freemont to Sparks can be made equivalent from Sparks to Fremont. The software is doing the necessary calculations to map rated range to physical mile and is optimizing the cycling of the battery to do both trips with minimum degradation to the life of the battery. Going uphill simply requires a deeper cycle than going downhill. We don't want truckers having to make mental calculations about this and make suboptimal choices about charging depth. Rather we want AI to optimize this to minimize Tesla warranty exposure.
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Good point, that is 220 kWh or 137 Range miles at 200 miles into the trip. 337 miles needed to get there, then it gets some kWh back on the down slope.
You forgot nighttime.
and trafficCold weather has less of a percentage impact on an 80 thousand pound tractor trailer than an aerodynamic passenger car.
Batteries hold less energy in very cold weather, and air is denser as temps drop. Both of these have the same cumulative effect on a Semi as much as a car.
i wouldn't be surprised if a 500 mile truck only can only do 350 in cold weather climbing over the mountains. And if you add ice and snow on the ground, that adds more rolling resistance. 350 is a reasonable bet on subzero temps.
i wouldn't be surprised if a 500 mile truck only can only do 350 in cold weather climbing over the mountains. And if you add ice and snow on the ground, that adds more rolling resistance. 350 is a reasonable bet on subzero temps.
I can go with 350 on a really cold day.
Semi is roughly half aero half rolling in terms of power usage. Air density change from 65F to -30 F is 22%, so 11% range hit there. Say clear roads most of the time with 20% higher rolling, that is 10% of total. 10kW of heater to keep pack/driver warm over 6 hours is 8% of 800kWh pack. So 29% reduction. 350 mile range.
I'm hoping heater load will be lower than that due to pack/ motor self heating and reduced surface area. Tire change vs temp was a guess.
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One thing about the semi I keep thinking about is the idea of a million mile guarantee with 500 mile range. This is not possible in the current EV paradigm where batteries degrade, range is hugely impacted by weather and elevations. So it got me thinking how? One easy way would be to have a larger battery where capacity is dynamically unlocked based on need. Let's assume there was a breakthrough on NMC cells to improve energy density that allows 5000 cycles with less then 10% degradation. So the pack size would be oversized by 15% which would allow for degradation, anti-brick and a small reserve "tank" past 0%. Based on the trip and elevation, extra capacity could be dynamically unlocked. When the vehicle knows exactly where you are going and the schedule, it can smartly allow access to extra range that will eventually degrade to the point where it's no longer available, but would be available for the first few years on an as needed basis. Even ice vehicles degrade and have limitations on weather. The goal here would be reliability and consistency where it counts for semi owners. Having a slightly larger battery wouldn't cost much more and might just be required to meet the other guarantees and provide a great experience for customers.
It would be great PR if the empty Semi back to Sparks only use up the energy regenerated with full payload on the way down. Similar to the Iron Ore Line in Sweden ("The regenerated energy is sufficient to power the empty trains back up to the national border" Iron Ore Line - Wikipedia ). The Semi never has to Supercharge!
From the TMCer who talked to them, they are both 300 mile versions. I'm guessing for more/ deeper cycles.
This is essentially what I was suggesting in my last post.
Say you have 1MWh in the physical battery, but it is dynamically "unlocked" only to allow 500 physical miles. Perhaps in ideal conditions only 1.2 kWh/mile is needed. That is only 60% of the pack is needed. So the software knows to keep the SOC within 20% to 80%. The driver only sees and has access to the middle 60%. But suppose that under extreme conditions (weather and grade), 1.8 kWh/mile is needed. This unlock the middle 90% of the battery and the software holds SOC between 5% and 95%.
In all cases, the driver is limited to 500 physical miles but the fraction of the battery dynamically unlocked varies from about 60% to 90% of original 1MWh capacity. This could be why Tesla spoke of a 2kWh/mile upper bound. This may be sufficient for 99% of all driving conditions, but Tesla will want fairly strong control over depth of cycling to minimize abuse to the battery. Tesla can't put a 1 million mile warranty out there and allow drivers to abuse packs. They've got a software layer between the driver and the pack.
Isn't it a one million mile breakdown guarantee as opposed to a part failure/ wear warranty?
If Telsa can use 80% capacity packs for Grid applications, then replacing packs (for nominal fee) might be more cost effective than over sizing the pack for lifetime degradation.
Routes will be analyzed before tractor sales to enure customer happiness and charging infrastructure (including weather). I do not think this level of dynamic routing (different grades) will be in play for a while.
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