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Tesla Semi-Truck

Tesla Semi-Truck

My god. Good idea. Hopefully tesla doesn't make a truck WITHOUT the input from REAL truck drivers like that other company did. Company owners love it but real drivers aren't.
NO clue what real drivers go through on a day to day. How many times a driver has to actually get out of their vehicle, open the door to back up. no doing that in that other company's vehicle. I took a brand new cascadia evolution to a farm and got stuck in the mud and had to be pulled by a farm tractor 1/2 mile, everybody that went there did. do these companies do any REAL WORLD testing before they say "Here's the truck of the future, don't do xxxxxx with it." that other electric truck doesn't even have a door on the passenger side! "Hey mr. DOT officer come walking around into traffic to get in my truck to look at my logs." LOL how often does that happen? lmao. Ever been to a shipper or receiver that's got a call box? best keep a long stick in there with ya or get out of your seat and walk around to the door and get out. We need the work outs but damn that's some serious lack of real world input. looks cool though but ill never buy or drive one.

jordanrichard | 02/05/2017

What "other" company are you talking about?

David N | 02/05/2017

Yes, what is the "other" company

Bighorn | 02/05/2017

What drivers?

dyefrog | 03/05/2017

I'm guessing he's referring to Nikola Motor Company.

https://nikolamotor.com/one

evan | 03/05/2017

{{3*3}}

brando | 04/06/2017

side note: they may not need drivers.

Perhaps always need independent drivers for those farm deliveries etc. but ports to warehouse to box stores not so much.

georgehawley.fl.us | 04/06/2017

@coyote: Tesla has a Marketing guy, Jerome Guillen, running the Semi design project. He also has mechanical engineering and semi development background.

Jerome Guillen has served as our Vice President, Worldwide Service and Deliveries since March 2015, and previously served as our Vice President, Worldwide Sales and Service from April 2013 to March 2015 and as our Model S Program Director from November 2010 to April 2013. Prior to joining us, Mr. Guillen served as Director, Business Innovation at Daimler AG, an automobile manufacturer, from September 2007 to November 2010. Mr. Guillen also served as Director, New Product Development at Freightliner LLC, a manufacturer of trucks and heavy duty vehicles, from September 2002 to September 2007. Mr. Guillen holds a Ph.D. in mechanical engineering from the University of Michigan, in addition to a dual degree in energy technologies from Escuela Tecnica Superior de Ingenieros Industriales in Madrid and in mechanical engineering from Ecole Nationale Superieure de Techniques Avancees in Paris.
Source: Tesla on 04/22/2015

There is little chance with his credentials that he will overlook obvious feature requirements for the Tractor Design to my mind.

The big questions about the project that intrigue me are the following.

1. Is it going to be battery-powered unlike the other company's truck?
2. If so, I think it will need something like 450 kWh to tow a heavy load for more than 200 miles.
That raises the charging question. I'm thinking that they might build in 6 Model 3 75 kWh battery packs and when they stop to charge they Supercharge the 6 packs independently and simultaneously so that it only takes the amount of time required to charge a single pack. That requires over 700 kW of power at the truck stop. Interesting.
3. If they use a couple of 250 hp equivalent drive units, they will have 500 hp available which seems adequate. But they also need to develop something like 1500 - 2,000 lb.-ft. of torque to get the big rig rolling with a full load. How do they do that? With a transmission?

bb0tin | 04/06/2017

@georgehawley
1. Tesla has already said it will be battery powered
2. It requires less than that
3. They will use more than two Model 3 motors

georgehawley.fl.us | 05/06/2017

Now we know.

georgehawley.fl.us | 05/06/2017

Bernie: please check me out on some numbers.
Wikipedia reports rolling resistance coefficient of car tires to be .0062 to .015, semi truck tires to be in the range of .0045 to .008.
As an example the MX consumes about 200 wh/mile to overcome rolling resistance, about 10% more than the MS. At about 5,000 lbs. I make this out to equate to a coefficient of rolling resistance of .005 per tire, a little better than the wiki low end. Let's say that Tesla will do as well with truck tires, say .0035 per tire. The MX burns about 50 wh/mile per tire carrying about 1250 pounds per tire.

The maximum truck weight in the U.S. Is 80,000 pounds or 4400 pounds per tire for an 18 wheeler about 3.5 times that of the MX but the coefficient of rolling friction is less for truck tires. Therefore the friction force per tire is about 2.5 times that for the X tire. That's 125 wh/mile per tire for the truck. That's 2.25 kWh per mile for an 18 wheeler or 450 kWh for 200 miles, equivalent to 6 75 kWh battery packs and I haven't accounted for air friction.

Please show me where I have erred. I don't profess to be an expert in the area of rolling friction.

bb0tin | 05/06/2017

@georgehawley
There is a simpler way than that.
There are many sources giving the mpg of semis, including modern streamlined semis.
Compare this to a car and you can get the ratio of mpg for the two.
Apply this ratio to the existing Tesla cars and you get the expected required number for a Tesla Semi.

georgehawley.fl.us | 05/06/2017

80,000 pound streamlined truck might get a little better than 10 mpg.

Car with Diesel engine might get around 50 mpg on the highway.

That's a 5:1 ratio. Not sure what it proves as the relative efficiency of the engines comes into play as well as transmission gear ratios at highway speeds.

But this suggests that the truck needs about 5 times as much energy capacity as the car.

In battery talk a 90 kWh car becomes a 450 kWh truck for maybe a 250 mile range??

In the same ballpark as the blizzard of numbers above. But we will know more in September.

If Tesla can make compelling cars, they ought to be able to do similar magic with trucks.

bb0tin | 05/06/2017

@georgehawleg
Streamlined trucks get better than that.
You also said 450kWh for 200 miles, not 250.
As I said "2. It requires less than that".

georgehawley.fl.us | 06/06/2017

Right--250. Of course, one could expect a driver to have a little left in the tank, so to speak, when they stop to recharge.

I know next to nothing about trucks, as you can tell, but it is fun to learn a little. Mercedes boasts about getting 12 mpg for a 60,000 pounder so I reduced that by 17% to 10 mpg for 33% increase to 80,000 pounds. Seemed a fair assumption for this little exercise.

Whether it is 350, 400, 450, 500, whatever kWh, it is going to be by far the biggest production assembly of Lithium-ion cells for automotive purposes in history, I think. The charging strategy has to be multiple sub-packs in parallel. That ought to dim the lights at the truck stops.😀

georgehawley.fl.us | 06/06/2017

Sorry, 65,000 pounds.

bb0tin | 06/06/2017

@georgehawley
Tesla is expecting to be making 500,000 Model 3 at the end of 2018, and several million per year after that.
Given that the Model 3 will likely be about 60kWh on average, and assuming a semi has about 600kWh, that means that you expect Tesla to be making 50,000 semi's at the end of next year say, or about how many Model S or Model X they make per year now. Once they are making millions around 2020, it means that your think they will be making hundreds of thousands of semi trucks then too.

There is no need to have sub-packs for charging purposes. As has been explained to you before when you have brought it up, splitting a pack into sub-packs makes no difference to the maximum charge rate. Packs are already split into cells and modules. That being said, there are other benefits of having multiple packs such as economy of production, flexibility in positioning packs in the truck, and swapability.

georgehawley.fl.us | 06/06/2017

I don't think I was talking about volume of production. I meant that an individual truck will be the largest assembly of Li-ion cells in one vehicle.

I wasn't clear about the battery organization. What I meant was that in order to charge the truck's battery in a reasonably short time, they could hook up, say 6 cables, each supplying 120 kW to one unit of 75 kWh of battery cells as a way pushing 720 kW into the truck. If they have six drive units, then each battery pack-drive unit combination might be identical to the Model 3 set, HW and SW.

Apologies to the OP for usurping the thread.

georgehawley.fl.us | 06/06/2017

I think I may be wrong on the idea about the Tesla truck having the largest array of batteries. The 60 foot, Model E2 Proterra bus goes up to 600 kWh according to their website. https://www.proterra.com/products/catalyst-40ft/

Takes up to 5 hours to charge.

bb0tin | 06/06/2017

@georgehawley
There is no need to hook up 6 cables. That is not how power supply works. Whether it is running a trolley bus, train, supplying a building etc, you run larger cables rather than more of them. I expect that Tesla will use underbody 350kW+ single source charging. When I say 350kW+ I mean potentially a lot more than 350kW.

bb0tin | 06/06/2017

Proterra also have up to 660kWh
https://www.proterra.com/products/catalyst-40ft/

Frank99 | 06/06/2017

bb0tin -
Yes, that could happen, but it involves engineering design and development of new battery systems, interconnects, chargers, and other infrastructure. Re-using the Model 3 packs, motors, chargers, and existing Supercharger technology would shave millions off the development cost, and a year or more off the development time, compared with the "perfect" solution.

Sometimes pragmatism wins. We'll find out which way they went when they unveil it.

Marty1234 | 06/06/2017

The battery exchange experiment for tesla cars didn't work but it seems perfectly suited for commercial trucks. Drive 250-350 miles then exchange battery packs in a few minutes and there off..

bb0tin | 06/06/2017

@Frank99
Isn't the Model 3 a brand new pack?
Isn't the 100D a brand new pack?
Won't the 2170 packs for S/X be new?
Hasn't Tesla been working on the semi for a long time?
Please supply a link where Tesla says they will use Model 3 battery packs.

Frank99 | 06/06/2017

Sure, but you're ignoring the other parts of my comment, which is all the pieces around the battery. If you build a (for argument's sake) 800V, 500 kwh battery, you have to re-engineer the charging circuitry, the motor drive electronics, the contactors, the 12V battery charger, the supercharger-like external charging electronics, etc. That's a lot of work. The question of whether you put a super-super-charger connector on the side, or on the underbody, is really a minor part of the issue. Whether that super-super-charger connector or underbody connector makes two connection, or seven, is a trivial side effect of the major design decision of using six independent batteries, or 1 big battery.

The engineer in me agrees that doing it "right" would mean doing all the redesign, building a 500+kwh battery, and charging it as a single entity; the "but we don't have an infinite budget" side of me says "well, you could do it substantially cheaper and faster by simply duplicating Model 3 bits and pieces". Like I said, we'll see at the reveal.

The information that's available is from the Tesla Q1 investor call. You can look that up, but the germane section is:
Elon Musk: "Most of that semi is actually made out of Model 3 parts by the way. It’s actually using a bunch of Model 3 motors..."
No discussion of batteries, but it would be hard to parse "most of.." as excluding them...

bb0tin | 06/06/2017

@Frank99
Firstly, I did not ignore your other parts.
Secondly, Tesla may keep the pack(s) at 400V.
Thirdly, when you are building a new vehicle, on a new chassis, the redesign you are talking about for 800V is a minimal proportion of the time and cost required. It costs far more to build just the production line.
Lastly, your quote does not support your claim that Tesla is going to use Model 3 packs.
PS:
I have already stated on this thread that Tesla is going to use Model 3 motors when I earlier posted:
"3. They will use more than two Model 3 motors"

georgehawley.fl.us | 06/06/2017

Using Model 3 components takes advantage of the economies of scale of those elements. Also reduces R&D costs and shortens the design and parts certification lead time. Supposing the Model 3 drive units to operate at 350 volts like the S and X designs infers a 350 volt delivery /400 volt charge constraint on the battery pack. You could have n independent battery packs, each associated with a drive unit with n small charging cables.

Or you could have n packs operating in parallel as a unit with 400 volt by 300 X n amperes supercharger and a massive cable and connector unlike any in the Tesla inventory. If n is 6 for example, that's over 700 kW of power!

trx430ex | 06/06/2017

What was most interesting said on the call is what is not spoken, then it came to me, tire size, 22.5 the most efficient for the drive tran? If we are going to go tourque'ie, then were talking about a tire size north of 43, big tires, longer distance, more efficient. Would also like the semi group to design by length of the 22.5 design, everything from a box truck, out to a 45 foot RV, it can all scale the same.

Frank99 | 06/06/2017

>>>does not support your claim that Tesla is going to use Model 3 packs
You must have mistaken me for someone else. I haven't made such a claim.

trx430ex | 06/06/2017

A quarry tire?, A railroad locomotive wheel, not on steel, but on asphalt & concrete. Was puzzling not seeing any rail access urgency. That means we are past rail efficiency/cost? To the better logistics of (poorly maintained) asphalt. Altho asphalt, is empty at night, logistics currently underutilized.

bb0tin | 06/06/2017

@Frank99
You just posted ">>>does not support your claim that Tesla is going to use Model 3 packs. You must have mistaken me for someone else. I haven't made such a claim."

But you previously posted:
"Re-using the Model 3 packs, motors, chargers, and existing Supercharger technology would shave millions off the development cost, and a year or more off the development time, compared with the "perfect" solution."

and then followed it with:
"The information that's available is from the Tesla Q1 investor call. You can look that up, but the germane section is:
Elon Musk: "Most of that semi is actually made out of Model 3 parts by the way. It’s actually using a bunch of Model 3 motors..."
No discussion of batteries, but it would be hard to parse "most of.." as excluding them..."

i.e. You believe that Elon's statement supports it being likely (or hard to be unlikely) that Model 3 battery packs will be used.
Elon's statement does not support that claim at all, so my statement "Lastly, your quote does not support your claim that Tesla is going to use Model 3 packs" is correct.

bb0tin | 06/06/2017

@Frank99
To be clear, Elons statement does not support any claim about the Model 3 batteries whether it be likely, very likely, unlikely or very unlikely. Any claim you make relating the batteries is unsupported Eon's statement .

Frank99 | 06/06/2017

I'm afraid I don't follow your leap of logic. You go from "you believe...supports it being likely" to "your claim". I claimed nothing stronger about batteries than Elon's statement is consistent with using Model 3 batteries in the Semi.

Now, I hope for a statement from you that you made a mistake.

bb0tin | 06/06/2017

@Frank99
Are you trying to claim that you quoted Elon without any intent to claim that his statement supports, in any way, that Model 3 batteries would be used in the semi?
If the answer is that you did not, then why quote his statement, because it would have been immaterial.

bb0tin | 06/06/2017

To be clear "Elon's statement is consistent with using Model 3 batteries in the Semi." is false.
Also, Elon's statement is consistent with using hamster batteries in the Semi, is also false.

Ross1 | 07/06/2017

https://www.theverge DOT com/2017/6/6/15750228/elon-musk-tesla-model-3-model-y-twitter-red-wine

This covers truck, model 3 and other new products

georgehawley.fl.us | 07/06/2017

or three groups of 2 75 kw packs in parallel with 3 400 kw charging hook ups?

Following Tesla is so much fun. Lots of opportunity for speculation and then the surprises that follow.

Frank99 | 07/06/2017

bb0tin -
To be clear "Elon's statement is consistent with using Model 3 batteries in the Semi." is completely true.

And, despite your best efforts to put words into my mouth, I am claiming nothing about what Tesla WILL do with batteries in the semi; I am simply, in the spirit of speculation about an unrevealed product, discussing what Tesla COULD do and whether the various options are consistent with existing public statements. If you're incapable of differentiating COULD from WILL, then the conversation is over.

Bighorn | 07/06/2017

.

georgehawley.fl.us | 07/06/2017

@coyote: you probably heard Elon sort of answer your concern about getting input from drivers by saying that potential customers have been consulted as part of the design process, assuming those customers employ drivers and understand their requirements.

bb0tin | 07/06/2017

@Frank99
You quoted Elon in support of your statement about batteries.
Elon's statement does not support your claim at all. The purpose of quoting Elon was to try and support your claim, otherwise there was no point in doing so.
PS:
"Trees move in the wind" does not support your claim.
"2+2=4" does not support your claim.
They also do not contradict your claim.

Frank99 | 07/06/2017

Repeating a falsehood doesn't make it true.

I'm sure that those reading this thread will be able to ascertain whether your statements about mine are true or not, so I'll no longer participate in this derailed conversation.

bb0tin | 07/06/2017

@Frank99
Your quote from Elon, does not support, or not support, any claim that you are making. It is irrelevant.
i.e. that the quote supports your claim, is false.

trx430ex | 07/06/2017

Enough!, either work the problem or shut your pie hole.