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Tesla Semi

Discussion in 'TSLA Investor Discussions' started by jhm, Jul 25, 2016.

  1. mongo

    mongo Well-Known Member

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    They could do it that way. I was thinking 4 separate sub packs and a commonized charger sitting between the charge port and sub-packs.
    On the 3, the extra electricity electronics live above the cells under the rear seat. The semi doesn't have that space so it would cut into battery capacity to integrate them. Also makes replacement of the charger more costly. Also only need 1 or 2 12V converters and such.

    A 480V 3 phase @ 50 A AC connection would give a 500kWh charge overnight, that might be handy for a company with more locations than trucks.
     
  2. scaesare

    scaesare Well-Known Member

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    And what's more the entire pack represents ~75KWh of capacity, served by the single 9.6KW charger.
     
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  3. dhanson865

    dhanson865 Active Member

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    Number 4 and 5 on that layout hides the internals, The board referenced as the HVC - High Voltage Controller and/or power conversion unit is the 10KW charger in addition to its other duties.

    inside it looks like [​IMG]

    and

    [​IMG]
     
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  4. dhanson865

    dhanson865 Active Member

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    The High Voltage Controller (HVC) and Power Conversion System (PCS) are highly integrated on the Model 3. There is no way to separate out the charger function from the other functions that manage the pack.

    Going down that line of though each of the 4 packs on the Semi will have its own HVC / PCS. No way they are going to design entirely new PCBs just for the Semi when the Model 3 PCBs are being made in high quantities and the Semi is not. No way they are going to try and balance cells or modules through an outside of the pack connection. No way they would move controllers outside the pack that are needed locally.
     
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  5. Lessmog

    Lessmog Active Member

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    All this is laid out in almost painful detail here Tesla Model 3 - NextGen Battery - EVTV Motor Verks if you have two or three hours worth of attention. Instructive but designed to scare away all but the most enthusiastic. Jack explains in his next post We've Upped Our Game...so UP YOURS. - EVTV Motor Verks

     
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  6. mongo

    mongo Well-Known Member

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    There are pros and cons to both approaches. My thinking is that integrated is nice, but it takes up cell space. It also seems like, due to scale, having the charger/ brains sub-functions individually replaceable is better than needing to pull 200kWh of pack to fix it. The integration on 3 gives a tight package, less exterior harnesses, and reduces Fremont assembly steps. It also makes service easier. One swap replaces much of the HV components. Less time spend troubleshooting: drive unit, pack, compressor, or heater. Semi needs to combine the sub packs for the other functions on the tractor.

    Cell monitoring/ balancing is done at the module level with a separate PCB that provides a pre-processed data link output.
    Only control needed at the pack is the pyro (self monitoring) and the HV contactors.

    HVC and PCU are separate modules, so one could be included but not the other. They are also not so much integrated as co-located. I'm guessing the HVC is the smarts for charge port/ contactor/ safety circuitry. For the semi, that all needs to be somewhat centralized (or else coordinated and distributed) so reusing the 3 may not make sense functionality wise regardless of current volumes.

    The charging function is separable (as shown on X/S), charge port connects to charger with a bypass contactor set for Megacharging, charger connects to pack, communications live on separate harness.
     
  7. scaesare

    scaesare Well-Known Member

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    #1887 scaesare, Jun 5, 2018
    Last edited: Jun 5, 2018
    I too am a bit of the opinion that the Model 3 pack as a whole would likely not be used in the Semi. Modules, yes (a whole slew of the 25-group modules perhaps). But pack, including integrated charger, no... it's form/layout is pretty tailored to the model 3.

    Now, that having been said, I could see them using the same charger guts to build a larger onboard charger for the semi (in much the same way that multiple chargers could be ganged inside a Model S or a Supercharger).
     
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  8. mongo

    mongo Well-Known Member

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    Yah.
    Dimension wise, I don't think the 3 modules as they are would fit well. However, the design of the module lends itself to arbitrary lengths/ capacities, and the monitor board can likely handle an arbitrary number of cells with extra components.

    The 3 diagram shows a 3 phase charging connector, so they could potentially use 4 units (integrated or not) to feed the (theoretically) four sub-packs.
     
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  9. jhm

    jhm Well-Known Member

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    Freightliner Announces Electrified Versions Of Its Popular Heavy-Duty & Medium Duty Trucks | CleanTechnica

    I'm a bit surprised that this semi, the eCascadia, needs 550kWh to get a mere 250 mile range, 2.2kWh/mile. It also is very slow charging. This crock pot takes 90 minutes to get an 80% charge, 300kW. Oddly enough the smaller truck, the eM2 with 325kWh for a 230 mile range, takes just 60 minutes for a 80% charge. Its not clear to me why they cant do charging in parallel so that the eCascadia would do a 80% in 60 minute too.

    The eCascadia looks like a turkey that won't fly in the commercial market, configured mostly to confirm the biases set against electrying semis. The eM2 may be workable if the price is right.

    I think Freightliner is making a rookie mistake by simply cramming batteries into the body of an ICE vehicle. They are obviously not experienced, savvy or committed enough to build an electric vehicle from the ground up. I think this will be apparent once the Tesla Semi hits the market. I think that will come in around 900 kWh for 600 mile range and be capable of a 80% charge in 20 to 30 minutes, plus have Megacharging infrastructure. This is possible because Tesla is optimizing the whole vehicle and infrastructure around the drivetrain. By comparison, the eCascadia would be designing an iPod in the shape of an 8-track cassette to that it can be popped into a 8-track tape player. C'mon Freightliner, diesel truck nostalgia is not going to cut it.
     
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  10. jhm

    jhm Well-Known Member

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  11. SwTslaGrl

    SwTslaGrl Member

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    #1891 SwTslaGrl, Jun 23, 2018
    Last edited: Jun 23, 2018
  12. mongo

    mongo Well-Known Member

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    I'm thinking that isn't the semi due to the multi piece unibody construction. Semi at reveal looked like frame rails.
    The concave frame rail looks like they were trying for a lower profile, and the metal wheel arch body panel does not match the flat side approach with single piece bumper and wheel flare cover. (Of course prototype != production).

    I'm thinking Y. What are they testing? It looks like they load up the frame to the point of deformation, so is that the reaction point for the rear axle? If so, then likely not the pickup due to truck vs bed shape.
     
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  13. Electroman

    Electroman Active Member

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    Two words: Pickup truck
     
  14. mongo

    mongo Well-Known Member

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    Could be. It seems like rear axle region, in which case the void above it seemed excessive for a bed. However, apparent size could be deceiving and normal trucks have room there also to clear the pumpkin.
     
  15. jhm

    jhm Well-Known Member

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    The shape of that fender is suggestive of the Semi front fender. There is the letter "Y" written on this, but that could be for anything.
     
  16. mongo

    mongo Well-Known Member

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    Likely a 3 undergoing P torque testing. The loading point points to being rear section, Semi has one piece plastic front bumper & wheel flare cover, and you can see the rear door opening in the upper right of the image.
     
  17. SwTslaGrl

    SwTslaGrl Member

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    Yes it was my first thought too. Other posters here suggested it's the Model 3 right rear fender, and without rear doors you "see through" the car.

    Edit: thanks @mongo
     
  18. mongo

    mongo Well-Known Member

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    Happy to be repetitive, but most of that comes from @JRP3
     
  19. Esme Es Mejor

    Esme Es Mejor Member

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    I’ve been posting lately about Tesla acquiring Ford (& perhaps others after that), but I think I have a much more feasible suggestion: Navistar (NAV).

    They have a market cap of about $4.2 billion, so they could likely be acquired for less than $5 billion (all stock, I would presume). They have capacity to build about 250,000 class 8 semis annually, and an additional 150,000 or so class 6 & 7 trucks. Their manufacturing facility is in Ontario, Canada, and they have a semi-truck joint venture in China. They also have about $1 billion in cash & cash equivalents.

    I don’t claim to be an expert in M&A, but this seems promising. If Tesla is confident that they have plenty of room to build the Semi in the GF, then no need. But if they could use the extra capacity (& the extra cash), this seems like a good fit.
     
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  20. SwTslaGrl

    SwTslaGrl Member

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