Tesla Semi- obvious that primary battery could go in trailer.

Discussion in 'Semi' started by 101101, Nov 11, 2017.

  1. 101101

    101101 Active Member

    All this talk about contraint on battery seems so misguided. We have 1100 mile city busses being delivered now. The primary battery could go under the floor of the trailer improving center of gravity and aerodynamics. A powerpak could sit in the front of the trailer. I get that there are ultimate weight limits but they are a function of weight distribution and you can go 2 trailers to spread even more. Could sit where cab sits. If you had all of that range might be beyond best in class

    If you're charging trailer a cable so heavy it needs a robotic arm is not an issue- could just drop down over head. If you wanted to go modular its should be easier with trailer side loader or bottom dropping or even rolling out the front and back.

    So easy with trains too. Trains have been electric drive for decades. Tank and dump trucks too. You simply replace diesel engines and fuel tanks with batteries'- direct retrofit. And you put more batteries in battery cars. We've had full electric freight locomotives in some applications like munitions factories since WWII or before.
    And of course solid state batteries will arrive making all of this so much more compelling that it already is and its already beyond terminal.

    Battery replacement isn't an issue anymore. Musk says everything but rockets will go full electric soon and Tony Seba says by 2025. That is everything.

    The entire globe is on Paris now and Trump seems unlikely to make it trough even half of a term. Overriding any US veto. The follow on admin will quite plausibly come despite Pense et al before the next POTUS election and almost no chance Repubs prevail (only reason there in now us because Hillary was talking that same WWIII starting in Iran to save obsolete petrol that Romney was) just like with China accelerating US will likely rejoin with accelerated timeline to make up for Trumps idotic delay which means petrol bans. Obama's legacy is that he put the steps in place to kill petrol- sould of been done a long time ago but after the last petrol collapse (2007 was a petro collapse over derivatives ensuring petrol) causing austerity with a 17 trillion dollar bailout of petrol and coming so soon after prior bailouts Iraq 2, Enron, Afganistan, 911 it was clear it was time to put an end to petrarchy and its monarchical democracy nepotism and croynism. Petrol dollar scam is over. Petrol is not the energy sector anymore its just another security risk that the world is getting rid of. And the US was always behind OPEC because it was the core of the petrol dollar scam.
     
  2. Pushmi-Pullyu

    Pushmi-Pullyu Well-Known Member

    We had a guy who drives a semi tractor-trailer rig post a long comment to an InsideEVs news article, some months back... or maybe it was a year or two ago by now.

    According to him, semi fleets typically keep 5-7 trailers around for each tractor.

    The economics don't work at all for buying multiple battery packs to put into trailers for each semi tractor. Ditto for solar cells on top of the trailer.

    Semi trailers should be cheap and interchangeable. Those which are not, will be bought by very few if any trucking companies.
     
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  3. 101101

    101101 Active Member

    That is utter non sense
    The point is not to comply with petrol convention but to disrupt. Probably easily retro fit even existing trailers. Battery is just another load. Steam engines used to carry coal cars- tried and true.
     
  4. Pushmi-Pullyu

    Pushmi-Pullyu Well-Known Member

    Rejecting reality does not actually change reality. It just marks you as someone who prefers wishful thinking to actual facts.

    Yes, and those coal tenders generally stayed with one steam locomotive as part of a matched set... unlike a semi tractor-trailer rig. That's a failed analogy.
     
  5. 101101

    101101 Active Member

    You don't have any facts seem like a paid petro shill. What you offer is adhoc and stuff like "I call BS" when all you have to do is a simple search or be informed in the first place. Plus little call sign stuff like push pull with camels or yaks as in push news propagand or the other "feed the trees" as in feed the eco trolls. To good cop bad cop.
     
  6. Pushmi-Pullyu

    Pushmi-Pullyu Well-Known Member

    Dave, this conversation can serve no purpose anymore. Goodbye. -- HAL 9000, "2001: A Space Odyssey"

    Oh, I just remembered that on this forum, you can block seeing the posts of people you find obnoxious. Time to find out how that works!
     
  7. Domenick

    Domenick Administrator Staff Member

    Just a reminder, feel free to attack arguments, but not members personally. While I've never met @Pushmi-Pullyu in person, I'm pretty comfortable asserting that he is not a "paid petro shill." He has a long history of comments on the InsideEVs website.

    Regarding his avatar, that is the famous creature from the fictional (of course) Dr. Doolittle series. I don't think it's meant to have a special significance with regard to his electric vehicle advocacy.

    For what it's worth, I tend to side with his argument about the practicality, generally, of putting packs in trailers. Although I haven't driven tractor trailers, I do have a lot of experience behind the wheel of large straight trucks and familiarity with the logistics industry.

    From my perspective, I can see the appeal of such a solution, and it could actually work for some applications, but it falls down in terms of broad usage. On the plus side, it could help with the drawback of space available for a large pack on a tractor. Also, they should have more sitting time than a tractor for recharging purposes. Finally, if packs for 700+ miles take a while to shrink down

    On the less than plus side, it would be expensive to have one installed in every trailer. My napkin math (500 kWh x $200/kWh + installation) tells me not to be surprised by a $100,000 bill per trailer. Without some sort of large incentive package from the government, I can't see convincing many fleet operators to make that sort of investment. When a big enough pack (800+ miles or so) can be put in a tractor, the trailer solution would become unnecessary and would be abandoned on a large scale, costing fleets some amount of investment. Besides the cost of the packs themselves, it would require a good number more charging stations than if just tractors were electrified, which is another cost consideration.

    TL;DR: Without a large government program to encourage adoption of the model, not likely to happen because of expense, resistance to change, and practicality of implementation.

    It will be interesting to see if or how the Tesla Semi concept addresses the need for long distance trucking. Personally, I think the battery will be smaller for now but will make up for it with a Semi-specific high-speed charging network.
     
  8. Pushmi-Pullyu

    Pushmi-Pullyu Well-Known Member

    It's actually a very inside joke, specific to InsideEVs. Editor in chief Jay Cole once mentioned in passing that when he was spending a lot of time on the GM-Volt forum (Did he work there? Can't remember.), he would sometimes whimsically insert images of llamas into the background of photos posted there. Either he or Kdawg have done the same at least once or twice in photos posted to InsideEVs.

    Now, as true fans of the original Doctor Doolittle stories by Hugh Lofting should remember, the Pushmi-Pullyu was actually a two-headed gazelle... or more precisely, a gazelle-unicorn cross, with one of the heads having a single central horn.

    [​IMG]
    Illustration by the author, Hugh Lofting
    (Wait, something's wrong... he's showing one of my heads as a cyclops!)

    But in the 1967 Rex Harrison "Doctor Doolittle" movie, the character was changed to a two-headed llama, and fan art (such as seen in my avatar) usually follows this precedent.
     
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  9. Pushmi-Pullyu

    Pushmi-Pullyu Well-Known Member

    We can argue about the needed kWh capacity of the battery pack, but I think my own "napkin math" analysis shows pretty clearly that there will be sufficient room in a BEV semi tractor for a battery pack of sufficient size, even using my estimate of 750 miles of range. We can argue over the exact numbers, at least until this Thursday (November 16, 2017), but I don't think there is any rational reason to doubt that conclusion in my analysis.

    I've been amused at the great number of people independently suggesting that a BEV semi tractor-trailer rig should have a battery pack in the trailer. There really isn't any good reason to put one there, and several compelling reasons not to. The reason the semi tractor-trailer rig is so commonplace is because it's so useful, and the reason it's so useful is in the flexibility of being able to match (with few exceptions) any tractor to any trailer. Putting a battery pack into trailers would require certain trailers to be matched to certain tractors, instantly reducing the usefulness of the tractor-trailer rig. Plus, if trucking fleets keep 5-7 trailers in the fleet for every tractor, doesn't that mean they'd need to put 5-7 battery packs into trailers to maintain the same flexibility? One doesn't need to be an economic genius to see that no trucking fleet would spend that kind of money just to support one BEV semi tractor!
     
  10. 101101

    101101 Active Member


    Or just load the pack in as freight at the front of the trailer and remove to charge.
    I think we are somewhere between $100kwh now and $124kwh as Tesla said they are already below 124 this and that was maybe 6 months ago.
     
  11. 101101

    101101 Active Member

    I agree with most if this and saw the analysis by I think AE Randal that showed you could get 1100 miles out of the tractor alone with a modular leased battey model, he suggested the battery in different modular sizes would pull out of the front of the tractor in different modular sizes and that leasing the battery would drop the tractor price radically.

    What I am suggesting is that even if the battery were loaded as freight you might be able to get thousands of miles out of a double trailer if need be economic sweat spot or not. 1100 miles now out of Proterra city buses on a single charge.
     
  12. Domenick

    Domenick Administrator Staff Member

    If I was designing it, the pack would be slung under the belly of the trailer for stability. If could use a motorized cart to go under the trailer and remove it/shuttle it around.

    Those prices may be true at the cell level, but not at the pack level. Not yet, anyway.

    With regard to Proterra bus, that record was set at a very low speed. The company rates its nominal range as 350 miles.
     
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  13. WalksOnDirt

    WalksOnDirt Member

    I read some version of Dr. Doolittle when I was in grammar school, and I was inspired to read the version on Gutenberg (not sure they were the same) by seeing your screen name. I had no memory of the gazelle bit until I read the Gutenberg version.
     
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  14. 101101

    101101 Active Member

     
  15. 101101

    101101 Active Member

    I agree. But I was certain I saw an article that said the bus was not hypermiling. And even if it was hypermiling strange to get more than 3x nominal range out of hypermiling. On the other hand bus weighs about 6x a P100D and has about 6x the battery.
     
  16. Domenick

    Domenick Administrator Staff Member

    I found accounts of some people saying it traveled at 15 mph, but I couldn't find anything official, so I can't say what the actual speed was, though I think it was kept at a steady state, which helped. I highly doubt it was traveling at Interstate speed, which for me means 70 mph.

    Regarding the weight, it's even more than 6 P100D, (officially, the big bus with the largest battery is 33,061 lbs.) because Proterra uses a very heavy chemistry. I can't find the exact number, but at the cell level, they are around 180-190 Wh/kg. Tesla cells in the Model S and X are around 280 Wh/kg.
     
  17. Pushmi-Pullyu

    Pushmi-Pullyu Well-Known Member

    Yeah, what I wrote there was a sort of "As you know, Bob..." type of exposition, and a bit facetious. If the speaker really thinks Bob knows, then why does he need to explain things to Bob? I know my often dry humor sometimes is too subtle to be easily perceived; sorry about that! (WalksOnDirt, perhaps you remember my posts as Lensman on the old TheEEStory forum. Heaven knows I posted enough there! I presume you're also a former "Usual Suspect" on TheEEStory forum; "WalksOnDirt" isn't exactly a common screen name!)

    The Pushmi-Pullyu is just one of many fantastic animals in the stories, and there's no reason for those details to stick in anyone's mind, contrary to my facetious remark upstream.
     
  18. WalksOnDirt

    WalksOnDirt Member

    No problem there. I'm just glad to see you were aware. After reading it I had an insane desire to tell you your avatar was wrong! I soon returned to my senses.
     
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  19. Pushmi-Pullyu

    Pushmi-Pullyu Well-Known Member

    ROTFL!!
    :D ;) :p o_O

    Thanks for making my day... heck, my week, WOD!

    But I hope you understand why I'm not posting a picture of what I really look like here. Because, you know... llama stalkers!

    P.S. -- I give you points for being a bigger Hugh Lofting fan than I am.
     
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