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Featured Towing a caravan for ANY Prius?

Discussion in 'Prius, Hybrid, EV and Alt-Fuel News' started by Plugin_RK, Apr 6, 2024.

  1. Plugin_RK

    Plugin_RK Member

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    This morning I read about a caravan with it's own driving motor and own driving battery. This new type of caravan is being developed in Germany:
    Presumably, this would completely change the rating for the car since the towing vehicle is subjected to much reduced loads. I imagine that the load on the towbar/hitch would still be an issue due to:
    • control at higher speeds (sway, etc)
    • increased load on towbar/hitch since the caravan also has brakes, also
    • decreased (slightly?) load on towbar/hitch when the caravan is accelerating under its own power
    Seems like a really great development when it finally hits the mass market.
     
  2. Leadfoot J. McCoalroller

    Leadfoot J. McCoalroller Senior Member

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    The benefits of the basic idea seem obvious.

    It's going to face substantial regulatory hurdles from one market to the next, so it may be a while.

    Getting an active system to stand in for inherently stable design geometry and mass relationships is risky. Doesn't mean it can't be done, but I'd have concerns that doing that the right way would cost more than just also owning a traditional tow vehicle.

    It does strike me as an excellent development opportunity for V2V signalling and communication, because the tow car is going to need to know every little thing about what that trailer is doing.

    Heck, it might even work out better as a virtual trailer. No mechanical link, the trailer is just an EV that only knows how to drive 12" behind your bumper at all times. Volkswagen demonstrated some tech that could do something like this in the 1980s, but I don't know what they ever did with it.

    Thanks for the link!
     
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  3. Trollbait

    Trollbait It's a D&D thing

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    I don't see tow ratings for the car being changed by this. We still want the combination to be able to stop in case the trailer drive system fails.

    The Audi E-tron they used has a 1800kg tow rating in Europe, and could be over 3000 pounds in the US. Their main goal seems to be about reducing the fuel consumption penalty on the tow vehicle than exceeding the rating. Helpful for ICEs, and a big deal for EVs.
     
  4. PriusCamper

    PriusCamper Senior Member

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    Trailers have had braking assist for decades... It's not much of an advancement to put an electric motor on them and have it assist in the oppostie way braking does.

    But have you looked at the prices of the newest most advanced RV and travel trailers these days? We're talking about hundreds of thousands and even millions of dollars. These are rich people's toys... They'll never be mass produced.

    However I'm a DIY camper restoration enthusiast... Just bought this one. Spent 10 hours with a heat gun scraping all the lettering off and am prepping to paint it. Got it for $2K. It was gutted on the inside but still has all the appliances and bathroom intact and everything works. Less than 20 years old.

    It was a couple's covid project that they gave up on after they got the windows sealed up. It's pretty much as bad as a boat in terms of the amount of work required to make it nice, but to me it's renter's insurance because the cost of renting a home right now is skyrocketing! In a year or so once it's completely done the going price for this on craigs list will be in the $20K range. As in camper flipping is a new form of real estate flipping.

    And no, I am not going to tow it with my Prius... I might be fairly crazy, but not that crazy!

    f0b5804b-f334-4e4a-a4f7-48939da06cdf.jpeg 1d89b069-ccda-4eb4-ae4a-2455e2c64bab.jpeg
     
    #4 PriusCamper, Apr 6, 2024
    Last edited: Apr 6, 2024
  5. Leadfoot J. McCoalroller

    Leadfoot J. McCoalroller Senior Member

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    Funny. (but not actually funny) I was just having a conversation with a work buddy about how Northern Indiana RV manufacturers are making America look bad. Unbelievably poor quality right out of the factory. It all turns to pulp and formaldehyde the first time somebody coughs near it. Horribly predatory finance schemes to unload their inventory trash.

    On the other hand, you've got all the right motivations to rebuild it the right way. I wish you luck, housing in America is really screwed up right now and the fix won't be quick.
     
  6. PriusCamper

    PriusCamper Senior Member

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    Yeah... The build quality is horrific, more like a tent than a solid structure and up here in the Pacific Northwest once that moisture gets in and starts delaminating the walls the formaldehyde stench is awful. But because of the price of this one and because it was already stripped down on the inside, there's a chance I can save it. Once the outside is sealed up I'll have to hunt down all the moisture between exterior paneling and the walls from the inside. Way less work than had it not been stripped down on the inside already. And I got this coming Summer to ensure it dries out in every nook and cranny.
     
  7. Plugin_RK

    Plugin_RK Member

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    True, the regulatory hurdles around the globe would take a while but the enormous market potential with EV sales popularity would see the hurdles fall - assuming the price is OK if/once mass production starts.

    Owning a "traditional tow vehicle" (presumably you mean a big ICE) will certainly be cheaper in the near future. However, fuel and maintenance costs will become a consideration and the availability of fossil fuels will sometime become an issue too whereas charging stations are already becoming more plentiful. Again, assuming the price of these new caravans is OK if/once mass production starts.

    I imagine the regulatory hurdles will be much less if the caravan is actually just a traditional caravan with the "small" addition of power assist added to the wheels.

    The idea of a fully self-driving caravan rolling along behind a lead vehicle will take quite a bit more convincing, not the least because there will probably be a segment of the population dead set against it. Self-drive cars are feeling some of this opposition at present but with a lot more backing and finance behind it than self-driving caravans will ever have. It may turn out easier to just add the ability to self-drive to a campervan and let it find it's own way to the desired location.
     
  8. Plugin_RK

    Plugin_RK Member

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    I beg to differ. Once the top-of-the-range models are fitted out with drive assist to the caravan's wheels, and the kinks are ironed out then the models available to the ordinary-man-in-the-street won't be too far behind. The key will be mass production of a reliable design concept. Heck, we can could even expect to see regenerative braking for the caravan to help eek out a few more EV miles. Perhaps too there will be coupling of the batteries so that both batteries need recharging at similar times, so that the number of stops to recharge is reduced.
     
  9. Leadfoot J. McCoalroller

    Leadfoot J. McCoalroller Senior Member

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    What's the difference between a self-driving EV set up to immediately follow you vs. a mechanically connected trailer that is utterly dependent on electric propulsion, braking and stability enhancement just to be controllable?

    If they are separated when The Bad Thing occurs, they are two vehicles each (maybe) scooting to the side of the road with a certain amount of auto-braking.

    If they are bound together when the trailer has a total power failure and the leading chassis doesn't have enough raw braking capacity? Oooof.

    My point is that when you are dependent on coordinated multi-unit propulsion and braking for life safety, a hard link between the tow rig and the towed load may be more of a liability than an enhancement. You were already vitally dependent on that trailer's braking capability when it was directly coupled- why would it be different in virtual form?
     
  10. Plugin_RK

    Plugin_RK Member

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    The development of these is probably too early for publication of possible tow ratings.

    If the static and/or dynamic loading of the towbar/hitch does become the main issue, then a 3rd wheel towards the front might help. Such a 3rd wheel would perhaps only drop to the road surface when needed e.g. strong braking, but be raised off the road surface under normal conditions. This 3rd wheel could be equipped with braking to further assist strong/emergency braking, if required.
     
    #10 Plugin_RK, Apr 6, 2024
    Last edited: Apr 6, 2024
  11. Plugin_RK

    Plugin_RK Member

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    I can certainly understand your thinking here. I imagine, though, that regulators (and probably the public) will find it easier to permit power assistance for an existing, widely accepted item on the road i.e. caravans, than to permit something conceived as an entirely new concept i.e. a self-driving caravan - irrespective of whether it is following the car ahead like a well-trained pooch or completely autonomous vehicle.
     
  12. Leadfoot J. McCoalroller

    Leadfoot J. McCoalroller Senior Member

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    I concede that the appearance of a disconnected trailing unit could uh, "scare the horses" so to speak.

    I think there's a lot of room for development in this space. I reiterate that VW had a pretty successful test back in the 1980s, and all of the supporting technology they used then has improved organically since then. It'll be fun to watch.
     
  13. Trollbait

    Trollbait It's a D&D thing

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    It's a big deal for a BEV with 300 miles of range under ideal conditions without a trailer. But yes, it isn't a new idea. The trailer the space shuttle towed by the Tundra was on a self propelled trailer. The new idea here is using such to reduce fuel consumption instead of helping to move heavier loads.

    This is an Australian article about a German caravan company's project. The caravan culture is different than the RV culture. A typical 2 to 4 person caravan is in the 800kg to 1300kg range, with larger 6 person getting to 2000kg. These are lighter and smaller than the equivalent US RV trailer.

    Regulations there require overrun/surge brakes on trailers over there. Starting at 500kg or 750kg trailer weights. Safe to assume this prototype trailer had back up friction brakes to regs.

    Tow rating are based upon the capabilities of the tow vehicle. While a self propelled trailer can mean the load exceeding that, it brings in regulatory complications. Means applying rule for commercial trailers to recreational ones. Near term, best to stick with current tow ratings instead of trying to make changes before these are available.

    They're aiming for a system weight of 400kg; about 20 to 40 more kg on the tongue. This probably won't make a trailer no longer legal for a midsize car. Makes the typical caravan weights above 1200kg to 1700kg. The Audi BEV in the test isn't a large car, and was rated 1800kg towing.
     
  14. PriusCamper

    PriusCamper Senior Member

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    Buying a used Prius is affordable because they used to sell 10K a month... There's just not enough volume of sales for campers or caravans to become affordable. I've been searching for years for one I could buy for cheap and restore. The one I got is the only one I've found after years of looking. Try typing "camper" into Craigslist and you see my point pretty quick.
     
  15. bwilson4web

    bwilson4web BMW i3 and Model 3

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    I've been thinking about this as a solution for a range extender and emergency house power:
    • Small trailer
      • upload_2024-4-7_6-29-26.png
    • Salvage battery pack
      • upload_2024-4-7_6-36-15.png
    • 5th wheel
    • upload_2024-4-7_6-43-58.png
    • Trailer body (TBD)
    Operational scenario:
    • Home emergency power - parked near service access
      • Grid charging
        • Time of Day energy harvesting, buy low, use high
      • Solar charging optional
      • Powered EV wheels
    • EV range extender (aka., Cybertruck)
      • For long distance trips
    • Camper
      • 5th wheel style cabin
    A modular systems approach that starts with the trailer - battery pack and home grid interface. Initially just automatic emergency power. But software support for Time of Day minimize home electricity cost. Includes a solar array interface for charging. Estimated $6,000. Comes with motor driven wheels and control App to move around property.

    Next option is the extended battery interface to the EV. A vehicle interface, initially just using the fast DC charging when stopped. Later hack the car to allow charging while driving. Estimated $2,000 to meet utility standards.

    Then the 5th wheel trailer normally parked. But optionally, add solar cell covered exterior, This can be used for solar charging of the battery. Estimated $2,000 to $5,000. Comes with roof solar but can add all exterior walls.

    Bob Wilson
     

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  16. Plugin_RK

    Plugin_RK Member

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    Agreed. It'll be a while before these are common enough and cheap enough for me (and you? and most others?) to buy. By then my Prius PHV (/Prime) will be too long in the tooth to keep anyway (unless a good replacement battery becomes available).
     
  17. Plugin_RK

    Plugin_RK Member

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    The points you make seem all to be correct. The products portrayed in that article probably wouldn't be suitable for any vehicle with minimal tow ratings in the near future e.g. a Prius.

    However, I do feel there are grounds for optimism that within 10 to 20 years after the first serial production of a successful product using this concept there will be attempts to sell products for lighter vehicles. The towbar loading is likely to be a (solvable) issue, as mentioned in post #10 above. Most certainly the laws governing towing would have to be modified to accommodate them.

    Further into the future a (semi-)autonomous caravan/motorhome cross-over along the lines of post #9 by Leadfoot J. McCoalroller would solve the problems of weight ratings, etc. My feeling is that this is too far into the future for my traveling years.
     
  18. bwilson4web

    bwilson4web BMW i3 and Model 3

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    I have have been considering some form of camper to tow behind my Tesla. Most of them look like 'a brick wall', completely impractical. Looking for low profile, pop-ups, I came across: Sylvansport:

    upload_2024-4-14_5-34-14.png
    • Low weight, 840 lbs
    • Low profile, fits behind in our car wake
    • Curved, aero shape to front and top
    • Clever design for the ~$15,000 paid for a used BMW i3-REx
    • Tent, for fair weather
    • No plumbing or electric
    The others are too high, heavy, and not even close to aero. A step above primitive sampling or 'Kar Kamping', technically appealing like a Swiss Army knife. But this gives me an idea.

    I could rework the interior of my 2017 BMW i3-REx by taking out the rear seats and modify front seats to be reversible.. Add front and rear, side door struts and a platform with canvas cover. Hack the controls so it could 'zero drag' follow my Tesla and voila, a small, hard top and sides, camper.

    Bob Wilson
     
    #18 bwilson4web, Apr 14, 2024
    Last edited: Apr 14, 2024
  19. Leadfoot J. McCoalroller

    Leadfoot J. McCoalroller Senior Member

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    Try renting first. Great way to work out what you like and what you don't before you make the big commitment.

    Sometimes renting is the actual solution. I like RVs and campers for gadget factor, but I also know they are made of cardboard and wishes. So I never want to experience one that is more than 2-3 seasons old.

    I sure don't want to watch one depreciate all the way down around me.

    Rental solves that one for me.
     
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  20. Plugin_RK

    Plugin_RK Member

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    Agreed, if not used often. In addition to saving depreciation and maintenance incl.insurance etc., you are also saving your time and energy (possibly too storage issues when it's not in use).

    In the other hand ... We shared ownership of a campervan with another couple for about a decade. It was constantly on the road including all school holidays, many weekends, evenings, picnics, etc. Sharing ownership did mean loading/unloading more often and more cleaning but also meant sharing costs (in proportion to km traveled). It would have been completely uneconomic to rent a campervan of any size for this amount of use.

    We sold that campervan when our jobs and leisure requirements changed, and job pressures had meant that its use dramatically dropped. Once maintenance costs became very approximately similar to renting costs then we sold it. Even though the sales price was below the purchase price in $ terms, the total costs over the time of ownership for maintenance and depreciation etc. was far below the cost of renting. So, it all depends on how often (and when) the campervan/caravan/RT/etc would be used.
     
    #20 Plugin_RK, Apr 16, 2024
    Last edited: Apr 16, 2024