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Model S Hybrid?

Discussion in 'Model S: Battery & Charging' started by wipster, Jun 14, 2015.

  1. wipster

    wipster Member

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    Hey all,

    Long time reader, second time poster. While not yet a Tesla owner, I am definitely a long-term Tesla stockholder and am looking forward to some of the great advances TM will be making in the near to mid term (driving a Model X on Mars is definitely long term, but Elon will probably do it).

    Anyway, I have been wondering if an idea I have is even feasible: would it be possible or even make sense to add an additional battery in the frunk to extend range? Such a battery would be designed to take advantage of the available space, a plug-in and mounts would be added to the S (or X) to facilitate quick mounting and dismounting, and the software would be modified to change the suspension settings to handle the additional weight and weight distribution. I'm not thinking of something permanent, but a rentable battery pack to to extend range to 400 or 450 miles for those long drives with people that have large bladder capacity.

    What do you all think? Could it be done and does it make more sense than putting a 5 HP Briggs and Stratton generator up there?

    Cheers,

    Wipster
     
  2. Johan

    Johan Took a TSLA bear test. Came back negative.

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    #2 Johan, Jun 14, 2015
    Last edited: Jun 14, 2015
    Yeah this has been discussed quite a lot (both ideas). None of them make sense, the 5HP motor for obvious reasons (what you gon' do wit it?) and neither does the "extra battery pack". You see, if you put in an extra battery how is that different from having a bigger battery in the first place? Also you gain less and less range as you add batttery weight, and the car would handle poorly, it would be too costly etc. etc. (If not, then Tesla would have made a 400 or 450 mile car to start with, right? That is, if a 400 mile car could be made technically well with regards to size, weight, handling as well as be at an attractive price point for its utility, wouldn't it sell well?).
     
  3. tga

    tga Active Member

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    You'd also need coolant connections and high voltage connections (which would need to be 100% idiot-proof). Much safe and less risky to add more superchargers.

    Plus, the generator would need to be much bigger than 5hp...
     
  4. wipster

    wipster Member

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    Thanks Johan! I figured as much, but I hadn't put the math to it. Obviously the B&S was BS, but you never know until you ask the folks who do know... it would still be fun to try it if you had a spare S around the house... maybe after you get your X, eh?

    Cheers

    Wipster
     
  5. Johan

    Johan Took a TSLA bear test. Came back negative.

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    It would be hella fun, yes.

    Also if you could run a 2 ton car with a Briggs and Stratton 5 hp motor there would be no need for electrification of transport for the foreseable future.
     
  6. Saghost

    Saghost Active Member

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    It is absolutely possible for Tesla to do something like this; it may or may not be possible for a third party to do so. The new dual motor cars even appear to carry suitable High Voltage wiring forward (for the front drive motor inverter.)

    Whether it makes sense is less clear. It you assume it's the same chemistry as the main battery, you'd need another 1300 pounds to double the usable capacity - which likely wouldn't fit in the Frunk (especially on a dual motor car) and would certainly affect performance and handling. Worse, the extra weight will mean worse efficiency - meaning you might not get 500 mile from the double pack.

    A more interesting possibility is an Aluminum-Air battery. This is a primary battery - use it once, then you have to replace the plates and electrolyte. However, they have fantastic energy density. The 1300 Wh/kg demonstrated by current generation batteries mean you can have 85 usable kWh from only 65 kg - about 140 pounds. This sort of battery would easily fit withi minimal impact, and would give you over five hundred miles - once. Better yet, the theoretical limit of the technology it more like 8 kWh/kg - 85 kW in less that 25 pounds.

    Folks who believe in the tech claim that if the waste is recycled you could "recharge" the battery for $1.1/kg - meaning a ~$70 85 kWh replacement (265 miles for $70, $.265 per mile, equivalent to $3.50 gas @ 11 mpg with demonstrated technology - 18 mpg with what they think they'll have soon, and theoretically $12 for 85 kWh, $.045 per mile - 78 mpg at $3.50.)
    Walter
     
  7. wipster

    wipster Member

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    I was actually poking fun at the Chevy Volt style hybrid, even though it does make more sense than the Prius style. The whole idea of a "hybrid" however is dumb to me because of the need to have an ICE (and associated parts) on board, whether to power the car or charge the battery. Now solar panels on the roof? That makes more sense to me.

    Cheers,

    Wipster
     
  8. Johan

    Johan Took a TSLA bear test. Came back negative.

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    Agreed. Hybrids are silly when you think about it, just an interrim solution that will dissappear faster than most people think. I believe most people will ever only own 1 or 0 hybrids in their life, many will go straight from ICE to BEV or have a BEV as their first car in life.

    Regarding solar panels on the roof: Don't even go there. Makes no sense:

    Should Model S have a solar panel?

    (It's a very long thread so just read my synopsis above: Makes no sense)
     
  9. omgwtfbyobbq

    omgwtfbyobbq Member

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    It's difficult but possible in both cases. Besides the substantial engineering required, the extra battery would need exterior mounting points, an interface with the existing system, and a beefier rear suspension. The engine (probably a FPEG) would also require the same, along with a place for a gas tank, fuel pump, and exhaust/emissions system. It's technically feasible if it were incorporated into an EV at the design stage, but it's probably not economically feasible considering the alternatives.
     
  10. Johan

    Johan Took a TSLA bear test. Came back negative.

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    You just "reverse engineered" a hybrid - the type that sell in the millions every year (Toyota Prius/Auris/Corolla for example). I think we're very close to that point where it will just seem silly to keep creating these overly complex solutions.
     
  11. Saghost

    Saghost Active Member

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    Solar energy isn't anywhere near dense enough to be useful driving a big heavy car like the Model S - there's only 1 kW per square meter under optimal conditions at sea level. Current production home solar panels are in the 15-20% efficiency range, so you only get 150-200W per square meter - meaning that the ~20 kW needed for a ~70 mph highway cruise in a modern EV would require 100 square meters of panels on the car (the car isn't 30 feet long, let alone 30 feet wide.)

    However, that 20-30 kW is all you'll ever need in a hybrid with a big battery (and intelligent planning about the battery state of charge and elevation change.) BMW's 650cc range extender would carry a Tesla almost as easily as an i3. A more interesting possibility would be a microturbine. Capstone makes a 30 kW model for the power industry that's about the right size, and I think it could be packaged to fit the Frunk, maybe (packaging size wasn't their top priority.) Of course, then you'd have to come up with fuel tankage somewhere as well.

    It might be more practical to put the range extender into a trailer and bring high voltage DC in using either Supercharger or CHAdeMO protocols, possibly through the existing chargeport (though it'd be much more desirable to create a second port that doesn't hang off of the side of the car.) For that matter, the 20 kW that a dual charger car can accept as 220V AC is enough to cover most driving conditions. Of course, the current software won't allow charging and driving at the same time, but AFAIK there's no physical limitation there - just Tesla trying to keep people from inadvertantly breaking things.
    Walter
     
  12. wipster

    wipster Member

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    #12 wipster, Jun 14, 2015
    Last edited: Jun 14, 2015
    I'll take you at your word, probably not enough space to make a difference. Now making sure the house you build or buy can utilize the power of Ol' Sol, that's a different thing altogether. BTW, while I live on the eastern side of Washington State (the desert side, 300 days of sunshine a year and mostly hydropower), I am of Norwegian descent; my last name is Wiprud (it used to be Viprud, but blame that on Ellis Island. My Great Great Great Grandfather came over in the 1860's and a large part of our family settled in Montana. I applaud the intelligence of my Norwegian brothers and sisters in buying so many Teslas! You probably have more per capita than any nation. Keep buying, I want to see $400/share next year!

    Cheers,

    Wipster
     
  13. Johan

    Johan Took a TSLA bear test. Came back negative.

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    Oh don't worry. We be buyin' over here. But the dollar has gained on us quite a bit lately, which will hurt sales when they adjust prices (and the X comes).
     
  14. wipster

    wipster Member

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    I was kidding about the Briggs... although I wouldn't be surprised to see one in West Virginia or Oklahoma... no offense to anyone living there... LOL!

    - - - Updated - - -

    Yeah, that will be a problem, but on the other hand I have made some killer deals on vinyl here lately, my favorite hobby. Actually bought a couple from Norway!

    Cheers,

    Wipster
     
  15. omgwtfbyobbq

    omgwtfbyobbq Member

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    If you spend 85% of the time driving around without the generator/etc as the EV part, and toss it in when you want to drive the other 15%, I'd say it's an E-REV as opposed to a hybrid. It's what the Volt would have been if it didn't carry around the whole engine/generator/etc 100% of the time. Other examples utilize towable trailers for easy of use.

    How one inventor wants to boost EVs with a towable turbine
     
  16. N4HHE

    N4HHE Member

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    I made my own "hybrid range extender"

    Range_Extender.jpg
     

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