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Whitestar info soon ?

Discussion in 'Model S' started by Cobos, Jan 29, 2008.

  1. Cobos

    Cobos S60 owner since 2013

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    Thought I might mention that in the 35th comment on the latest Feel blog (Web2.0 vs Dead trees) in a comment made by Dirk the editor mentions that they will release more Whitestar info soon. Their definition of soon might not match mine, but I figure the Town Hall meeting on Thursday would be a good bet?

    Cobos
     
  2. Kardax

    Kardax Member

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    My stance on WhiteStar today is the same as before... Tesla should keep quiet about it until Roadster deliveries have started.

    The reason: 600 people patiently (or otherwise) still waiting for their cars. Anything that makes Tesla look like it's distracted would make their paying customers very upset.

    Tesla has nothing to gain by revealing WhiteStar details now.

    -Ryan
     
  3. malcolm

    malcolm Active Member

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    #3 malcolm, Jan 30, 2008
    Last edited: Jan 30, 2008
    I'm not so sure.

    As the recent DriveTrain shuffle proves - Elon is very smart and chooses to set tough technical challenges for the political benefits they bring. An announcement on Whitestar specs and styling ideas at this stage is going to be a copy of a presentation to possible auto partners and investors, not customers.

    It is likely that it won't push envelops and preconceptions as the Roadster did since it is all about attracting an un-innovative but affluent auto partner.

    But how on earth is Elon going to manage to stop himself from losing his patience with such a company?
     
  4. vfx

    vfx Well-Known Member

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    An ambitious group are they? Not only are they building the Whitestar and the Bluestar but the Whitestar is to have TWO drivetrains!

    All while tweeking the Roadster to work properly.
     
  5. Kardax

    Kardax Member

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    The Roadster is very nearly finished, it's mostly a matter of supply chain management now. This frees up the engineers to work on future projects.

    -Ryan
     
  6. malcolm

    malcolm Active Member

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    Thing that's puzzling me is how you recharge a battery pack while you continue to draw power from it, without affecting calender life and while maintaining reasonable performance.

    Maybe you don't and just do what GM propose to do with the Volt - after the all-electric range is exhausted the generator kicks in but doesn't recharge the battery, simply stops it getting flatter.
     
  7. TEG

    TEG TMC Moderator

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    It is all just power moving around. If you have a little tiny ICE generator running all the time you could draw 1/4 power from the generator and 3/4 power from the batteries. In other words the generator power could go right to the eMotor. You don't have to charge one side of the batteries and draw from the other.

    The problem is the marketing angle of saying it is a "REEV". If you expect people to think of it as a 40 mile range EV with an "emergency range extender" never to be used except when you accidentally run the batteries down that is one thing. But I think in the real world you would prefer to have the ICE running sooner to keep the pack from getting all the way run down so frequently.
    If you start up the ICE earlier and more frequently people may be more inclined to call it a hybrid instead of an EV with range extender. Marketing and engineering need to work together to work out all the details.
     
  8. Kardax

    Kardax Member

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    I would think that running the pack down frequently is the whole point of any PHEV. Otherwise, why bother with the plug-in part?

    -Ryan
     
  9. TEG

    TEG TMC Moderator

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    #9 TEG, Feb 3, 2008
    Last edited: Feb 4, 2008
    Well, depending on how they engineer the thing you may have reduced performance when the battery pack is run down. For instance note how the Fisker plans to have a paddle on the steering wheel to switch from "Stealth" mode to "Sport" mode which will fire up the ICE to add some more power to get the eMotor up to full output (apparently the battery pack is inadequate by itself). If you have an ICE big enough to fully power the vehicle then you are carrying a lot of weight around.

    If you are willing to fire up the ICE more frequently then you can consider some benefits:

    #1: Battery pack doesn't have to offer as much max power output because you can supplement from the ICE/generator when requested.
    #2: The ICE doesn't necessarily have to be as big because you run it while the batteries can help so you get a power blend for a longer range than you would get from the pack alone. Eventually the pack will still run down so you would end up in a low power "limp" mode if the ICE/generator was too small to keep the pack from getting fully discharged.
    #3: You can drain the batteries more slowly if the ICE/generator is helping so you may be able to get through the month with less range of pack cycling which could help the batteries last longer in the long term.

    Imagine you had a weight & price target, and you could take two approaches.

    Approach #1:
    40 mile battery pack + 70HP ICE generator
    The vehicles runs on 100% battery until near empty then the ICE kicks in until you get to a plug. (Trying to be like an EV but with an emergency generator that maintains close to full performance on fuel alone when the pack is spent)

    Approach #2:
    80 mile battery pack + 20HP ICE generator
    The vehicle starts up the ICE much sooner. You could go perhaps 250 miles on "blended power" (extended 80 mile pack + ICE assist) before you run the battery pack down and experience reduced performance (limping to a plug)

    Approach #1 would be better if what you wanted was < 40 mile daily commute and never start the ICE. Also if you had a pack that could stand up to daily full discharge / recharge.

    Approach #2 would be better if you routinely drove more than 40 miles but less than 250 miles before plugging in. You could do a fairly long commute without ever running the pack all the way down which would likely give the battery pack a longer lifespan.

    I hope you can see what I mean - driving habits and plug-in habits could dictate different designs.

    If you are willing to use "blended power" (ICE generator + some pack capacity) together then there are a lot more options as to how you size and configure things.
     
  10. Kardax

    Kardax Member

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    I understand what you're saying, but I don't agree with some of your fundamentals...

    Firstly, the only type of battery I can think of that has power output issues would be a small number of conventional lithium-ion cells. Get a large number of them (like in the Tesla Roadster), and you have all the power you need. There are also chemistries that trade energy density for power density... A123 and AltairNano (and likely others I'm not thinking of) can totally discharge in 10 minutes, then recharge in another 10, thousands of times without any substantial wear. Tesla has already indicated they're using a differenct chemistry for the PHEV version of WhiteStar, and my bet it's along the lines of the above...

    Given that power output doesn't have to be a problem, your gas engine only needs to be big enough to sustain highway speed, plus a little extra to charge the battery. The battery would be used for bursts of energy when hard acceleration is needed. I don't think 20HP is enough, but 70HP is probably more than necessary.

    If the engine is sized correctly, the only issue the customer would then need to consider is how much electric range they're willing to pay for. People who live close to work might go with 40 miles, longer distance people would go for 80.

    The other thing is that battery lifespan isn't as important for PHEVs. If you get an 80 mile pack that's down to 60 after five years... you might not be affected at all. The worst case is that your engine will fire up sooner on a long trip, maybe costing you another $5 in gas.

    -Ryan
     
  11. Cobos

    Cobos S60 owner since 2013

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    I think this is actually a big point. People (people as in Joe public) probably wont see this themselves until they've had the car for a few years. But when you've got a range extender unless you drive exactly the same route every day for like 10 years you wouldn't notice as for every month after a certain period the RE starts up another 100 yards closer to your house... It's the same thing that happens to ICE cars now, they get crappier and crappier mileage as they age and as you put mileage on your oil change f. inst.

    Cobos
     
  12. vfx

    vfx Well-Known Member

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    What about the readout? There are many Prius drivers that slavenly look the numbers and adjust their driving for max mpg. The battery loss AND the ICE degradation will surely be noted.
     
  13. Cobos

    Cobos S60 owner since 2013

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    Readouts.... I remember the time when we had a odometer, a speedometer and a fuel gauge and we were happy. Oh wait...that is what my car got :) As I'm driving around in such an old car I tend to forget the newer cars has a lot better instrumentation than my old trusty one. I suppose that will show everyone what the status on the battery is...

    Cobos
     
  14. TEG

    TEG TMC Moderator

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    So, why does Fisker require you to start the ICE to get full power output from the eMotor?

    Tesla is talking about Whitestar having even more eMotor power than the Roadster, yet they are talking about a REEV version with a much smaller (and less expensive) battery pack. I do think that battery power output capability could be an issue here.

    Tesla is trying to use inexpensive commodity laptop cells (in large quantities). Sure you could get expensive cells with higher "power density", but they are trying to find solutions that use more "run of the mill" batteries.

    I don't think my idea of running the ICE while the pack still has a lot of charge left is unfounded. I think we might see more applications designed to work that way. Letting the pack run to near empty before starting the ICE sounds good from a marketing standpoint, and works in an "ideal world" situation where people don't ever drive more than 40 miles between plugs, but I don't think that will work for everyone.

    Does the mainstream want a "mock EV" that lugs around a big ICE generator for those days when you go over your BEV limit, or do they want a well engineered Hybrid that does use some gas, but with significant battery assist, and plug in capability they get effectively over 100 MPG?
    I guess we will see which wins... The series PHEV Volt or the next gen PHEV Prius. If people only ever drive short distances, and always plug in long enough then the Volt may be the winner. If people do drive more than 40 miles frequently, or neglect to plug in sometimes then the Prius approach may end up with the higher effective MPG numbers.
     
  15. AGR

    AGR Member

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    A mid size family sedan with all the technolgy and safety features that customers expect with usually an aluminum ICE weighs over 3,000 lbs. with a carrying capacity of lets say 1,500 lbs for a GVM of 4,500 lbs.

    This same mis size sedan fully electric would easely weigh an additional 1,000 lbs to accomodate the weight of a battery pack for a reasonable range for a GVW of 5,500 lbs which is getting into large sedan or pick up territory.

    The Tesla Roadster starts out as a small very light ICE powered Elise, and turns into a very heavy Tesla Roadster(compared to the Elise). Putting an addtional 1,000 lbs (batteries) in a Camry would create several challenges.

    The compromise is a battery pack and a small range extender.

    TEG, has described a few scenarios of how it could work.

    Also keeping in mind that most elctronics in modern cars have a genuine distaste for voltage fluctuations, they love to run on the alternator at 13.5 volts.
     
  16. mt2

    mt2 Member

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    TEG, you make a very good point. Elsewhere, we discussed what happens to an engine and it's gas if you only run it once or twice a year.

    I think my ideal situation would be an engine that produces only as much as or less than the power needed to sustain the vehicle at highway speeds. Suppose, for instance, that the genset kicks in when the battery is at 60% capacity. The battery would continue to drain if I was doing highway driving, but the range for the remaining 60% could be nearly indefinite depending on how I drive. Assuming I have to get off the highway once in a while to eat and use the restroom, regen would help extend the range further.

    In that type of scenario, it would be possible to run the batteries to empty - especially as they age. But that would be really rare and a driver would have a lot more time to find a place to charge up. If I could get 400 to 500 miles before the batteries are drained, I could plan my road trips around that.
     
  17. mt2

    mt2 Member

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    Oh, by the way, that would truly make the vehicle a Range Extended Electric Vehicle. I would expect a series hybrid to continue to run as long as there is gas in it. But a REEV doesn't get indefinite range; it just gets extended range.
     
  18. Kardax

    Kardax Member

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    Everything Fisker says is subject to change. They don't even have a driveable prototype yet.

    All of your statements about firing up the ICE before battery depletion assume a low-power battery (commodity laptop cells in particular). These cannot survive the heavy cycling of a PHEV usage profile. They can't be used in WhiteStar. Tesla must use a high-power, high-durability design like A123 or AltairNano (although it may not come from either of those companies).

    Since Tesla must go with such a battery design, there is no need to run the ICE except when the battery is critically low.

    It's going to come down to three factors: cost, range, and gasoline availability. The company that delivers the best balance of cost and range will be at an advantage. Any threat of a gasoline shortage will tip the balance in favor of range. A vehicle that has excellent performance (as WhiteStar is apparently pursuing) can justify a higher price, too.

    -Ryan
     
  19. stopcrazypp

    stopcrazypp Well-Known Member

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    For comparisons sake, in 100k miles (the proposed warranty on the battery) the Volt would fully charge 1750 times (since it lasts 40 miles until it reaches 30% charge). This would be true if the generator always went through the battery and you travelled the 40 miles in EV and the rest with the generator. This would also be true if you travelled exclusively on the battery regardless of the generator. So to allow the possibility of people who would travel exclusively on the battery, the battery will HAVE to last 1750 charges regardless if the generator bypassed the motor. So I guess you are right, Kardax, it doesn't really matter so much to the manufacturer whether the charge can go directly to the motor since the battery will need to last that long anyways.

    However, if you were a person who travels more than 140 miles before you can charge, then the pack would only need to last 500 charges (typical commodity battery life) to last 100k miles, if the system can bypass the battery (an extension of this is that you can make an EV on commodity li-ion cells last 100k miles if the pack can travel 140 miles from full to completely drained). It is easy to see the implementation has a huge impact on battery life, but since the current cells supposedly last 7000 charges, it seems to make the argument moot.

    I wonder what the advantages in performance each configuration will have. If the generator went directly to the motor with no battery assist, you would need a pretty strong generator to provide some decent performance, so I guess that would not be optimal. What I still don't know is if the performance will be better if the generator went exclusively through the battery (what you are proposing is the better solution) or if there was a mix (what TEG is proposing).

    BTW the Volt was originally designed to fire the ICE up at 30% (don't know if they changed it though), so it's incorrect to say "there is no need to run the ICE except when the battery is critically low." I think if they want to keep decent performance and not just highway cruising, they will need to fire early and have a buffer regardless of how power dense the battery is (as you also can run into the problem of the charge depleting more quickly than you are charging the battery if there is no buffer). Though I'm not sure if the decision is based on preserving battery life (as it's bad to run li-ion fully down) or to preserve performance. I mean, since they have a generator on board anyway, it would be stupid to let the battery run down to critical levels and engage limp mode when you can fire it up early and prevent any negative effect on performance.
     
  20. TEG

    TEG TMC Moderator

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    Some of the talk about "charge to 80%" and "draw to 30%" could be based on the idea that battery life is substantially shortened if you try to push it to the limits. As Tesla mentioned, they plan to offer the option of a "less than totally full" recharge to help save the battery life. When Volt says they plan to fire the ICE at 30% they may mean that they have to do that to get expected battery lifespan. That lower 30% may be intended to never be used unless it was a dire emergency (such as you ran out of gasoline too).

    Because of this there could be some "numbers games" played.
    Someone could publish range numbers based on situations where you are "abusing" the batteries. In practice, most batteries don't like to be cycled between 0% and 100%. The Prius batteries are kept in a "happy range" to avoid early failure as well.

    So, the firmware to control ICE behavior isn't just designed to maximize BEV only range, or improve performance, but it also needs to be designed to protect the batteries within some limits.

    --------------------------------------

    The whole REEV thing brings up some debate... What qualifies to be called a REEV?

    Is it just if the motive force is 100% electric motor? So what if you just take a Ford F150, and replace the transmission with a DC generator hooked directly to a DC motor. Then it is a 100% electric motor driven vehicle (although 100% powered by an ICE generator). I assume that this would not be called a REEV. But what if you put in a very small buffer battery that could give you 1 mile of electric motion with the ICE turned off. Would that be a REEV? I suppose so.

    Customers are going to have to research their PHEVs to find what suits their driving habits.

    Do you want a vehicle with a 10 mile battery pack, and large ICE?
    How about a 40 mile battery pack and medium sized ICE?
    How about an 120 mile battery pack with a very small ICE?
     

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