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Are supercharge-limited packs really THAT limited?

Discussion in 'Model S: Battery & Charging' started by malcolm, Apr 2, 2014.

  1. malcolm

    malcolm Active Member

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    #1 malcolm, Apr 2, 2014
    Last edited: Apr 2, 2014
    Excellent blog entry which is well worth a careful read:

    http://teslaowner.wordpress.com/2014/01/01/supercharger-time-test/

    (apologies if this has been covered previously)

    If I understand this correctly, whichever battery pack type you own (A or B) you will only charge at a given Supercharger's maximum rate if you turn up with less than 40% SOC in the pack.

    From zero to 40%, the pack MAY be charged at the Superchargers maximum rate but this will depend on temperature, other cars recharging at the same time etc.

    Once above 40%, all Superchargers start to throttle back, which is why the table in the link shows a range of 43 kWh added in 30 mins from an SC running at 113kW, but only 37 kWh in 30mins from another running at 121kW.

    Given that typical Supercharger use requires a final charge level above 40% (and is highly unlikely to start from empty), the time advantage given by a B pack as opposed to an A is less than you think:

    A quote (attributed to Tesla): “For a customer charging from 20% to 90% (more than enough to go to the next supercharger station), the difference in charging time between an early car and a current car is less than 4 minutes!”

    So I think the rationale for 120kW is to fill more cars in parallel in a reasonable time frame rather than individual cars significantly faster than others.

    Unless B-pack owners would like to list all the things they can manage to do in four minutes :biggrin:

    ETA: At least one person has found that Supercharger etiquette (or lack) has a FAR greater impact on overall delays: http://www.teslamotorsclub.com/showthread.php/29455-Interesting-night-at-the-Supercharger?p=621109&viewfull=1#post621109
     
  2. JohnQ

    JohnQ Active Member

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    I expect you've reviewed the thread Older Teslas limited to 90kW Supercharging. Not much more to add than what's there ... some are upset that it's only 90kW, others that they were pushed to finalize when it was an older battery at 90kW, others that some who received their cars earlier got 120kW capability but they got 90kW (i'm in that situation), and yet others about how the communication of 120kW charging being available was handled.

    Some will dispute the time difference stated by Tesla (rightly, I believe) but I don't think that's the main reason for folks being upset.

    NOTE: not trying to open the can of worms in another thread here.
     
  3. malcolm

    malcolm Active Member

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    #3 malcolm, Apr 2, 2014
    Last edited: Apr 2, 2014
    Thanks for the reminder John.

    I do apologise for reposting the infamous "four minute" line from Tesla as this has been hurtful to a number of Sig owners.

    I guess the only way to settle it will be Supercharger Races - at a TMC Connect event - or the big So Cal thing that's coming up in August.

    Two cars with 85kWh A and B packs with equal starting temperatures and SOCs duel it out to find the time difference for each to charge to 90%.

    As for the communication thing well that does seem to go hand in hand with Tesla's No Advertising position :crying:
     
  4. brianman

    brianman Burrito Founder

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    Or maybe all the B owners that think "the difference doesn't matter, you shouldn't care" should just offer to voluntarily swap packs with A owners that think "it does matter, I do care and you should stop projecting your opinion". That will make the people that care get the battery they want, and the people that don't will have a battery that they will be happy with also. Everybody wins, right?
     
  5. AmpedRealtor

    AmpedRealtor Active Member

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    When were you inconvenienced by your battery type? Or are you just proselytizing based upon rumor, speculation, and the purported experience of others?
     
  6. Kraken

    Kraken Member

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    Thanks to 5.9, we've knocked all of our more recent discussion issues out, so we can revert back to pre-October discussions of A vs B packs and the merits of locals supercharging....

    soon, hopefully tesla will remedy those issues as well
     
  7. JohnQ

    JohnQ Active Member

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    Come, now, surely we can also argue about ... lighted vanity mirrors ... or on board music storage ... or ...
     
  8. tomas

    tomas Traded in 9 rep bars for M3, used to be somebody!

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    The "pre-october" discussions were actually very active into January. In fact, most active thread on this forum. I'm not always with Brianman, but I am totally on this one. The "B" and beyond owners think this is no big deal, but how would they like to have a battery with lesser capability? Even if only a little lesser.

    I find the blog referred by OP to be very theoretical. Time at peak kW may be short, but taper is also much lower for "A"s. The author is largely guessing. It is true, Malcolm, we won't know for sure until there's a "charge off" between two cars that have "A" and "Later" batteries, but are otherwise equivalent.

    Fact is, we will not have resolution of this "soon". The reason the thread on this went relatively quiet is that most of those actively involved got together and communicated off-forum with Tesla, which is the right way to solve a problem. Tesla indicated that they plan to offer a program that will allow owners to upgrade batteries, but not until battery production is less constrained… which could be some time.

    I, for one, was satisfied with that result, because an eventual upgrade of my "A" pack (assuming reasonable economic deal) for a future pack with higher capacity, charging, etc. will make a nice mid-life boost for my car.

    PS: JohnQ, please don't equate this to trivial stuff like vanity mirrors, music storage. Those are desirable features that some people were expecting and want, fair enough. But nobody has them. This is the most critical component of car, and "A" pack owners paid the same price as others whose cars were produced the same week and received a less functional component. That's just not the same. If that's not clear, PM me.

    PPS, I don't blame Tesla, I don't want them to stop improving the car. Ever. I also totally trust them to make good on this. I just don't expect it right away.
     
  9. brianman

    brianman Burrito Founder

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    Every time I charge slower than instantaneous?

    Realistically speaking, it's an inconvenience every time I have to release the fun pedal to stop and juice up. I'm willing to live with it for the other benefits, but it's always an inconvenience. Is it less of an inconvenience than gas? For daily driving, yes. For trip driving, no.
     
  10. malcolm

    malcolm Active Member

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    #10 malcolm, Apr 2, 2014
    Last edited: Apr 2, 2014
    I think one possible elephant in the garage might be upgrading to a higher battery capacity.

    When/if a 110kWh pack becomes available will it be a straight swap that all cars can use (I'm assuming S and X here) or will there be some strange limitation?

    We're all used to cars depreciating in value as soon as we drive them off the lot - but this is more like computers; within a few months functionality changes. ("New low" isn't as low as "Old low" etc).

    No one minds with computers, of course. They don't cost $$$$$.
     
  11. Martini

    Martini Member

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    ...And when a 110Kwh pack upgrade becomes available, it will only work with vins above so-and-so number, and there will be another thread to debate the fairness of this.

    I took my (not Tesla) to the shop the other day. They wanted 190 bucks to update the GPS maps and would only do a firmware update if the car had a demonstrated problem. As for communication, there never has nor will there ever be any. I wish I had Tesla problems to complain about.:smile:
     
  12. rlang59

    rlang59 Member

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    To be fair, that can be said about driving electric in general, even with the superchargers.
     
  13. ViperDoc

    ViperDoc Roadster 1305

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    As a Sig owner who is not upset about the A versus B packs because I believe I received what I was promised, I think that the rear map lights that are currently in the cars and were taken out of the Sigs (and perhaps early production cars) due to concerns about the design with a promise from George Blackenship that they would be retrofit to Model S vehicles built before the redesign are a bigger deal since the retrofit hasn't materialized and was part of the car when I ordered it.
     
  14. ElSupreme

    ElSupreme Model S 03182

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    To be fair, only when you press the juice pedal, and juice up at a Supercharger (without the paired bay occupied) at low state of charge. If you plug in anywhere else it really isn't an inconvenience at all.

    Not saying it isn't an 'inconvenience' but it is only a subset (probably small one) of your total driving.
     
  15. dsm363

    dsm363 Roadster + Sig Model S

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    #15 dsm363, Apr 3, 2014
    Last edited: Apr 3, 2014
    They are back in all cars I thought. I'm actually in the same boat. Do you have early Sig? It appears rear map lights were just left out of some early Sigs. I asked and under warranty was told they can put them in but it requires a new lining and windshield (whole top comes off ). It's not a big deal for me so I may not do it.
     
  16. bluetinc

    bluetinc Member

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    My A pack currently takes just about 1 hour to charge 200 miles, starting at 0. It would be great if one of you would stop by a supercharger and time how long takes you to do the same. Then hang out for Tesla's "4 minutes" and let us know how long it really is.

    I run into this all the time, especially in the winter when charging to 200 miles is even low to hit the next supercharger.

    Peter

     
  17. ElSupreme

    ElSupreme Model S 03182

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    I waited 7 minutes for a chicken biscuit this morning. It honestly isn't all that bad.

    #DarnYouChicFilA
     
  18. Owner

    Owner Active Member

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    Since I am the blog author, I thought I should chime in here. Sorry to not have noticed this thread earlier.

    My supercharger time tests have not been theoretical but based upon empirical data. I've also reported on two more tests here Charger Test 4, 5 QA | Tesla Owner

    And I recently did a road trip to oregon with two more tests.

    In all the tests on my blog, I contacted Tesla directly. With the supercharger situation, they have been excellent to work with since I had empirical data and a preliminary blog post (and I have to admit a reasonable level of traffic on my blog). Tesla actually verified my numbers by looking at their data at the superchargers, and provided the detail responses. Getting a good story on the "normal" tire wear was much much harder until Noe Mejia got involved.

    Don't have anything empirical to add on the different packs. Kind of got lucky in a sense since I sort of intentionally waited for tax reasons to get my car in 2013.

    In my next two tests charging with fully functional superchargers and starting at 0 miles left, I think I achieved 155 miles in 30 minutes. But it was pretty cold (45 degrees) -- okay cold for a Californian. So I have yet to achieve the advertised rate myself. Haven't had time to post this blog yet, will try to do so soon.

     
  19. tomas

    tomas Traded in 9 rep bars for M3, used to be somebody!

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    Thanks for clarifying. Let me do same. I was wrong to call your tests theoretical and I apologize. What I meant to say, and should have been more accurate, is that any extrapolations regarding extra time to charge A pack are theoretical, because the charge curves are quite different. A bunch of people tried to do so and posted on the 90 kW limitation thread, but results and interpretations were all over the place. I think OP is correct that the only decent test would be a charge-off between two cars at same temp etc. from same SOC to same SOC. Then, I'm sure the supercharger on one would stop mid-charge… DRAT.

    Anyway, I believe it is nit picking anyway. It's a little longer. Not enough to warrant getting super agitated or expect Tesla to replace at 40k a pop. Enough to want an upgrade program, as they're planning.
     
  20. brianman

    brianman Burrito Founder

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    (1) Some would say computers depreciate faster.
    (2) Some would disagree with this as well.

    Regarding #2... I've spend more on almost every computer I've bought in the last decade than Doug_G did on his track Sentra or whatever it was.
     

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