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Does the current refreshed 90D have secret capacity up to a 100D?

Discussion in 'Model S: Battery & Charging' started by Advicebox, Aug 16, 2016.

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Will the refreshed Model S 90 have a software upgrade to 100 in the future?

  1. Yes

    12 vote(s)
    29.3%
  2. No

    29 vote(s)
    70.7%
  1. Advicebox

    Advicebox Member

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    I'm sure it's anyone's guess, but does anyone want to speculate or share rumors they are hearing? It would be great to think this is a possibility.
     
  2. csanders90D

    csanders90D Member

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    It's not a 100, you can tell from supercharging speed. My refreshed 90D was barely at a trickle when I got back to the SC and it was at 98%. If it were really a 100 it would have still been charging faster.
     
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  3. Advicebox

    Advicebox Member

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    Actually I talked to a Tesla rep managing one of the Supercharger locations. He confirmed that the charge rate is throttled by Tesla based on how much you need to discourage folks from topping off. According to the rep, if you only need 50 miles the car will charge super slowly, where as the rate for folks showing up needing hundreds of miles will charge almost up to the max 370 miles per hour. So not sure that's a good indicator, plus if Tesla can software limit the battery, they could also easily simulate a 90 kWh battery even if physically 100 kWh was in there.

    Not saying you are wrong, it's anyone's guess, just not sure of the reasoning.
     
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  4. commasign

    commasign Active Member

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    Only a few times (e.g. triple under body shield, autopilot, and post-refresh 75kWh battery) has Tesla made a major hardware change in currently shipping or in-production cars and not make a formal announcement about it right away. Even in those cases, the formal announcement was within a few weeks. So it's definitely possible the 90kWh cars coming off the line right now are actually software locked 100kWh batteries. But the probability decreases rapidly as you go back even a few weeks in production.
     
  5. gaswalla

    gaswalla P4201/85/airsusp/pano/19i

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    It's not a 100.. For sure.
    The supercharger rate is a good example.
    The proof is from the folks that measured voltage at 100 percent on old 90s vs brand new 90s.... It's the same voltage - hence both cars are at the same state of charge (ie - not that one is at 90 percent)
    Folks who won't let their wishful thinking rest, are really just going through the stages of grief...currently in denial
     
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  6. Advicebox

    Advicebox Member

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    So last bit of wishful thinking.. but any chance the 90 old and new have the potential for 100?

    and LOL to the stages of grief.. been in bliss for two months after taking delivery, just starting to think about things like this.
     
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  7. Btrflyl8e

    Btrflyl8e Active Member

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    Back in 2013, they also secretly produced the 60 with the heavier duty wiring to support supercharging, even if not ordered with that capability. I was one of the folks who ordered without, so lucked out. It was announced in a tweet by Elon.
     
  8. wdolson

    wdolson Active Member

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    How does Tesla know how far you are going and how much charge you need to get there? You may have misunderstood what the rep was telling you.

    It isn't Tesla knowing anything about how far your going that is the factor, it's how close to full the battery is. When a li-ion battery is at a very low state of charge, it can be charged at maximum charging current without damage. However, when the battery nears full charge, the charging current needs to taper down or the battery will be damaged.

    One thing that has been found in the field is the post -refresh 90 battery packs do supercharge charge differently than earlier packs and nobody knows if it's software or some other difference. They don't charge as fast as the old batteries when at a very low state of charge, but when at a middling charge they charge much faster than the old batteries.

    Um, voltage isn't what you want to look at. A Watt is Voltage times Current. Batteries are rated at a nominal voltage and a maximum voltage, and then an amp-hour rating. Hence battery packs are rated in KWh. The voltage of a battery is determined by the materials that make up the anode and the cathode. Combinations of different materials produce different voltages.

    Lithium has an electrode potential of -3.026 and is the active ingredient in lithium ion cells. Tesla uses a cahode made of cobaltic oxide (mixed with nickel and aluminum). Cobalt oxide's electrode potential is +1.42. That yields a maximum of 4.446V potential, but the other materials plus various conditions does not make that achievable in the real world. The actual chemistry of Li-ion cells extremely complex with dozens of variables. In fact only about 2% of a li-ion battery is lithium and the Tesla cells are about 9% cobalt. The lithium at the anode is held in a graphite (carbon) matrix.

    The batteries in the 90 KWh packs mix in some silicon compounds with the graphite because the silicon allows more energy to be released by the reaction. Replacing the graphite with silicon would allow the battery to store more energy (higher amp-hour), but it doesn't change the voltage at all, but silicon has a major draw back. When it absorbs lithium ions, it expands and if there is more than a tiny amount in the battery, a strain is put on the battery case every time you charge the battery and it will fail after a few charges.

    Labs all over the world are experimenting with slews of different materials to increase the amp-hour capacity of li-ion batteries with new materials that can be added to the graphite matrix. What goes on in there is so vastly complex that nobody fully understands it. New improvements are found all the time with tiny amounts of different materials. The ratios are so touchy that adding 0.1% of some material may help a lot, but adding 0.2% will destroy the battery in a few charges.

    This page details the common types of li-ion batteries in use today:
    Types of Lithium-ion Batteries – Battery University

    The NCA type cell used by Tesla is just one of several different types of li-ion batteries in use, each with different pros and cons.

    So two different versions of battery packs having the same voltage when charged isn't indicative of anything.

    I would like to believe that the 90s being built since the refresh are really 100s (since my car is only 2 months old), but I would say that's very unlikely. Telsa has done some odd things before, so I wouldn't rule it out, but I don't see why they would keep it a secret this long if it was happening.
     
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  9. emir-t

    emir-t Member

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    Great informative post! Here are some possibilities I'm thinking about since making the newer batteries taper off later whilst Supercharging is an important development IMHO

    1) They were always too cautios with tapering in the Supercharger algorithm. After 3 years of testing they decided they could allow the cells to taper off later. Updated it so now 90D is better with Supercharging. (Then why didn't it happen with other models?)

    2) The new cells, as you've mentioned, have silicon in the anode. They weren't exactly sure on how much this new material would get affected, so they lay low on Supercharging taper. After enough data with enough silicon packs on the road, they decided there was no harm done so they updated it. (I think this is the most likely one, new 90D packs were slower to Supercharger even than the old 85 packs. I remember a video Bjorn's)

    3) Later versions of the facelift 90D are actually software limited 100D that we keep seeing listed. So the supercharge can taper off later because of higher capacity. (My wish would be on this one, that would mean they sucessfully aded even more silicon in the anode, resulting in a 17% more energy dense chemistry over the course of 3 years. Same chemistry with 21-70 yields even more potential then)

    We'll see I guess. We're living in fun times.
     
  10. NikeWings

    NikeWings Member

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    I said "self, I know this is wishful thinking but i'm voting yes anyway" click.
     
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  11. Electric700

    Electric700 Member

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    You have posted this information in other threads, but it's misleading. As another member posted, the throttling is not occurring to discourage a behavior but rather is a function of how the batteries were designed, to help keep them functioning normally. There is a separate issue that has come up within the last few weeks where the Supercharging rate unexpectedly drops for some people (e.g. 80 A and 300 V with the battery at 15%, where the current should be closer to 300 A), but Tesla is aware of the problem and is working on a solution.

    Now you know and can tell the person who told you :) [email protected] is another way to reach out to them, so you can give them the name/location of the attendant since that person's information really should be updated.
     
  12. richrootes

    richrootes Member

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    If someone has had a recent delivery of a 90, can't they simply check the battery label in the right hand wheelwell to confirm/refute this?
     
  13. rhumbliner

    rhumbliner Member

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    As @Electric700 pointed out, you're referring to the San Mateo SC. Your Tesla rep is a Tesla employee but he's hardly a Tesla "rep" and he hardly "manages" the SC location. I'd be careful about putting forth conspiracy theories when other explanations are so much simpler and more believable.
     
  14. ion

    ion Member

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    My recently delivered MX-90D (late June 2016) does not limit the battery power at low state of charge. On my old S85D when I get below 50 miles rated range left an orange dashed line limits power output when I floor it. On the recent 90 D MX there is no such power limit. Leads me to believe there is still lots of battery capacity left when the remaining range shows 50 miles. Would indicate that the battery is larger than 90 kWhrs and is software limited.
     
  15. ion

    ion Member

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    This would not mean too much ; if they software unlock the extra 10 kWhrs, you will likely get a new sticker and badge for the trunk
     
  16. wdolson

    wdolson Active Member

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    If they were hiding it for some reason they would continue using 90 stickers on the battery pack until the announcement, though the pack would probably be a new revision.

    My car was built around Memorial Day weekend and it says 90 KWh, 400V, with a part number of 1056776-00-E.

    Does anyone have a rev letter newer than E?

    It's possible the battery has extra capacity, but it's also quite possible they changed something else and its the same battery cells. Tesla is always tinkering with the hardware and software, so it would be impossible to tell without a lot of test equipment.

    I don't think anybody has torn down a battery pack since wk057 did the older 85 KWh pack. I can't find any confirmation that the 90 KWh pack even has the same number of cells as the old pack, though I have no reason to suspect otherwise. The 75 KWh pack could have more cells than the old 60 and 70 packs, but nobody has torn apart any of the newer "small" packs to confirm.

    I did do some calculations on battery cells and posted my numbers here:
    Tesla Battery Generations

    We know the 1st generation cells were 3.1 Ah batteries. I'm assuming the original 70 and 90 pack have the same cells which works pretty close if the new cells are rated at 3.5 Ah, using the same number of cells for the small and large pack as were used in the 60 and 85 KWh packs. wk057 confirmed that Tesla was lying somewhat about the rating of the 85 pack. It really only had 81.48 KWh of capacity, though the original 60 was slightly over 60 KWh.

    Using 3.5 Ah for the second generation batteries, the 70 pack comes out to 69.6 KWh and the 90 comes out to 91.997 KWh. That's close enough I think the old 70 pack had the same number of cells as the old 60 and it was using the same cells as the 90.

    Now I ran some speculative numbers on a 3rd generation cell and if the packs keep the same number of cells and assume 3.9 Ah cells, you get pack sizes of 77.58 KWh and 102,5 KWh. If the new 75 pack (which is software limited to 60 in the new 60 KWh) is using the same number of cells as the older small packs, then it would have to be using a 3rd generation cell. Tesla could also bump the 70 pack to 75 by adding cells to each module.

    Tesla groups 6 cells in series, then puts X number of them in parallel in a module. Then they put the modules in series. The old small pack was confirmed with 64 X 6 cell per module with 14 modules total. The large pack was 74 X 6 cell per module with 16 modules total.

    By putting 68 X 6 cells per module and still using 14 modules, with the second generation cells, Tesla could make a 73. 97 KWh pack. Using 69 in parallel instead of 68 would bring the capacity to 75.1 KWh. So it's very possible the 75 KWh pack is the same cell with just more cells per module. By adding cells per module in parallel, it would not change the voltage of the pack at all, just the current capacity.

    Someone would have to tear open a new 75 pack to verify.

    If the new 75 pack was using a 3rd generation cell, they may have only been using them in the 75s initially because of a short term supply limitation. Though I would think the supply would be improving by now.
     
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