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  1. F

    200 kWh Roadster Pack: How is Tesla Pulling This Off?

    The difference is the gas/fire vent path (safety) Double stack can be made to work but blade config is safer
  2. F

    200 kWh Roadster Pack: How is Tesla Pulling This Off?

    The pack is not a double stack. The modules are mounted on their side in a blade config...
  3. F

    Tesla Product Announcement at noon

    More cells in parallel means lower resistance. Not using thin aluminum bond wire fusible links means lower resistance. Lower resistance means increased efficiency. This is the new Model 3 pack architecture "prototype" pack but the gigafactory cells are made for cooling on one end and both pos...
  4. F

    Tesla's response to me leaking info about the P100D?

    Yeah wk is actually doing Tesla a favor here. It is scaring the firmware/software team into action and going forward they will be much more careful. Elon is giving a wink & nod that what happened here is borderline OK, but that doesn't mean the firmware/software team see's it that way. From...
  5. F

    Tesla's response to me leaking info about the P100D?

    hacking any computer you have physical access to is rather trivial. I would be impressed if wk could pull of a remote hack. we actually need white hats working on remote hacks. The 100 pack is an open secret for anyone living in the Bay Area that knows a couple Tesla engineers. This is not top...
  6. F

    Tesla's 85 kWh rating needs an asterisk (up to 81 kWh, with up to ~77 kWh usable)

    nope Apple destroyed Mission. They lost one team member to Apple which didn't appear to be a big deal at first, but just as they were about to lock in funding to ramp production Apple poached the rest of the core team. The trick was the first person they recruited knew everyone's salary at...
  7. F

    Tesla's 85 kWh rating needs an asterisk (up to 81 kWh, with up to ~77 kWh usable)

    the two ends of a 18650 cell are 12X more conductive than the side (think direct-er connection to jelly roll) if you heat/cool on only one end thru a base plate (with terminals on the other) only you are still doing 6X better than a full cooling jacket wrap around the entire circumference of...
  8. F

    Tesla's 85 kWh rating needs an asterisk (up to 81 kWh, with up to ~77 kWh usable)

    I see what you mean and I apologize for misunderstanding. Yes face value has recently been updated, not sure if it is because of us or because legally if you advertise 7 that means 6.5-7.0+ 6.4 must be advertised as 6 or 6.4, but the data sheet has always stated 6.4 since launch
  9. F

    Tesla's 85 kWh rating needs an asterisk (up to 81 kWh, with up to ~77 kWh usable)

    you think wrong. tesla has always stated 6.4 usable at 25C stationary storage always states usable capacity going back to the days of lead and iron and sodium
  10. F

    Tesla's 85 kWh rating needs an asterisk (up to 81 kWh, with up to ~77 kWh usable)

    ask yourself why Roadsters have been bricked with NCA cells? all lithium cells self discharge. it dependes on temp and age. accept it
  11. F

    Tesla's 85 kWh rating needs an asterisk (up to 81 kWh, with up to ~77 kWh usable)

    all lithiums cells self discharge with zero load. if you figure the reserve is roughly 5% of the pack and you know the self discharge can vary between .25-3% month dependeding on the age and temp of cell and whether the BMB is still active best case it could be around a year. worst case it...
  12. F

    Tesla's 85 kWh rating needs an asterisk (up to 81 kWh, with up to ~77 kWh usable)

    the car is not bricked by the BMS when you hit the reserve. Bricking a car means you have discharged the cells so low that they are damaged and not safe to recharge. this was definitely possible on a roadster but no one knows for sure if the same is true with the model s cells as they may use...
  13. F

    Tesla's 85 kWh rating needs an asterisk (up to 81 kWh, with up to ~77 kWh usable)

    the car will switch into a ultra low power mode (everything off but the bmb's and they even go down and cells continue to self discharge) and you can drain it to zero. the reserve capacity is technically usable capacity in storage, just not while driving. try driving to zero miles and park your...
  14. F

    Tesla's 85 kWh rating needs an asterisk (up to 81 kWh, with up to ~77 kWh usable)

    yeah too bad the only global standard is to state the spec capacity. you could mandate all cars state the usable capacity at 65mph (since usable capacity is speed dependent for more reasons than one) but wouldnt it be simpler to state the range at 65mph and then have customers use that value...
  15. F

    Tesla's 85 kWh rating needs an asterisk (up to 81 kWh, with up to ~77 kWh usable)

    no. for all the reasons I already listed and because the reserve capacity (aka brick protection) is a larger percentage of a smaller pack in any case Tesla's ONLY obligation is to spec the pack capacity at or below the capacity based on the cell spec given it is spec'd 85 not 85.0 the pack...
  16. F

    Tesla's 85 kWh rating needs an asterisk (up to 81 kWh, with up to ~77 kWh usable)

    Do you know what a hypothetical example is? Fine replace 155 flat out with "155 until the speed is limited and then continue to hold down the accel until you run out of juice" and the same is true. anyone even remotely familar with lithium cells knows the capacity is inversely proportional to...
  17. F

    Tesla's 85 kWh rating needs an asterisk (up to 81 kWh, with up to ~77 kWh usable)

    You are still not getting it.... 81kwh ESTIMATE reported by the BMS is based on driving the car. if you simply parked the car and left the stereo on (or turned the car off because it is really always on) the battery pack would deliver more than 81kwh the amount of Wh a cell delivers is...
  18. F

    Tesla's 85 kWh rating needs an asterisk (up to 81 kWh, with up to ~77 kWh usable)

    This is the most sadly comical quote from the expert: "The car's BMS also reports the usable capacity as around 76.5 kWh with a 4 kWh buffer on my own car. See my CAN deciphering document for my CAN deciphering document which includes how to decode this data. The fact that the car reports these...
  19. F

    Tesla's 85 kWh rating needs an asterisk (up to 81 kWh, with up to ~77 kWh usable)

    Let's see how well real experts from The Electrochemical Society do compared to the "expert" here. They measure two NCA cells (Panasonic NCR18650A and Panasonic NCR18650B) "A testing methodology consisting of six stages of testing was proposedand conducted on five commercially available Li-ion...
  20. F

    Tesla's 85 kWh rating needs an asterisk (up to 81 kWh, with up to ~77 kWh usable)

    48.5g is the max weight. The typical weight is 47.5g. In any case the Model S pack is not a 18650B...
  21. F

    Tesla's 85 kWh rating needs an asterisk (up to 81 kWh, with up to ~77 kWh usable)

    On top of that note their inconsistent methodology: "I always like to run through three to five discharge cycles before using the data from the discharge curve for analysis. " Which is it 3 or 5? That can make a huge difference with an NCA cell. Also note the claimed BE spec sheet pictured...
  22. F

    Tesla's 85 kWh rating needs an asterisk (up to 81 kWh, with up to ~77 kWh usable)

    Thanks bud. I will calm down a bit. As an EE with a metrology background and over 20 years of experience working with EV's the one thing I can tell you is the smartest scientists (excepting physicists) and engineers are usually the worst at making accurate/precise measurements. The other point...
  23. F

    Tesla's 85 kWh rating needs an asterisk (up to 81 kWh, with up to ~77 kWh usable)

    Yes I do not trust the self proclaimed battery expert who has not shared much details about his instrumentation or methods used to test individual cells before thrashing Tesla let alone raw data now all over the internet we have headlines such as "battery expert shows blah blah blah" Here is a...
  24. F

    Tesla's 85 kWh rating needs an asterisk (up to 81 kWh, with up to ~77 kWh usable)

    From your first post: Tapping out? One "word": lol. Maybe next time you should keep your "conclusions" to yourself given their implications.... ¯\_(ツ)_/¯
  25. F

    Tesla's 85 kWh rating needs an asterisk (up to 81 kWh, with up to ~77 kWh usable)

    Tesla is NOT "pre-cycling" their cells. They are QC'd at Panasonic with one cycle (battery of measurements) and then a quick self-discharge test, and then QC'd at Tesla once with once cycle (battery of measurement) and then a longer term self-discharge test. If Panasonic was SAFT all the...
  26. F

    Tesla's 85 kWh rating needs an asterisk (up to 81 kWh, with up to ~77 kWh usable)

    There is a difference between being "honest" and stupid. When everyone is forced to state the usable capacity based on some technical standard only then will Tesla do it.
  27. F

    Tesla's 85 kWh rating needs an asterisk (up to 81 kWh, with up to ~77 kWh usable)

    I am fully aware of the fact the powerwall uses NMC cells. What you fail to note is the 7kwh pack measures closer to double that new. The reserve can be changed with time so they can honor the 10 year warranty. you can imagine when u bolt a battery to a wood wall safety wins out over energy...
  28. F

    Tesla's 85 kWh rating needs an asterisk (up to 81 kWh, with up to ~77 kWh usable)

    Again you have a noble purpose and it is good to share information, but to suggest Tesla has some sort of nefarious intent with regards to any of their specs is plain WRONG and I will call you out on it everytime. Why not start a new thread and focus on the data this time.
  29. F

    Tesla's 85 kWh rating needs an asterisk (up to 81 kWh, with up to ~77 kWh usable)

    Yes to clarify: in the first quote I was reference "calendar aging". In the second quote I was referencing what happens as the cells "age" (in general which includes cycle aging and calendar aging and everything else) I had it right the first time but if you are being pedantic... Again you...
  30. F

    Tesla's 85 kWh rating needs an asterisk (up to 81 kWh, with up to ~77 kWh usable)

    Which supports what I just wrote a minute ago: "In time you will see that the NCA cells are bested suited for EV use as the calendar aging almost stops at one point and then aging is dependent on how they are used" ¯\_(ツ)_/¯
  31. F

    Tesla's 85 kWh rating needs an asterisk (up to 81 kWh, with up to ~77 kWh usable)

    The cells are already months old and used (aka thoroughly tested) before they are built into a pack. And even then with your Model you will notice range degrades more rapidly and then starts levels out (never truly levels out). Tesla also has the ability to change the the usable pack capacity...
  32. F

    Tesla's 85 kWh rating needs an asterisk (up to 81 kWh, with up to ~77 kWh usable)

    No it would be more than once if they were brand new, but yes NCA cells rapidly degrade at first whether cycled or not. Again this is industry standard practice to rate a battery pack based on the cell spec. In time you will see that the NCA cells are bested suited for EV use as the calendar...
  33. F

    Tesla's 85 kWh rating needs an asterisk (up to 81 kWh, with up to ~77 kWh usable)

    No problem. If you are interested in why a long-term self discharge test is used by Tesla (which actually degrades the cells before they are even built into a pack and is view by bean counters as a "waste" of money)...
  34. F

    Tesla's 85 kWh rating needs an asterisk (up to 81 kWh, with up to ~77 kWh usable)

    That's fine but I'm still not going to answer it. I'm sure others will. For another reference point let's look at another manganese cell used this time in the Chevy Volt, which only operates over a very tiny ultra conservative charge/discharge band (hybrid). Here is the Constant Power...
  35. F

    Tesla's 85 kWh rating needs an asterisk (up to 81 kWh, with up to ~77 kWh usable)

    That is such a stupid question I am not about to dignify it with a real response
  36. F

    Tesla's 85 kWh rating needs an asterisk (up to 81 kWh, with up to ~77 kWh usable)

    What are you even getting at. Elon will actually tell you Tesla stock is overvalued when it is overvalued. He cares so much about the mission he often cries. Not a sign of an ego maniac ill bent on pumping up the stock price. You think the Model X design shows profit is the chief concern? Tesla...
  37. F

    Tesla's 85 kWh rating needs an asterisk (up to 81 kWh, with up to ~77 kWh usable)

    You don't know how wrong you are. Anyway all this 40 pack talk is besides the point. The point is Tesla's 85kWh rating is correct and ~81kWh measured on a relatively new pack is to be expected given the cell chemistry. There is no hype or spin. That is how the industry rates battery packs. No...
  38. F

    Tesla's 85 kWh rating needs an asterisk (up to 81 kWh, with up to ~77 kWh usable)

    it wasnt that they couldnt make a long life 40 pack it is just performance and pack life are intertwined Tesla chose the less profitable route that was best for its customers
  39. F

    Tesla's 85 kWh rating needs an asterisk (up to 81 kWh, with up to ~77 kWh usable)

    it is not a claim. that is the reason I have been told in person the article we both linked to says as much in print if you read between the lines "there was more to it than that" meaning the demand wasnt the reason the 40 was canceled. The 40 kWh tier was unceremoniously killed on April...
  40. F

    Tesla's 85 kWh rating needs an asterisk (up to 81 kWh, with up to ~77 kWh usable)

    ""When we were testing the 40 kWh pack, it was kind of a sluggish car. It didn't feel good. It didn't feel like a Tesla."" -Elon
  41. F

    Tesla's 85 kWh rating needs an asterisk (up to 81 kWh, with up to ~77 kWh usable)

    That is wrong. The 40 was discontinued for two main reasons: 1) It didn't feel like a Tesla when Elon drove it. It was too slow (based on the max allowable amp draw on each cell that would still yield on long life 40 pack) 2) They could not guarantee the pack would not rapidly degrade given how...
  42. F

    Tesla's 85 kWh rating needs an asterisk (up to 81 kWh, with up to ~77 kWh usable)

    Tesla's only obligation is to rate the pack at or below rated capacity of the cells.In case of the 60 kWh model they underrated the battery for two reasons: 1) to get more people to upgrade to the 85 kWh pack with a larger difference "on paper" (duh) 2) the smaller pack needs more leeway to...
  43. F

    Tesla's 85 kWh rating needs an asterisk (up to 81 kWh, with up to ~77 kWh usable)

    The 85kwh rating is in no way a scam. That is below the true rated capacity. While Wk can claim to be Tesla battery expert, he is in no way a Tesla cell expert. He is the most valuable member on the forum, and the information he is providing is very valuable, but be careful interpreting what he...
  44. F

    Tesla's 85 kWh rating needs an asterisk (up to 81 kWh, with up to ~77 kWh usable)

    that is only true because they have no competitors now. but be assured ALL the major automakes have Tesla killers in the stable and Tesla has no idea when they will be released. one thing you can be sure of is they will play every trick in the game book when advertising their cars. the will use...
  45. F

    Tesla's 85 kWh rating needs an asterisk (up to 81 kWh, with up to ~77 kWh usable)

    Tesla never lied. The motor power rating is technically correct on all the cars they have sold and so is the battery rating. They play the same game as everyone else. Given time all cars will be required to be sold with an actual usable capacity rating but even then some people will never be...
  46. F

    Tesla's 85 kWh rating needs an asterisk (up to 81 kWh, with up to ~77 kWh usable)

    the worst thing about nca cells is they rapidly degrade. the best thing about nca cells is the degradation quickly levels out. this applies to both cycling and calendar again Panasonic performs a short term self discharge check at full voltage at the factory and then Tesla does their own...
  47. F

    Tesla's 85 kWh rating needs an asterisk (up to 81 kWh, with up to ~77 kWh usable)

    your forgetting to account for the 4kwh lead acid battery! haha jk this NCA cell only delivers the rated capacity maybe 1-3 times if discharged at 0.1C and the cell is brand spanking new by the time the cell is installed in a pack and sold it is already a few months old and has undergone...
  48. F

    LG Bolt - Chevy Bolt made in Korea

    Thanks for the links. It is interesting they claim the inverter is a GM design since LG "will also manufacture the car's power electronics modules to specifications mandated by GM." That doesn't sound like it is a "GM Design" as they claim. I wish I could claim I was a power electronics...
  49. F

    LG Bolt - Chevy Bolt made in Korea

    Thanks for telling me what the thread is about. I wasn't really sure with the title being 'LG Bolt - Chevy Bolt made in Korea' Please stop trying pigeonhole the thread. Thanks! The LG Bolt is an Electric Vehicle. The main topic of the thread is anything related to LG's involvement in the Bolt...

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