Umm... no it doesn't? How so? Care to explain? No, you're just throwing nonsense around.
I don't hold punches. When someone spews nonsense, I call it what it is. Can't take it? I suggest you play elsewhere.
Why I'm going to bother wasting time explaining why you're full of crap here yet again is beyond me, but here it goes.
No, there isn't. The diag_vitals data that Tesla logs only reports one capacity value, and I noted that the values I reported were usable energy as reported by the BMS. I suggest you go back and read those posts before making baseless claims.
No, I fully explained that the number is the result of a pre-calibration value programmed into the BMS at the factory. This will yet again be me saying the same thing. "Hello! Anybody home? Think McFly! Think!" You want to keep hammering at this because it's basically the only thing that would seem to support your position, yet doesn't stand up to any scrutiny whatsoever. You're the one who prefers to harp on it because the truth doesn't fit your story. And just to be clear, I tell no "stories", either. Everything I write is backed up by the facts and the numbers. If I'm speculating, I specifically say so.
Of course I dismiss it, and have explained exactly why. In this case, you won't even explain why such speculation is worthwhile. Why? Why does it matter why some engineer put a starting value in for capacity calibration that's never correct? I'm pretty sure the speculation wouldn't support your case at all anyway, so let's waste everyone's time on it for a moment.
<speculation>
Hmm, so let's pretend I'm an engineer at Tesla. I'm working on the BMS software. I need a way to get the calculated capacity as close to the actual value in as few cycles as possible. I know that the software is designed to downwardly adjust the available capacity estimate much more quickly towards an accurate value since capacity loss is a normal aspect of the battery pack and magical capacity increase is not. Capacity can be lost due to imbalances, degradation, etc. But all of the battery packs are different. I know that 265 miles of rated range is the target. (RWD variants, since this is engineering that occurred at that point.) 265 miles is 78.175 kWh of capacity, plus the 4 kWh of bottom buffer is a target of 82.175 kWh. Ok, good. So we'll set the initial calibration capacity to some arbitrary amount above that... say, 2.5%? Then the BMS will quickly calibrate downward over the first couple of cycles to towards the correct capacity. And it's pretty unlikely that anyone will drive the car to 0% on the first charge or two. After a few cycles everyone will settle to around 265 miles, and everyone will be happy. Win win!
</speculation>
<speculation>
Marketing Department: We need it to look like these have 85 kWh
Engineering Department: But it will just correct itself anyway.
Marketing Department: Just do it.
(Engineer still puts in 84.6 kWh)
</speculation>
<speculation>
Engineer 1: These are the specifications targeted for the battery pack.
Engineer 2: Cool, but the batteries don't actually have that much capacity.
Engineer 1: Well, our software will correct it quickly, so doesn't matter and it keeps marketing off our backs.
Engineer 2: Good point. git commit (or actually svn, since Tesla used svn in the early days)
</speculation>
<speculation>
Panasonic: Our batteries have this much capacity
Engineer: Great, we'll program the BMS with this
* Panasonic walks away with sack of cash
</speculation>
Obviously the speculation can go on and on... but for what? What good does this do? There is no scenario that matters nor makes the initial calibration value relevant because it doesn't match any real world value.
So again, as much as you might want to scream that the reason they chose the number matters... it just doesn't. The engineers put a number in that works for the project and that's basically the end of the story. It has no bearing on actual capacity.
lol. Again, actually read my posts if this matters so much to you. I'm not going to hold your hand through that by copy/pasting things for you. I clearly explained where the initial data came from and my methodology. I clearly explained where the updated data came from (containing multiple orders of magnitude more data points). Obviously even if I went and bought multiple brand new 85 kWh cars from Tesla, towed them from the factory myself with the HV systems disabled, then dismantled the packs for testing..... I still wouldn't end up with as much data as Tesla themselves have in the database that I was provided by an insider. Why is this even a question?
So, let me get this straight. Your argument that there is no "missing" kWh is based on a couple of things.
First, you claim total capacity is 84-85 kWh. Let's start with that. I'll reiterate that I have zero.... that's read z-e-r-o or "0"... data points from THE ENTIRE TESLA FLEET WORTH OF DATA that shows a single vehicle having a usable capacity of 81 kWh or more (total of 85 kWh or more). Zero. ZERO. ZERRRRRRRO.
Next, you cite "multiple data points" where usable capacity is between 80 and 81 kWh. Sure, I never said that wasn't the case. But you're taking some extreme edge cases as if they were normal. Yes, there are a handful (literally less than 200 or so out of something like 88,000) of "85" vehicles that have capacities that would almost not be criminal to round up to "85". As for basically everyone else... the other 99.9% of "85" vehicle owners.... yeah, sorry, you don't have anything close to 85 kWh of battery capacity and you never did.
And the EPA testing is just pointless. I've no idea how they come up with their numbers. They literally don't match real world data for any car. 95.507 kWh recharge from the wall event on an 85 kWh pack? That's only possible at like 5A on 120V or something ridiculously inefficient. Or with extreme pack heating needed. Or running HVAC at full blast while charging. Or any other number of reasons that make that number completely outrageous. That's a wall->wheels number of over 360 Wh/mi for a RWD 85's rated mileage.
FACT: I just drove my car down to 1 mile of range a few weeks ago and then charged to 100% from AC power. This is a newish good condition "90" pack that shows 83 kWh usable (87 kWh total capacity). The recharge event pulled 93.8 kWh from the wall. So, my "90" pack that has ~281 miles of rated RWD range at 100% charge pulls less power from the wall than the EPA calculated for an "85" with, for the sake of argument lets say it showed 272 miles of range. lol. Come on now really?
Finally, I'll apologize to everyone else here on this forum who benefits from and enjoys my technical posts and knowledge sharing. Suffice it to say @vgrinshpun has once again reminded me why I can't post such things here and why TMC still is still not the correct venue for technical discussions about anything that can possibly shine a bad light on TSLA. I simply don't have the time to bother with battling people who will defend Tesla to the death no matter what they do wrong, and this post is proof of that again. I'm 100% certain that there will be yet another response trying to take attention away from the facts, but I'm not going to bother anymore, so don't take my lack of further response here as lack of support for the actual facts. They still stand regardless of what spin people may try to put on them. (Statistics show that teen pregnancy rates drop dramatically after age 20!)
Until TMC decides to finally implement some form of self-moderation so that technical discussions can be kept clear of baseless and useless speculation and other pointless discussions that detract from the usefulness of the data and technical points themselves, or finds some better way to partition technical topics (there isn't one).... I'm going back to limiting my TMC use to the classifieds section and responding to reasonable PMs and highlights.
Data from Tesla EPA certification application dated 12/02/2014 indicate that:
- usable capacity of 85 kWh battery based on C/3 discharge rate is 83 kWh
- usable capacity of 85 kWh battery based on discharge rate to support EPA City Cycle Testing is 80.640 kWh
- usable capacity of 85 kWh battery based on discharge rate to support EPA Highway Cycle Testing is 80.731 kWh
Excerpt from the Tesla EPA Certification Application dated 12/02/2014
Link
https://iaspub.epa.gov/otaqpub/display_file.jsp?docid=34511&flag=1
