Johan
Ex got M3 in the divorce, waiting for EU Model Y!
... Which should then have been labeled the Model S 300 [miles at 55 mph] or Model S 265 [EPA miles] which is true, but not Model S 85 [kWh battery].
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... Which should then have been labeled the Model S 300 [miles at 55 mph] or Model S 265 [EPA miles] which is true, but not Model S 85 [kWh battery].
Perhaps. Although nobody ever said that the model number has to correlate to some technical spec. The model number is just a label. They could have called it the Model S 31416 - which makes every bit as much sense as some of the model numbers out there.
Johan
Ex got M3 in the divorce, waiting for EU Model Y!
Tesla's 85 kWh rating needs an asterisk (up to 81 kWh, with up to ~77 kWh usa...
Fair enough. In that case read my post like this: the number 85, referring to kWh capacity of the battery pack should never have been used if the battery pack cannot deliver 85.000 VA of energy from being fully charged to completely discharged.
KWh is a unit and has a very specific and unambiguous meaning. 85000 kWhs is exactly defined, there's no margin for error or interpretation. It's an absolutely unambiguous amount of energy.
Fair enough. In that case read my post like this: the number 85, referring to kWh capacity of the battery pack should never have been used if the battery pack cannot deliver 85.000 VA of energy from being fully charged to completely discharged.
KWh is a unit and has a very specific and unambiguous meaning. 85000 kWhs is exactly defined, there's no margin for error or interpretation. It's an absolutely unambiguous amount of energy.
faughtz
Model S P85DL
We need a test of a brand-new Tesla 18650 that's never been cycled once, and is as fresh off the line as possible to reduce calendar-life degradation[1].
If that test reveals a number that logically rounds up to 85KWh (or at least nearer it than 80), then, I don't think there's an issue.
If Panasonic's own rating of the cells logically rounds up to 85KWh, then I don't think there's an issue.
In either case, I think the specification (if not the model # designation) needs to be accurate.
[1] Car that falls off the auto carrier and thus totaled? Although with test drives even "brand new" cars have miles and I suspect a charge cycle on them,,,
If that test reveals a number that logically rounds up to 85KWh (or at least nearer it than 80), then, I don't think there's an issue.
If Panasonic's own rating of the cells logically rounds up to 85KWh, then I don't think there's an issue.
In either case, I think the specification (if not the model # designation) needs to be accurate.
[1] Car that falls off the auto carrier and thus totaled? Although with test drives even "brand new" cars have miles and I suspect a charge cycle on them,,,
We have it from Jerome Guillien that the A packs do indeed use different cells. I think you just meant they each hold the same capacity?
If you are speaking of drivetrain efficiency (i.e. using 260wh/mi rather than 280), then that makes no difference in the amount of energy stored in the pack.
What that means if that you could go farther than previously on 81KWh with efficiency gains, then you should be able to go even farther still on 85KWh with those same gains.
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Hmm... I had recalled that the PACK was indeed different (hence the lower supercharger rates it could withstand) but not sure that it had quantified as differences in cells, cooling, etc...
I would like to see the internal report tesla from the tesla engineer. It might very well be the smoking gun needed by some lawyer for the class action. But until then we will not know. Again i highly doubt tesla will release such document. And i am sure they have all the engineers sign some nondisclosure to protect against such. The only way to get it is someone to sue and have a judge force them to release the document.
Anyways a side note if i rememeber correctly hyundai was force to correct their mpg on their elantra because no one was able to replicate their mpg. Not sure if they sued.
Aw come on. Engineers will find any excuse to get out of a meeting.
(So that at least part of this post is on-topic, let me say that I appreciate the work of wk057 and others related to discovering the Tesla Model S internals. The technical discussion on this thread is fascinating.)
Andyw2100
Well-Known Member
Tesla didn't need to include a point by point rebuttal to the Elektrek article. But assuming the packs ever --DO-- have 85 kWh power when delivered, how hard would it have been for Tesla to say that, or something like that? That omission was both glaring, and in my opinion, telling.
I vehemently disagree with this.
We didn't buy our cars from Panasonic. We bought them from Tesla. Tesla has a responsibility to us, their customers. Panasonic has a responsibility to Tesla and their other customers. If Panasonic got something wrong, Tesla can be upset with Panasonic, but we can rightfully be upset with Tesla.
Sweet, a vehement disagreement!
I'm assuming Panasonic used "industry accepted" methods to rate the cells (in other words, the same way every other cell you get from Panasonic, LG, etc... or the rating used on all your rechargeable tools, laptop battries, etc... that OEM such cells), then why not?
Note that this is very likely a lab-based rating that will never be reached in the real world after a cycle or two. But if you accept it with your Dell laptop and you DeWalt drill, why not your Tesla car?
JRP3
Hyperactive Member
Some are trying to claim that over time Tesla has lowered the actual capacity of the pack because over time they found they needed fewer kWh's to get the same range. IF that were true then the cars should reflect that increased efficiency. I don't believe that is the case.
Andyw2100
Well-Known Member
Just for a moment there I thought you were going to actually agree with me.
Your attempt to impugn wk057's work using my words, though, falls flat. My point was that we had seen only one example that was outside the data being presented by wk057, while there are many examples that support the data he has presented. Additionally there were probably explanations for how that one outlying example got there. As it turns out, some of my suggested possibilities are pretty close to some more realistic ones that wk057 proposed later.
There is a great deal of data that supports what wk057 has documented. I'm open to the possibility that somehow his conclusion is incorrect, as I expect is he, but it will take good, hard data to convince me of that. For now, wk057 has presented enough evidence that I believe what he has said is correct.
Oh man... we should just go over to the P85D HP debate. With a few carefully selected text search/replaces we can witness the next 100 pages of posts TODAY and save everybody a lot of typing. Maybe we should start a pool to count-down the number of posts before somebody uses the word "lawyer".
Maybe we should start a pool to count-down the number of posts before somebody uses the word "lawyer".
bonnie
I play a nice person on twitter.
Oh man... we should just go over to the P85D HP debate. With a few carefully selected text search/replaces we can witness the next 100 pages of posts TODAY and save everybody a lot of typing.
Too late. Tesla's 85 kWh rating needs an asterisk (up to 81 kWh, with up to ~77 kWh usable) - Page 4
As a matter of fact two of them were Tesla-owned demo cars with < 50 miles on them. One didn't even have the shipping protections removed yet. (No, this wasn't local, so no one go and try to get my local service center folks hanged or anything. And no, I'm not going to mention who/how/when/why/where/etc on this to protect the mostly-innocent.)
And I'm quite certain the capacity values reported by the BMS are very accurate (except in the case of a calibration issue from short cycling over an extended period). Additionally, the "60" BMS also correctly reports the capacity that matches external testing.
Yeah, this seems to be a recurring theme for some reason. There really is no getting out of this one. I wouldn't have posted the info if I wasn't certain it was correct. Reasoning behind why they marketed it as an 85 isn't particularly my concern. It's an ~81 kWh pack, it's marketed as an 85. This is false, end of story. There's no real way around that fact. Get over it, do something about it if you must, but don't deny it.
Interesting. I'd be curious to the source of that info from Jerome, personally. I have four A-pack cells in two of my custom cell torture devices still, and their characteristics match exactly (literally something like a 0.2% margin) of newer cells. I could even pretty likely accurately determine their cycle count by fitting their data with the newer cell data.
Calendar life degradation is virtually non-existent with these cells when stored properly (40-60% SoC, room temp or lower), which is impressive. Cycle count has a measurable effect on capacity, and seems pretty predictable for various condition sets.
Electricfan
Active Member
I just want to make sure I understand you. You're saying Tesla planned to use an 85 kwh pack, then changed their plan and knowingly reduced the capacity to 81 kwh, and its ok to put a sticker on the pack underneath the car that reads "85 kwh" when they know it only has 81 kwh in it?
Do I have that right?
So its ok with you that this sticker says 85 kwh, when Tesla knows it is really 81 kwh?
stopcrazypp
Well-Known Member
Hyundai was forced to do that because the EPA audited them and found out they did not follow proper procedures for the EPA test cycle. It was not because an internet commenter claimed their MPG couldn't be matched (putting aside for the moment that there is no such standardized test procedure for battery capacity claims).
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