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AlanSubie4Life
Efficiency Obsessed Member
This is not correct. New 2020 vehicle parameters cannot be applied to your vehicle. That vehicle has a different constant. It is not valid to use it.
Your first calculation is correct, it is just optimistic because it does not show the "hidden" degradation that likely occurs on new vehicles.
That would be pretty shady, for obvious reasons (constant shenanigans...). It's only fair that it be based on an energy benchmark from a vehicle with about 1000 miles on it (like the EPA test vehicle) (whatever that value may be). I can't see any reason why not to use the EPA kWh number as the original value, as that is what is required to obtain the EPA rated range, and that's what people would presumably be expecting! (I'm assuming that those kWh are scaled the same way as the ones displayed on the CAN bus - if not, obviously you'd need to apply appropriate scaling.)
By this logic, someone buying an 18" 2020 Performance vehicle today could switch their configuration to 20" wheels (without changing the vehicle or wheels in any way) and immediately claim 7.2% degradation!
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Isn't it just measured by what the total is when 100% charged? why would wheels matter if it's measured that way?
AlanSubie4Life
Efficiency Obsessed Member
A 2020 Performance Model 3 vehicle with 18" wheels selected could display 322 rated miles, and if you then change the wheel configuration to 20" wheels (without making any changes to the vehicle) that same vehicle would display 299 rated miles.
The energy doesn't change, of course! But that's my point. Using rated miles is silly - they could mean anything - and there's some evidence that they DO change in size initially for Model 3.
Show me where the battery capacity is specified by Tesla. Pretty sure there is no number. Range is about it.
And honestly, it's what they decide to read out of the battery. It's pretty obvious when a battery is failing to 70%.
AlanSubie4Life
Efficiency Obsessed Member
Here you go:
It's all specified very clearly here directly by Tesla in a document generated by Tesla - there is no ambiguity, and these are the energies that are required to be available in order to make the rated range (except in the case of voluntary reductions):
https://iaspub.epa.gov/otaqpub/
To make it easy, I've tabulated it here; these numbers are taken directly from that website:
2020, 2019, 2018 Model 3 Battery Capacities & Charging Constants
AlanSubie4Life
Efficiency Obsessed Member
I was just using this as an example to demonstrate that using rated miles is silly - they could mean anything - and there's some evidence that they DO change in size initially for Model 3. When they decay below a certain size, then your rated miles start to go down. So you have loss of capacity (potentially) even when your rated miles are the same as they were when you bought the car. That's what the evidence we have so far points to. There may be some other explanation, but that is what I have come up with to fit the evidence so far. You start with nice fat rated miles, then they slim down a bit, then they start to disappear.
That's why I'm saying just use available energy. It's much less ambiguous (assuming no shenanigans, of course).
Most specifically, from the Tesla New Vehicle Limited Warranty
"The measurement method used to determine Battery capacity, and the decision of whether to repair, replace, or provide reconditioned or remanufactured parts, and the condition of any such replaced, reconditioned or re-manufactured parts, are at the sole discretion of Tesla."
Yep, Tesla will make the decision, it is NOT based upon miles NOR original battery capacity.
I'm going to guess that it's based upon the number of cells that have gone bad in the pack.
"The measurement method used to determine Battery capacity, and the decision of whether to repair, replace, or provide reconditioned or remanufactured parts, and the condition of any such replaced, reconditioned or re-manufactured parts, are at the sole discretion of Tesla."
Yep, Tesla will make the decision, it is NOT based upon miles NOR original battery capacity.
I'm going to guess that it's based upon the number of cells that have gone bad in the pack.
AlanSubie4Life
Efficiency Obsessed Member
It actually doesn't specify in any way. This phrasing looks like it applies to the capacity of the pack, but doesn't really address the question of what value to compare to.
But anyway, this is why there are lawyers. I think it would be pretty easy to argue that it should be based on the kWh measured on the original test article (after accounting for any scaling applied to convert Tesla measured EPA kWh to those displayed by the car's BMS - as they may not be calibrated exactly the same way - though we know anecdotally they are within about 1% so not likely to be a major issue).
No, the configuration of the car, ie. the wheels, would need to match the Monroney sticker so that the calculation was comparable. (This wasn't a problem in the past because Tesla didn't take wheel changes into account before.)
AlanSubie4Life
Efficiency Obsessed Member
Well, I think this settles the question then
It actually doesn’t answer your original question at all - what are they comparing to? The other quotes from other sources you posted saying the range is based on “fixed EPA data” suggests that could be their benchmark. It is an unanswered question though and you would have to ask just the right questions at Tesla to a knowledgeable person, to find out.
Of course the measurement of the existing pack is up to Tesla and they would have the option of resetting it, rebalancing it, etc., before measuring. But they still have to use a valid method even if it is their choice. They can’t just make up numbers. Again, this is unfortunately why lawyers exist.
the question is that if you can charge it to desired percentage. if you set to charge to 90 percent and it only goes to 88 percent then there is a problem. based on your location, I would think the cold climate makes the computer compensate the range. Range will come back during summer. there is nothing to worry about.
I think that it really does answer the question. "Whatever they feel like" seems to be the answer.
I've got a feeling that they are going to replace batteries well before they hit 70%. But it's not going to be on range, it will be on the number of individual cells that have failed. They don't want the press release talking about batteries failing.
This "my range is 10% less" crap is just that. Crap from folks with range anxiety and folks watching apps that are only giving guesses. It's just not accurate.
AlanSubie4Life
Efficiency Obsessed Member
So far I have not seen any evidence that warm battery rated miles are not a very accurate indicator of energy available, when correlated with CAN bus data, once you degrade below 76kWh for an LR. So I feel it is inaccurate and misleading to say it is inaccurate.
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Bill Foster
I'm going home!
update:
got an answer from the service center: my car throretical maximum capacity was and is always going to be 380km
Cars from nov 2019 onwards have had their motors changed and the new ones are more efficient, not going to happen to mine
So, as of now, I have 6% degradation after 6 months, which is allegedly normal
SC told me they will do nothing until deradation hits 30% loss of 380km
got an answer from the service center: my car throretical maximum capacity was and is always going to be 380km
Cars from nov 2019 onwards have had their motors changed and the new ones are more efficient, not going to happen to mine
So, as of now, I have 6% degradation after 6 months, which is allegedly normal
SC told me they will do nothing until deradation hits 30% loss of 380km
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