Model Y Long Range constantly showing 315-317 mile range when fully charged.

[sublimejackman]

No. Some of us just understand that it isn’t related to the current discussion in any way, shape or form.

From the OP "First time Tesla owner here, and my car is about 10 months old. Is it normal for my Long Range Model Y to be showing no more than 317 miles (sometimes as low as 315) when charged to 100%?"

This goes to the heart of this discussion. Why is my car showing X number and others are showing Y number and Tesla said Z number.

For the purposes of this discussion, damage and degradation are synonymous.

Well then just parking your car at 75% is "damaging" the battery? The battery is a comsumable item, it wears out with use. That's seperate from damage.

 

[ucmndd]

This goes to the heart of this discussion. Why is my car showing X number and others are showing Y number and Tesla said Z number.

Measuring degradation is simple: current pack capacity divided by pack capacity when new equals degradation in percentage.

317 (current) miles divided by 330 (when new) miles = 96% of capacity vs. new - i.e. 4% degradation.

As you’ve already been told repeatedly, the range number on the Tesla display is simply calculated battery capacity divided by a constant (EPA rated efficiency). It matters not one bit what that constant is when calculating degradation as a percentage.

If Tesla was more realistic about actual range and rated the MYLR at 300 miles instead of 330, OP’s reported range would be 288 miles - THE SAME EXACT 4% DEGRADATION.

For the last time - EPA rated range is meaningless when calculating battery degradation.

Well then just parking your car at 75% is "damaging" the battery? The battery is a comsumable item, it wears out with use. That's seperate from damage.

In the context of lithium batteries, degradation IS chemical damage - be it from calendar aging, temperature, or fast charging. It is the same chemical process. There is no difference.

 

[AAKEE]

First time Tesla owner here, and my car is about 10 months old. Is it normal for my Long Range Model Y to be showing no more than 317 miles (sometimes as low as 315) when charged to 100%?

The expected degradation after 10 months for a Panasonic cell is a cording to this:

The battery will degrade about like this even if you do not drive.

I guess Boston has an average climate?
The average cell temp matter as much as the state of charge.

330 miles equals about (at least) 79kWh I guess, as the M3LR has 79 kWh as the degradation threshold fir the same battery.
That would set the by BMS estimated capacity to about 76.1 kWh.
These batteries seldom go above 80.5-81 kWh capacity according to the BMS so 76.1 put us at about 5.5% degradation (using 80.5 as the base).

If we look at the chart above, we would expect to loose about 5% from calendar aging in a normal climate (cells average a bit above the average ambient temp due to charging and use) if we did keep the battery SOC mostly above 60%.
(The charts is for 10 months as well so no calculation needed.)

In your case, if you had the car around 50% most of the time, we could expect less degradation.

Cyclic aging (charging/discharging ) in general cause quite little degradation over one year. Almost neglible.

This is also a reason that cars driven very little often should look worse in graphs like teslafi, as they have aged more before it reach the same miles as the cars driven more.

The BMS can be off with the capacity estimate. If you are worried, you could try the BMS calib tricks.

I would say that degradation is very predictable so in your case I would say that if you mostly kept 50% (not above 55%) you should have relatively low degradation.

If you mostly kept 60% and more you’re on track!

 

[AAKEE]

Measuring degradation is simple: current pack capacity divided by pack capacity when new equals degradation in percentage.

317 (current) miles divided by 330 (when new) miles = 96% of capacity vs. new - i.e. 4% degradation.

See my post above about the degradation.
I suspect the MYLR use the same 79 kWh degradation treshold as the model 3 do with the same battery. So, then the degradation from the starting value is higher at 317 mi.

 

[Webeevdrivers]

For what it’s worth, we live in a place where using teslas EPA test numbers closely match those of the real world. In the summer time if I drive up and down the length of the Okanagan valley, (so vernon to Osoyoos and back) I can pretty much get the tesla EPA numbers. It’s just the right combination of highway, city, lots of little towns, uphill, downhill etc. Pretty easy to get EPA numbers on this route.

Jmho.

 

[AlanSubie4Life]

All stuff I addressed in my first post

See my post above about the degradation.
I suspect the MYLR use the same 79 kWh degradation treshold as the model 3 do with the same battery. So, then the degradation from the starting value is higher at 317 mi.

Agreed - and I think we have verified this MY threshold in the past (just need to know the constant and multiply by the EPA rated range). So a couple % or so hidden there.

 

[sublimejackman]

Measuring degradation is simple: current pack capacity divided by pack capacity when new equals degradation in percentage.

317 (current) miles divided by 330 (when new) miles = 96% of capacity vs. new - i.e. 4% degradation.

As you’ve already been told repeatedly, the range number on the Tesla display is simply calculated battery capacity divided by a constant (EPA rated efficiency). It matters not one bit what that constant is when calculating degradation as a percentage.

If Tesla was more realistic about actual range and rated the MYLR at 300 miles instead of 330, OP’s reported range would be 288 miles - THE SAME EXACT 4% DEGRADATION.

For the last time - EPA rated range is meaningless when calculating battery degradation.

The literal only number that matters is kwh when discussing the battery. Literally any other number, reported by the Tesla API is made up. That "battery_range" field is completely divorced from reality. It's not an exstimate based on past driving, it's not the EPA range. It's a number manipulated by Tesla with an algorithm when the SoC is greater than 50% to artifically inflate the range displayed. Then a completely seperate methodology is used as the battery drains. This is known, not controversial. We have all personally experienced it and recently a bunch of Tesla employees have specifically stated they do this.

In the study's notes, they say this is the number they use. A MADE UP NUMBER.

"response": {
"battery_heater_on": false,
"battery_level": 90,
"battery_range": 224.47,....}"

 

[AAKEE]

The literal only number that matters is kwh when discussing the battery. Literally any other number, reported by the Tesla API is made up.

Thats not really true.

The displayed range is the energy of the buffer plus a fixed a amount of energy per km (or miles).
(The buffer is 4.5% of the nominal full pack)
We can calculate this for your car as well.

 

[sublimejackman]

Thats not really true.

The displayed range is the energy of the buffer plus a fixed a amount of energy per km (or miles).
(The buffer is 4.5% of the nominal full pack)
We can calculate this for your car as well.

Knowing the algorithm doesn’t change how it is divorced from reality. If the car always multiplies a fixed kwh/mi x battery percentage + 4.5% how is this number suited for measuring battery degradation? If the percentage is always multiplied by the same nominal consumption?

The chart in the study shows as percentage of the reported range in miles. Using this logic, the reported range should always be the same at the same percentage.

Lastly, the entire methodology of the study is flawed. Cars who charge via superchargers 90% of the time could supercharge weekly, then rarely level 2 charge. Cars that supercharge 10% of the time could charge at home everyday then supercharge once every 10 days. The difference between those two is the one that supercharges 10% of the time uses MORE battery and cycles more frequently.

This whole thing is a mess and because Tesla lies and then people here defend it.

All I wanted to do was give one person some pretty damn good advice for a long life with their car.

 

[ucmndd]

Lastly, the entire methodology of the study is flawed. Cars who charge via superchargers 90% of the time could supercharge weekly, then rarely level 2 charge. Cars that supercharge 10% of the time could charge at home everyday then supercharge once every 10 days. The difference between those two is the one that supercharges 10% of the time uses MORE battery and cycles more frequently.

More complete and utter nonsense. Just because a study contradicts your deeply held personal biases doesn’t make it flawed.

With an N > 4,000, any such statistical outliers as you describe above are well controlled for. You’re just looking for reasons to confirm what you want to believe is true.

 

[sublimejackman]

More complete and utter nonsense. Just because a study contradicts your deeply held personal biases doesn’t make it flawed.

With an N > 4,000, any such statistical outliers as you describe above are well controlled for. You’re just looking for reasons to confirm what you want to believe is true.

My man. I personally have driven 150k miles. 40k of which supercharging. I still would be in the in the <10% category cause I charge at home daily.

Just cause you have a lot of people, doesn’t mean you control for these types of cases.

Lotta people who exclusively supercharge work from their apartment. It’s why they can have a Tesla and not a place to regularly charge. They drive less than a 100mi a week but that’s against my 500mi+ weekly average.

This, again, isn’t to mention the thousands of studies out there that show that lithium based batteries degrade faster when charged at a faster rate. The burden is this study to show that Tesla truly has come up with a breakthrough, one I’m sure they’d be bragging about right now if they had.

 

[sublimejackman]

More complete and utter nonsense. Just because a study contradicts your deeply held personal biases doesn’t make it flawed.

With an N > 4,000, any such statistical outliers as you describe above are well controlled for. You’re just looking for reasons to confirm what you want to believe is true.

WAIT this is the best part…
Their conclusion was the same as mine!

I said:

“Supercharging degrades that battery faster than home charging. But not enough that you should avoid road trips…but newer batteries and better cooling systems allow for faster charging with less degradation”

The study said:

“Will fast charging hurt my EV battery?
The short answer is that occasional fast charging is fine.“

This is literally crazy town.

 

[ucmndd]

My man. I personally have driven 150k miles. 40k of which supercharging. I still would be in the in the <10% category cause I charge at home daily

You’re inferring a structure to this study which while possible would be pretty stupid. Why on earth would they count “charging sessions” vs. energy actually added to the battery? Given your numbers, you’ve supercharged 27% of the time (27% of the energy cycled through your pack was added via DC fast charging).

I don’t see any detailed methodology on their blog post to confirm their approach, but again I’ll say that your approach would be nonsensical and it’s immediately obvious that there’s a better way, so I struggle to think you’re correct.

This, again, isn’t to mention the thousands of studies out there that show that lithium based batteries degrade faster when charged at a faster rate.

Then surely you could cite one or two of the “thousands”, and quantify such qualitative and relative terms as “faster rate?”

There’s nuance to all of this that you either don’t understand or are casually dismissing to confirm your deeply held belief.

“How fast” matters. An actual expert in one of your own citations upthread said damage starts around 4C, which no Tesla pack charges at. You responded to this by creating your own arbitrary distinction between damage and degradation.

“How cold” matters a great deal too. Damage due to fast charging greatly accelerates when cell temp is low. That’s why Teslas aggressively precondition (heat) the battery when navigating to a supercharger and aggressively limit max power when the battery is cold.

If you control for these two main variables it appears you can fast charge at acceptably quick rates that have a negligible impact on battery life compared to all the other factors that cause cells to degrade.

That’s good news for everyone, even if you can’t bring yourself to believe it.

 

[sublimejackman]

You’re inferring a structure to this study which while possible would be pretty stupid. Why on earth would they count “charging sessions” vs. energy actually added to the battery? Given your numbers, you’ve supercharged 27% of the time (27% of the energy cycled through your pack was added via DC fast charging).

I don’t see any detailed methodology on their blog post to confirm their approach, but again I’ll say that your approach would be nonsensical and it’s immediately obvious that there’s a better way, so I struggle to think you’re correct.

Then surely you could cite one or two of the “thousands”, and quantify such qualitative and relative terms as “faster rate?”

There’s nuance to all of this that you either don’t understand or are casually dismissing to confirm your deeply held belief.

“How fast” matters. An actual expert in one of your own citations upthread said damage starts around 4C, which no Tesla pack charges at. You responded to this by creating your own arbitrary distinction between damage and degradation.

“How cold” matters a great deal too. Damage due to fast charging greatly accelerates when cell temp is low. That’s why Teslas aggressively precondition (heat) the battery when navigating to a supercharger and aggressively limit max power when the battery is cold.

If you control for these two main variables it appears you can fast charge at acceptably quick rates that have a negligible impact on battery life compared to all the other factors that cause cells to degrade.

That’s good news for everyone, even if you can’t bring yourself to believe it.

This could all be resolved by using kwh added by what means (SC vs level 2) and then normalizing that by miles driven over time.

(some strange reason, I have a weird feeling that graph would look VERY different, studies that confirm other studies don’t get much attention)

But that’s not what we have. we have a vaguely worded survey of range reported in the car. Which again, has no basis in reality.

It’s like I’m taking crazy pills. Like Tesla, the study, everyone here could all resolve all of these issues, if the damn car reported numbers based on reality.

My friends 2003 Suburban can predict range based on previous driving. In 2017, A Better Route Planner could accurately predict range based on weather, road type, speed and elevation. This isn’t that hard.

But alas, here we are

 

[GHammer]

It's a number manipulated by Tesla with an algorithm when the SoC is greater than 50% to artifically inflate the range displayed. Then a completely seperate methodology is used as the battery drains. This is known, not controversial. We have all personally experienced it and recently a bunch of Tesla employees have specifically stated they do this.

Really? In 9 years, 3 Tesla's and 370k miles I have never heard of, or experienced this. Can you provide substantiation for this?

 

[AAKEE]

Knowing the algorithm doesn’t change how it is divorced from reality. If the car always multiplies a fixed kwh/mi x battery percentage + 4.5% how is this number suited for measuring battery degradation? If the percentage is always multiplied by the same nominal consumption?

There is ways to calculate the bsttery capacity by your self.
I did it with the old car and drove from 100 to zero (described in the other post).
It matched.

I did it on my MSP, as it started with a nominal full pack of 95.7 which sounded wrong. The numbers hit 98-98.2 kWh, and the car/BMS also eventually hit 98-98.2 kWh.
(I have described the capacity calc in a few posts here on TMC.)

We can calculate the capacity (done that - it matches) and we can perform a drive to test the outputed energy (done that, it’s a match). The BMS can be off from time to time, but the car actually tries to know the real battery capacity and the displayed range is a true split of the energy in the battery.
There is no faul play in this, really.

The chart in the study shows as percentage of the reported range in miles. Using this logic, the reported range should always be the same at the same percentage.

No, as the capacity estimate changes from time to time (also depending on that the battery capacity actually can go slightly up, not only down), the range displayed is (nominal remaining -buffer)/ the constant.

A lower capacity means that 100% SOC will be less energy, hemce each percent will be a shorter range.

There is no bull with the SOC either.
SOC is straightforward, displayed range is also.

Lastly, the entire methodology of the study is flawed.

I guess you are talking about the fast charge / supercharging study?

I think you and I are quite agreeing about the fast charging degradation. I did not read all the posts bit my personal view is that it wears, and probably much more than that study shows.
It might be that the capacity do not go down very much but if supercharging or fastcharging much enough / to often, one day the lithium plating cause a short in one or more cells and than we have a problem.

I know of a swedish M3P mostly supercharged (~55 or 60 MWh supercharging), that killed the battery with what seemed about 12% degradation (SMT used so capacity wise). My take from that was that the lithium plating from extensive supercharging did it.

 

[sublimejackman]

I guess you are talking about the fast charge / supercharging study?

Yeah. I think that is where you and I are disconnecting. I’m strictly talking about the study when I say the methodology is flawed. Otherwise, I think we are on the same page here.

I get that the reported SoC in percent is a good faith representation of the battery’s current condition. That’s not my issue and that’s not what I’m saying Tesla is lying about.

Every other car ever made before a Tesla and every other ICE car on the road reports “range” as an estimate based on remaining fuel and previous driving.

Tesla, however, on the dashboard, reports a number that is completely different. Leading many (if not most) to be confused on why that number is rarely accurate (often by an anxiety inducing margin).

This confusion could be easily remedied by Tesla by doing one or both of the following:

1. Changing the marketing around EV range to reflect the dynamic nature of EV performance and the inevitable degradation they all experience in the first year

2. Accurately display a remaining range based on current and past driving conditions (as mentioned earlier Tezlab, ABRP, etc all do this just fine)

And before someone says it, I understand that Tesla is reporting range in a way that is legal in the US. That doesn’t make it right or any less of a willful lie. Also, there is a lot of crazy stuff that isn’t illegal in the US, that’s a terrible argument.

 

[sublimejackman]

Really? In 9 years, 3 Tesla's and 370k miles I have never heard of, or experienced this. Can you provide substantiation for this?

Reuters article I posted the other day.

It’s surprising that you never noticed this. One of the first things I noticed with my first Tesla. That when SoC was high, the estimated range dropped significantly slower than when the SoC was lower.

This is the reason I switched to percentage mode after just a few months with my first Tesla.

Dozens of Tesla employees and leaked documents show this.

 

[GHammer]

Reuters article I posted the other

Dozens of Tesla employees and leaked documents show this.

Can you point me to those?

 

[sublimejackman]

nah

Can you point me to those?