What is the deal with the Model X 100D range ratings?

[lymex2018]

Let's get to it the other way around.
The rated mile on X 100D is currently 332 Watt/mile (changed in 17.26.76, used to be 324 before that). Multiply your 100% charge rated range by 332 and you have roughly your usable capacity, +4kWh for the buffer will give you 100% battery capacity.

I do not disagree with this calculation, but I cannot confirm it either because mine is different(metric system and NEDC rated instead of EPA rated).

However, the energy data should be the same and I didn't say that 98.4kWh is not the usable. It just because from SMT that 94.4kWh literally means 'Usable full pack'.

Also from one of my charging data from 0% to 100%(of the dash SOC), 'Usable remaining' of SMT is changing from -0.2kWh to 94.2kWh.

 

[apacheguy]

The issue here is whether the BMS_energyBuffer should be add to or subtract from the BMS_nominalFullPackEnergyRemaining.

Add: at one point, the Usable full pack of my car was 94.3, 0.1kWh less, and so was Nominal full pack. The difference of the two items is always 4.0kWh.
View attachment 278190

This is incorrect. EnergyBuffer definitely gets added to nominalfull pack for the true capacity.

 

[lymex2018]

This is incorrect. EnergyBuffer definitely gets added to nominalfull pack for the true capacity.

Then what's the point having this buffer, since no one is able to use it.

Refer to Bjorn's video:

The other guy is I believe from Tesla who was using Tesla diagnostic tool to see Bjorn's P90D. At 3:15 he said: your pack is 80.4kWh total, and we have to subtract 4 to get down to zero.

 

[verygreen]

Then what's the point having this buffer, since no one is able to use it.

Cars with limping batteries like 90 kWh packs do get to dip into the buffer, but basically the buffer is there to improve the pack longevity since the liion batteries hate full discharge.

 

[lymex2018]

Cars with limping batteries like 90 kWh packs do get to dip into the buffer, but basically the buffer is there to improve the pack longevity since the liion batteries hate full discharge.

Like I've already said that there are two buffers. They dip into the first but not the second. If you add that 4kWh to 98.4kWh then that 4kWh is the second/bottom buffer which no one is able to access.

 

[ChadS]

There are about a dozen threads on this already, but just briefly:

That picture does NOT come from Tesla. It is NOT accurate. THERE IS NO "ZERO MILE" PROTECTION BUFFER! There never has been. Tesla has denied it; it does not fit in with their marketing; it does not lend owners any benefits, and real-world experience shows it does not exist.

Some people luck out and go past zero because estimating zero is incredibly complicated (which is why this myth persists), not because there is a buffer. Many others have reported running out at or even a little before zero.

 

[skilly]

There are about a dozen threads on this already, but just briefly:

That picture does NOT come from Tesla. It is NOT accurate. THERE IS NO "ZERO MILE" PROTECTION BUFFER! There never has been. Tesla has denied it; it does not fit in with their marketing; it does not lend owners any benefits, and real-world experience shows it does not exist.

Some people luck out and go past zero because estimating zero is incredibly complicated (which is why this myth persists), not because there is a buffer. Many others have reported running out at or even a little before zero.

While the picture may not be an accurate representation of what is going on, I dont think its "luck" that gives owners mileage past zero. Id call it an unplanned side effect of the complicated math. And depending on the factors, it can be quite substantial - I have drive 20 miles on a "0 miles left" battery.

Both of my Telsas will go quite far past zero. While that is a small sample size for sure, its still 100% my experience, and I would challenge anybody reporting anything otherwise; especially with the X or Performance Cars - you would have to be so incredibly soft with your driving to keep the algorithm from breaking... The mileage available is almost always off in its estimates due to the variables.

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[chillaban]

While the picture may not be an accurate representation of what is going on, I dont think its "luck" that gives owners mileage past zero. Id call it an unplanned side effect of the complicated math. And depending on the factors, it can be quite substantial - I have drive 20 miles on a "0 miles left" battery.

Both of my Telsas will go quite far past zero. While that is a small sample size for sure, its still 100% my experience, and I would challenge anybody reporting anything otherwise; especially with the X or Performance Cars - you would have to be so incredibly soft with your driving to keep the algorithm from breaking... The mileage available is almost always off in its estimates due to the variables.

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Well that's good for you, but there are just as many anecdotal stories of cars dying with 15 or 20 miles still on the screen. The "complicated math" doesn't just err in your favor.

 

[apacheguy]

There are about a dozen threads on this already, but just briefly:

That picture does NOT come from Tesla. It is NOT accurate. THERE IS NO "ZERO MILE" PROTECTION BUFFER! There never has been. Tesla has denied it; it does not fit in with their marketing; it does not lend owners any benefits, and real-world experience shows it does not exist.

Some people luck out and go past zero because estimating zero is incredibly complicated (which is why this myth persists), not because there is a buffer. Many others have reported running out at or even a little before zero.

I totally agree with you regarding that graphic that has been circulated since day 1. It is most certainly not accurate.

However, my car does have a zero mile buffer. I have read this directly from the diagnostic screens and the BMS clearly shows 2-3 kWh below 0% UI SOC.

I do not mean to imply that all cars have this buffer.

 

[ChadS]

Interesting. Do the diagnostic screens differentiate between this buffer and the anti-bricking buffer? What kind of car do you have?

Many, many people have run out at exactly zero, and a few a little before, so this would be very curious.

 

[skilly]

Well that's good for you, but there are just as many anecdotal stories of cars dying with 15 or 20 miles still on the screen. The "complicated math" doesn't just err in your favor.

Has there been a poll is this your perspective? Be great to see some stats....running out of juice prior to your battery showing zero just shows the inaccuracy of the math predicting empty. Empty would be empty - I can understand it operating like a destination in navigation that changes in its ETA estimates, but out of juice is still out of juice. To me, something is wrong if you see range but your battery is dead.

The thing of it is, I suspect that its more accurate with cars that are easier to keep within the predictable ranges. For example, its easier to predict an S60 or S75 range and its accuracy vs. a PXXXD car.

 

[lymex2018]

I do believe "Zero Mile" Protection buffer exist, because the following reasons:

1. 'Tesla has denied it' is not true. There are two Tesla stuffs that told me so. Also see point 4 below.
2. Real world experience shows it does exist, I have deliberately done it twice.
3. "Many others have reported running out at or even a little before zero", this in my opinion is zero estimating error if these cases do exist.
4. The Tesla guy (on Bjorn's video at 0:03:25) explained that this 4kWh is the buffer below zero.
5. There exists many SOCs, one is the the SOC on the dash, when this SOC=0%, that called zero mile. However, there are other internal SOCs that show none zero/above zero value at this point.
There are two displayed on the Tesla diagnostic tool and they are larger than the dash:

When the battery is draining towards empty, other SOCs are about 4% to 6% larger than dash SOC. Below is the screenshot from Kmanauto's video (@islandbayy here) showing that SOC=4.0% when dash SOC is already zero:

 

[gearchruncher]

I just noticed something - @lymex2018 is in China. Is there any chance that Tesla manages capacities and ranges differently in different countries, and some of this is in the BMS? Tesla advertises the X as having 552 km of range in China, which is 342 miles! Maybe for some reason they give non-USA 4 kWh buffers on the battery and 0 in the US?

 

[verygreen]

I just noticed something - @lymex2018 is in China. Is there any chance that Tesla manages capacities and ranges differently in different countries, and some of this is in the BMS? Tesla advertises the X as having 552 km of range in China, which is 342 miles! Maybe for some reason they give non-USA 4 kWh buffers on the battery and 0 in the US?

you can switch to ideal miles in US too. No idea if there are rated km option in China, though.

 

[outie]

In the US it lists 295 mile range (EPA).

In China it shows 552km but who knows what's that based on?

 

[lymex2018]

I just noticed something - @lymex2018 is in China. Is there any chance that Tesla manages capacities and ranges differently in different countries, and some of this is in the BMS? Tesla advertises the X as having 552 km of range in China, which is 342 miles! Maybe for some reason they give non-USA 4 kWh buffers on the battery and 0 in the US?

Yes I'm in China, but as far as I've compared some videos on Youtube with mine, also the screen captures of TM-spy, I see no divination on the battery energy or SOC related numbers. Of course the range is different, but when they come to SOC=0% or below, all the ranges are the same. Zero mile, 0km or zero NEDC km, they are all zero, and these ranges stay 0 when the battery is drained further.

At first (before Dec. 2017), the range figure in China is NEDC rated, which is 565km for X 100D, but now must be GBxxxxx rated (a Chinese standard) so the figure becomes 552km. However when charged to full, my car is still display around 565km when set to ideal, or around 452km when set to typical (which is always 80% of ideal value).

 

[gearchruncher]

However when charged to full, my car is still display around 565km when set to ideal, or around 452km when set to typical (which is always 80% of ideal value).
View attachment 278412

452 km is 280 miles. In the USA, the 100D is rated at 295 miles. So it's rated 15 miles shorter in China than the USA.

In the USA, it's rated at 334 wh/mi (98.4 kWh) or 320 wh/mi (94.4 kWh)

In China, it's rated at 270 wh/mi (ideal) or 337 (rated), when using 94.4 kWh

Notice that the efficiency numbers for the USA at 98.4 and China at 94.4 are basically the same.

I still think the 4kWh difference that @lymex2018 is seeing may be due to them putting a different buffer in different countries.

 

[lymex2018]

452 km is 280 miles. In the USA, the 100D is rated at 295 miles. So it's rated 15 miles shorter in China than the USA.

In the USA, it's rated at 334 wh/mi (98.4 kWh) or 320 wh/mi (94.4 kWh)

In China, it's rated at 270 wh/mi (ideal) or 337 (rated), when using 94.4 kWh

Notice that the efficiency numbers for the USA at 98.4 and China at 94.4 are basically the same.

I still think the 4kWh difference that @lymex2018 is seeing may be due to them putting a different buffer in different countries.

Well, let's agree on one thing (or not):
a range, no matter what rated, refers to the distance driven when the dash SoC from 100% to 0%?

Also, is there any 100D owner in the US who also has Scan My Tesla so that we can check "Usable full pack"?

 

[skilly]

In the US it lists 295 mile range (EPA).

In China it shows 552km but who knows what's that based on?

uh....pretty sure that 345 mile range (552K/1.6) would be difficult to achieve on an incline with a tail wind for the entire duration.

 

[gearchruncher]

So I think Scan My Tesla has a bug.
I just ran it on my 90D with 11k miles. It shows 82.7 kWh as the pack size, and 78.7 kWh as usable after the buffer.

@wk057 looked at the fleet and says this:
"Average usable capacity for all ~65k "90" packs in the data: 81.3 kWh with an average odometer of only 11k miles."

My car has 12K miles. I really doubt that it has degraded that much, and the full charge mileage agrees, because I get 255 rated miles at full charge, which is only a few less than when it was new.

It appears Scan My Tesla under-reads by 4kWh.