Wiki Sudden Loss Of Range With 2019.16.x Software

[Droschke]

They did not. The techs were very understanding of my desire not to have it messed with. After the intake guy didn't understand what was going on, he went in and got the head tech to come out to understand what was going on. He explained that since it was only a screen replacement, it would be replaced under warranty without the need to update my software... because I don't have to update my software to keep the warranty. No more bubbles! I talked to them about some other stuff in the car that would be messed up if they updated (comma OP), and the tech knew what it was and understood that I didn't want it broken. So all in all a good visit. I was treated well by the Nashville, SC. The people on the ground are pretty nice, everyone in the store and at the SC are super nice. Seems it's just the corporate overlords who are making this range capping thing an issue.

Thanks for the feedback. The SC customer care quality varies. Glad yours are nice even without buying doughnuts.

 

[meomyo]

I took in the model 3 today and went over the CAC test results with the Tesla rep for my model S.

I don’t want to get into great detail about the test results because I don’t want anyone to possibly get in trouble (I was requested not to photograph the computer screens or to write notes of what I reviewed). Suffice it to say, I was disappointed by what the CAC test report shows (or more accurately, doesn’t show).

Basically, my battery is shown as being way better than the same type battery out there (same age and mileage). In fact, numerous CAC tests were performed over the past several months, with each subsequent test showing the battery in my car being “more better” than the comparison batteries in the previous test.

Based on the Ah result of the CAC tests (which was the same on every test), my battery has a capacity of about 75.7 kWh. However, my battery is currently capped at 68-69 kWh.

The Tesla rep has no explanation for why my car is capped, other than I am part of a test group. He is unable to tell me whether there is any problem with my battery that resulted in the capping (he said Tesla operates like the military and only tells him what they deem he needs to know). He indicated that the BMS firmware on my car is unique, he has not seen my version on any other car in his coverage area. He insists I will eventually get an update that will likely uncap the battery, but there are no updates pending for my car at this time. I informed him that my car is not connected to WiFi, and he said it doesn’t matter, his system would show if there is an update available for my car and if I had no WiFi the update would be sent via LTE. I can vouch that I have received numerous updates via LTE only for at least the past 3 years.

As an aside, their log shows exactly what firmware versions have been available for my car, which ones were installed (and when) and which ones (if any) are available to be downloaded and installed. I never had an update fail to install, so I’m not certain if their records would show failed installs.

As to how each subsequent CAC test shows my battery to be better than the “general battery population” by a greater amount while the Ah of my battery remains unchanged, I can only conclude that it means that the general battery population is getting worse (maybe more batteries are being capped). What I mean is, say there are 10 batteries of my age and mileage in a comparison group and only my battery is capped. My battery would show as being worse than the general battery population. Now over time, the other batteries get capped to a level lower than mine. Although my battery remains exactly like it was in the first CAC test, the second CAC test will show my battery to be better than the general battery population. So being told your battery is 10%, 20%, 30% or whatever better than other batteries in the comparison group tells you nothing unless you are also told whether the other batteries are also capped. In this regard, another Tesla rep told me that the new policy for model S battery replacement is that your battery must be more than 30% below the average battery of the same age and mileage. The more cars Tesla caps, the lower the range the average battery in the comparison group will have, and thus, the more difficult it becomes to qualify for a replacement battery.

I asked about requesting that a Tesla remove the cap on my car. The Tesla rep said it is not going to happen until such time as Tesla decides they want to remove the cap or they are ordered to do so by a court.

Incidentally, I was given a model S car as a loaner. The trunk of the car indicates it is a P85. However, the touchscreen says it is a P90. At an 81% charge level, the loaner has an indicated range of 220 miles, whereas my 81% range is approximately 188 miles.

hm...so who owns the car tesla or you(the person who bought it?)

 

[raphy3]

The Tesla rep has no explanation for why my car is capped, other than I am part of a test group.

I asked about requesting that a Tesla remove the cap on my car. The Tesla rep said it is not going to happen until such time as Tesla decides they want to remove the cap or they are ordered to do so by a court.

Wait, so, someone at Tesla told you that you're a guinea pig? It would be interesting if you can get that in writing. That combined with the second part "they won't remove until compelled by court" makes it sound like you are literally being forced to participate in a test you didn't consent to being part of. That just doesn't sounds right (or legal). I wonder if the reps don't know what they're talking about.... This is a symptom of Tesla's communications problem.

 

[Droschke]

Wait, so, someone at Tesla told you that you're a guinea pig? It would be interesting if you can get that in writing. That combined with the second part "they won't remove until compelled by court" makes it sound like you are literally being forced to participate in a test you didn't consent to being part of. That just doesn't sounds right (or legal). I wonder if the reps don't know what they're talking about.... This is a symptom of Tesla's communications problem.

I won't be surprised if in fact the rep is correct. The whole ownership experience is so many ways looks like being part of a test group. Take the software update deployment scheme for example. Each time, we are all part of a test group for Tesla till Tesla gets all these buggy updates right. IIRC, I think @swegman is the 2nd owner who is told they are part of a test group.

 

[MikeyC]

We know Tesla thinks they can fix everything with "data", so maybe when the test period is over, there will be a prompt on the car's display:

Please pick the closest answer...

My car is:

1. Still driveable
2. Burned beyond recognition

If no one taps #2, they'll know everything is fine.



Mike

 

[MP3Mike]

Capping has zero to do with the battery CAC.

You're saying that the capping can't possibly impact the testing procedure or results?

 

[SBK2013]

I'll add a theory to this thread. I think they may have also increased the software's sensitivity to battery issues. I recieved a warning last week "Acceleration Decreased" and a note to see a service center. My car a 2013 Model S 60 with 115K miles on it) is there now, and I was just informed they are replacing the battery. I assume the found a problem, I just can't help but wonder if the new software also has a lower threshhold before it flags a battery problem.

Anyone else see this Acceleration Decreased notification on their car?

 

[raphy3]

I'll add a theory to this thread. I think they may have also increased the software's sensitivity to battery issues. I recieved a warning last week "Acceleration Decreased" and a note to see a service center. My car a 2013 Model S 60 with 115K miles on it) is there now, and I was just informed they are replacing the battery. I assume the found a problem, I just can't help but wonder if the new software also has a lower threshhold before it flags a battery problem.

Anyone else see this Acceleration Decreased notification on their car?

I haven't, but know some others who had the exact same error message. They had 100kW of power to get to the SC.... Turned out to be contactors in that case.

 

[qwk]

You're saying that the capping can't possibly impact the testing procedure or results?

There is no testing procedure. The SC reads the numbers off of the diagnostic screen, like the one posted last page. When the battery is super cold, the numbers are lower, but not by much.

 

[MP3Mike]

There is no testing procedure. The SC reads the numbers off of the diagnostic screen, like the one posted last page. When the battery is super cold, the numbers are lower, but not by much.

And where does the number come from? How is it calculated? Unless you know that you can't know that the capping didn't impact the results.

 

[swegman]

I guess another option is that their CAC test doesn't work properly on capped batteries.

The CAC test determines the full capacity of the battery as if it is not capped. Based on the CAC test, my battery has a capacity of about 75.7 kWh, but Tesla has capped it so that only 68 kWh are useable.

 

[swegman]

I was told a new 85 kWh battery has a rating of 230 Ah. Each CAC test (performed over a 2-1/2 month period indicated my car’s battery has a CAC rating of 219 Ah, which corresponds to a little less than a 5% capacity degradation over 6+ years. However the range of my car has decreased by about 10.7% (the car previously charged to 253 miles at 100% charge the day before the forced update occurred, but now the car only charges to 226 miles at 98% (the car no longer charges to 100%)).

The “full” charge after the forced update corresponds to the 89% charge level of the pre-forced update In other words, Tesla took away 11% of the car’s battery range with its capping update.

 

[swegman]

hm...so who owns the car tesla or you(the person who bought it?)

Sorry, I don’t understand your question. The CAC tests were performed on my Model S car’s battery.

 

[DaveBC]

There is no testing procedure. The SC reads the numbers off of the diagnostic screen, like the one posted last page. When the battery is super cold, the numbers are lower, but not by much.

I’ve wondered about this since the CAC test was mentioned long ago on the thread. I know the CAC (calculated amp-hour capacity) is a value calculated by the BMS and can be read in toolbox or the diagnostic screen.

I wasn’t sure if the service centre did some sort of procedure before taking note of what the vehicle tells them. I imagined a discharge/charge cycle to specific SoC levels. Otherwise it hardly seems like much of a test, you’d think the value could just be polled remotely.

Maybe they found people with battery health concerns were satisfied with a diagnostic procedure that required a service centre visit. Satisfied for the most part until May of 2019, strangely.

 

[swegman]

Wait, so, someone at Tesla told you that you're a guinea pig?

No, I was told (several times) that my car was selected to be part of a test group to test a revised BMS firmware.

Tesla routinely release updates to a small group of people before doing a full-wide release.

 

[swegman]

I’ve wondered about this since the CAC test was mentioned long ago on the thread. I know the CAC (calculated amp-hour capacity) is a value calculated by the BMS and can be read in toolbox or the diagnostic screen.

I wasn’t sure if the service centre did some sort of procedure before taking note of what the vehicle tells them. I imagined a discharge/charge cycle to specific SoC levels. Otherwise it hardly seems like much of a test, you’d think the value could just be polled remotely.

Maybe they found people with battery health concerns were satisfied with a diagnostic procedure that required a service centre visit. Satisfied for the most part until May of 2019, strangely.

I was told that with the Roadster the SC had to have access to the car to download the data into a flash drive plugged into the car’s USB port, but that with the Model S, X and 3, the data is retrieved via the car’s telemetry connection.

 

[jaitch]

This was shown by tapping on the Tesla logo at the top center with Developer mode enabled. It displays detailed configuration data.

2019.16.3

How do we get Developer Mode? Isn't this a Tesla service tool feature that no layman can access? I thought it was only accessible with the right software tools and the correct daily password or something or other. You mention it like we can all check it if we want?

James

 

[Droschke]

I was told a new 85 kWh battery has a rating of 230 Ah. Each CAC test (performed over a 2-1/2 month period indicated my car’s battery has a CAC rating of 219 Ah, which corresponds to a little less than a 5% capacity degradation over 6+ years. However the range of my car has decreased by about 10.7% (the car previously charged to 253 miles at 100% charge the day before the forced update occurred, but now the car only charges to 226 miles at 98% (the car no longer charges to 100%)).

The “full” charge after the forced update corresponds to the 89% charge level of the pre-forced update In other words, Tesla took away 11% of the car’s battery range with its capping update.

We are calling it a CAC test. But, is this CAC really a test where they run a routine on the car for several minutes/hours, or like @qwk said it's just reading the data already stored on the car and displayed on the diagnostic screen they have access to?

 

[3ry-reset]

We are calling it a CAC test. But, is this CAC really a test where they run a routine on the car for several minutes/hours, or like @qwk said it's just reading the data already stored on the car and displayed on the diagnostic screen they have access to?

CAC is always calculated by your car. You see it in my photo I posted and all I did there was open the door, enable dev mode, and take the picture. It took 3 minutes at most and I didn't know CAC would be shown so I didn't calculate it. @jaitch Dev mode either needs your service center or root. If someone with a limited battery can ask someone for temporary root, they can take a picture of that screen and show what I think will be 80% value for the soft cap and UI cap. A factory limited 40 or 60 owner will probably show the low % on cap & UI.

 

[3ry-reset]

Tesla says they don't accept third party apps but dev mode is 1st party