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Wiki Sudden Loss Of Range With 2019.16.x Software
- Thread starter Dutchmeeuw
- Start date
If someone with the limit has root, can you check Developer Mode under the Data tabs BMS section?
Look at the "Software full pack energy" and compare it to the "nominal full pack energy."
Also look for the "Soft pack energy limit" and "UI Energy limit" lines to see if these are reduced to less than 100%.
This could be the smoking gun?
Look at the "Software full pack energy" and compare it to the "nominal full pack energy."
Also look for the "Soft pack energy limit" and "UI Energy limit" lines to see if these are reduced to less than 100%.
This could be the smoking gun?
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.
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.
They need to compare the software full pack energy to other cars, not the CAC. The software limited cars still show a great CAC number. If you can’t use the full pack, a good CAC does absolutely nothing.
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
Thanks for a very informative post. Few observations/questions:
What is your CAC score?
"more better" CAC score, but you are still capped! Go figure.
How one distinguishes that. All I know is the software update level. Is there a seprate BMS level within that SW update level?
Very interesting. One almost needs to look at all this forensically.
That would be my understanding as well.
That has been my concern all along too.
Thanks for this tip. Otherwise it would be very deceiving.
Of course this is not in writing, but isn't this what @DJRas's understanding of it also is?
What is your CAC score?
"more better" CAC score, but you are still capped! Go figure.
How one distinguishes that. All I know is the software update level. Is there a seprate BMS level within that SW update level?
Very interesting. One almost needs to look at all this forensically.
That would be my understanding as well.
That has been my concern all along too.
Thanks for this tip. Otherwise it would be very deceiving.
Of course this is not in writing, but isn't this what @DJRas's understanding of it also is?
.
Answer- I believe so. But it appears to be a moving target since the capacity of the general population batteries appears to be decreasing with time (at least that is my conclusion based on the results of multiple CAC tests, with each test showing my battery to be better than the general population by an increasing percentage. The Tesla person that told me about the change in policy basically told me that unless the battery totally fails, one is unlikely to get a replacement under the new policy.
Say the average range of your comparison group at test 1 is 200 miles at 100% charge. You won’t get a replacement of your battery unless your range is less than 140 miles. Now, 2 month later you get a second test and this time the average range of your comparison group is say 180 miles. This means your battery must have a range of no more than 126 miles to qualify for a replacement battery. Two months later you get a third test but this time the range of the comparison group is 170 miles, so now your battery can have a range of no more than 119 to qualify for a replacement battery. It seems, based on the test results I saw, that one is chasing an ever decreasing average range in your comparison group (meaning other batteries of similar age and mileage to your battery).
Or what it means is that the non-capped batteries have been degrading while your capped battery has been protected from excessive degradation. So they are getting worse while yours is staying the same.
cpa
Active Member
This might be exactly what is happening. Tesla wants us all to show degradation such that they will rarely, if ever, have to replace a battery until we have to pay for one.
Thanks. Very informative. Their policy is designed on purpose to be a moving target. In absence of a failure (a bricked battery for example), there is no hope to get battery replaced under their 30% degradation policy during the warranty period. Very clever for them, very bad for the owners.
Technically that policy is way better than the warranty. It gives you a chance, slim as it is, to get a replacement for degradation.
Yes, I see your point. But we are talking about the difference between no policy and a policy that sets the threshold too high which makes it impossible chance (you say slim chance) to benefit from. It's basically the same thing. As I said, very clever of them.
I guess another option is that their CAC test doesn't work properly on capped batteries.
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.
Capping has zero to do with the battery CAC.
Capping is kind of like the 85 mph loaner limit, while the CAC is more like the actual cars speed limit(varies by car).
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