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Wiki Sudden Loss Of Range With 2019.16.x Software
- Thread starter Dutchmeeuw
- Start date
Because entire bricks don't just die as others have previously said.
If a brick died, the whole car would die.
When a car loses 20 miles overnight, the BMS has decided to start limiting cell voltage for some reason (detected one of the conditions that wk075 has talked about), not that a brick has died.
It seems you just don't want to believe it, but I've been discussing this stuff with long time Model S owners since about 2013, and this is exactly what has happened to several of them. So it's fact.
Several of you keep arguing that this didn't happen because you are insisting that because they are set up in series, Tesla could not have possibly built in a method to deal with this type of failure, so there is no way around it. But apparently they do have some way to cut around or bypass each one somehow in the event that one of the bricks stops functioning in some way, and it's a good thing they do. I don't know what that method is, nor really care. I'm just helping people to understand that if they see that kind of symptom, it likely is this kind of battery pack physical problem that would require their pack to be taken out and worked on--not just estimation algorithms.
I'm simply describing how it shows up that the entire chunk of energy contained in it becomes unavailable to the car, as seen clearly in the display.
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If that is possible (clandestine ota updates) then that would add a new dimension to Tesla's 'behavior'. Without SMT data or similar it is hard to say. Same for @Rocky_H. Seeing 1 fewer bricks reported, or a 0 volt reading would end any further conjecture.
(But there is no circuitry for removing bricks from the battery. It would be like multiple main contactors in size. Very easy for a brick's worth of capacity to be made inaccessible though)
@Rocky_H, what difference does it make if you have lost 'what could be roughly 1 bricks capacity' or 'had a brick disconnected from your pack'? All that matters with regards to using the car is that your battery has lost capacity. In fact, how could you tell the difference between the two 'possible' causes?
In casual conversation I could totally accept the statement that 'the car lost 20 miles range because a cell / brick failed' without any implication that a brick had to have been 'disconnected'.
This ^^^ still makes sense and is doubtless the gist of what happens when a brick goes bad.
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It has been suggested that there are very very few cars in same situation as @Brass Guy with early software, but even so it would be great to see SMT or similar data for these cars.
Some 85 owners have said they have seen range (hopefully capacity too!) increasing recently, and it would be interesting to compare earlier software behavior with recent. One problem is that increasing charging times (for whatever reason - including lower ambient temperatures) could give weak cells longer to absorb and BMS longer to balance resulting in higher energy absorbtion = increased capacity / displayed range without any underlying 'fix' being applied.
Since the only way to protect 'failed / failing' cells would seem to be a combination of aggressive temperature control and voltage capping, it should be possible to spot any oddball behavior in cars still reporting pre-gate software.
Brass Guy
Active Member
I don't know about that. A friend of a friend is a local Tesla tech, and after asking to check something in the logs a while ago, the report back was that my VIN wasn't in the system any more. I thought it might have to do with the same thing that lost my connectivity; it might work both ways?
I might be able to test your theory by trying to supercharge this weekend and compare the rate.
Anything is possible, but you will know if it isn’t cell limiting, because the pack will decline rapidly(keep losing range). With cell limiting, you will be stuck with that same range loss for a long time.
I find it incredible that there is still no regulation of OTA updates - not even a published complete list of changes made (at least at a functional level) but the idea that car specs can basically be tweeked by Tesla at will and without my possible knowledge is a new level of unbelievable and unacceptable (if true).
Are there any owners logging subsystem software rev's on both (officially) updated cars and cars that have managed to avoid official updates?
BigNick
Infamous Fat Sweaty Guy
IF (that is a huge IF) Tesla can change the BMS without upgrading the rest of the software, that means the inverse should also be true: that the UI could be rolled back to v8 if someone had the skills to custom compile the software. Probably at the expense of the new features introduced in the last two years.
The lawsuit centers around the user visible OTA software updates. However, @swegman has reported in this thread of being told by Tesla that his BMS firmware was part of a 'test group' which he was previously not aware of:
Sudden Loss Of Range With 2019.16.x Software
Sudden Loss Of Range With 2019.16.x Software
Sudden Loss Of Range With 2019.16.x Software
Sudden Loss Of Range With 2019.16.x Software
It names "VIOLATION OF THE COMPUTER FRAUD AND ABUSE ACT(18 U.S.C. §1030 et seq.)" and "TRESPASS TO CHATTELS" which is hacking without permission. This covers everything they did, including clandestine BMS changes.
Brass Guy
Active Member
I arrived at the supercharger with around 50 miles remaining. Saw 118kw for a moment, then the usual drop to about 105kw. Charge rate was still 65kw at 50% when I left. No BMS update for me.
Also my report of range loss may be premature. If I divide my range by SOC I get 238; less than 5 mile drop. 90% was 202 Friday though.
BigNick
Infamous Fat Sweaty Guy
Started charging yesterday at 23% and got 84 kW rate, unpaired. Charged up to 70%, took between 3( and 40 minutes.
In the past I would get 115 kW when starting between 10% and 15%.
At another brand-new V3 SC, starting at 17% I saw a very brief 99 kW but within seconds it dropped into the 80s.
With only about 600 kWh total DC charging I wouldn’t think my SC should be throttled.
Battery was warm from highway driving before plugging in. I didn’t check the actual temperature however.
In the past I would get 115 kW when starting between 10% and 15%.
At another brand-new V3 SC, starting at 17% I saw a very brief 99 kW but within seconds it dropped into the 80s.
With only about 600 kWh total DC charging I wouldn’t think my SC should be throttled.
Battery was warm from highway driving before plugging in. I didn’t check the actual temperature however.
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