Infinite Mile Battery Warranty [Now] Being Honored By Tesla [Issue Resolved]

[dgatwood]

said who?

Says these guys. The official cycle life for 18650 batteries ends when the cells hit 80% of their original capacity. The fact that automakers' predatory warranty policies are designed to avoid repairing battery packs even when they are potentially operating in an unsafe state doesn't change the fact that the battery manufacturers consider them to be past the end of their life long before that.

- But even assuming that most of the Teslas with 200k+ miles have low range loss, so what? OP was unlucky, in the same way that my Honda van transmission broke at 90k miles, which is super rare for a Honda. Can I go demand that Honda fix it for free because it is super rare?

A transmission costs about $1,500 to repair. This costs $25,000 to repair. In terms of cost, this is more on the same order of magnitude as the front U-joint breaking, causing the axle to impale itself on the road and puncture the gas tank, resulting in the vehicle catching on fire. Also, the car in question had multiple drive motor replacements already. So even if this were really like a transmission, if your car at 250,000 miles had gone through two engines *and* the transmission, you would almost certainly never buy a Honda again. Tesla should really be bending over backwards to avoid getting sued over this one.

 

[Electroman]

Getting sued? OP should be sending a thank you note to Tesla for 200 miles range after 240k miles on the odo.

 

[dgatwood]

Getting sued? OP should be sending a thank you note to Tesla for 200 miles range after 240k miles on the odo.

With two motor replacements? Wow, you have some low expectations. That's bad even for Ford.

 

[Electroman]

Did OP pay for those two replacements? It was done under warranty.
In any cases how is that germane to this discussion of battery degradation?

 

[dhanson865]

The official cycle life for 18650 batteries ends when the cells hit 80% of their original capacity.

Which is great for a laptop or other consumer device that stays indoors mostly. Totally unrealistic for a car battery in Texas heat to be held to the same standard as a laptop battery in an air conditioned office building.

 

[dgatwood]

Did OP pay for those two replacements? It was done under warranty.
In any cases how is that germane to this discussion of battery degradation?

Whether the warranty covered them is irrelevant. Those other major failures are an indication of how bad an experience the vehicle has been for its owner. Three or more catastrophic failures in just a few years qualifies as an incredibly bad overall experience.

Most companies factor in the history of a product, and if a product has been particularly bad, they are much more amenable to repairs, because companies that don't do that tend to lose customers. Besides the individual customers themselves, you also get threads like this one that begin with someone ranting about their car after having experienced an absolutely absurd number of major failures. Threads like this tarnish the brand's reputation, which in the long run is far more expensive than doing a few extra battery refurbs for customers whose cars were obvious lemons.

 

[dgatwood]

Which is great for a laptop or other consumer device that stays indoors mostly. Totally unrealistic for a car battery in Texas heat to be held to the same standard as a laptop battery in an air conditioned office building.

Worn out is worn out. When the battery gets below a certain level of charge, it starts to misbehave very badly, sometimes even resulting in fire. Those recommendations exist for a reason, and it is even more important in a car with a huge pack than in a tiny laptop battery in an air-conditioned building, precisely because the car battery has to avoid catastrophically failing under much higher current draw and in potentially much worse thermal conditions.

 

[dhanson865]

When the battery gets below a certain level of charge, it starts to misbehave very badly, sometimes even resulting in fire

gee, don't you think that's why battery controllers shut down devices before the voltage gets that low? Degradation isn't about state of charge, its about usable capacity reduction.

on top of that the 80% you quoted from that website is cell percent not in car usable capacity percent. As in Panasonic might rate the cell for x capacity, Tesla bundles thousands of cells into a pack and has reserve capacity excluded from the usable capacity. Thus the percentages are on a different scale.

So if you want to pull up TMspy numbers and compare those, fine. Internal numbers on the pack would be good to look at. But if you are just going by dash numbers and how far someone drives then you don't know what the internal numbers are.

 

[dgatwood]

gee, don't you think that's why battery controllers shut down devices before the voltage gets that low? Degradation isn't about state of charge, its about usable capacity reduction.

Battery controllers cannot prevent fires. Dendrites have nothing to do with going below the threshold voltage. Discharging below the low-voltage threshold does cause chemical changes in batteries that permanently reduce its capacity, but this has nothing whatsoever to do with dendrite growth, which is a side effect of charge-discharge cycles, and can vary significantly from cell to cell.

When dendrites happen, they can dramatically reduce the capacity of a battery in ways that often cause sudden voltage drops during discharge. If you continue using a cell in that state, one day, one of those dendrites will grow enough to reach the cathode, and then bang. Game over.

I'm not saying that this has occurred in the battery in question, because I have not taken apart the pack and taken X-rays of all of the cells. It is also possible that the battery controller simply has no idea how to determine the remaining capacity of the cells in the pack because they are so far beyond the lifespan for which the cell manufacturers provide data, and therefore isn't limiting engine power enough. Either of those is problematic, of course, but only one of those two possibilities is likely dangerous. My concern is that as far as I know, there's no real way to be certain which theory is correct (short of X-rays, that is).

But the reason I'm so concerned is that Tesla made a claim three years ago that they were working on a firmware fix that would prevent premature shutdowns on high-mileage packs. I can't imagine that they haven't figured out the charge-cycle-to-low-voltage-capacity calibration curve by now. That strongly suggests that this pack is behaving significantly outside of the expected parameters for its cycle count, which makes it much more likely that the problem is, in fact, something serious.

on top of that the 80% you quoted from that website is cell percent not in car usable capacity percent. As in Panasonic might rate the cell for x capacity, Tesla bundles thousands of cells into a pack and has reserve capacity excluded from the usable capacity. Thus the percentages are on a different scale.

Actually, you're doing the math backwards. Suppose you have a pack that is rated for 100 miles, but it has a hidden 20% capacity, so that it can continue to degrade and still report full capacity. Now suppose that it is actually only providing 80 miles of range. That means it is at 80/120ths of its capacity, which is a 25% capacity loss, rather than the 20% implied by the percentage of the official rated range for the car.

So if the percentages are on a different scale, then the batteries are likely even further outside of manufacturer recommendations than the numbers would imply, and I'm even more concerned.

 

[dhanson865]

Actually, you're doing the math backwards. Suppose you have a pack that is rated for 100 miles, but it has a hidden 20% capacity, so that it can continue to degrade and still report full capacity. Now suppose that it is actually only providing 80 miles of range. That means it is at 80/120ths of its capacity, which is a 25% capacity loss, rather than the 20% implied by the percentage of the official rated range for the car.

no, it only means the dash says that is the range available. You have to use something like TMspy to see the internal numbers. Any hand waving math about range shown by the dash is irrelevant when talking about capacity to the point of actual health of individual cells. I did no math forwards or backwards because we don't have internal pack data to discuss.

I'll give you a hint that the relationship doesn't have to be linear. The dash data vs the internal pack data can be higher or lower on either side of the equation and doesn't have to maintain any sort of ratio.

Your concern about dendrites sounds like you've read up a little on the subject. Your lack of knowledge of how a car manages a battery pack leaves me thinking we've hit a gap in your understanding on how it all fits together. I'll leave this for someone else to explain to you if you still want to discuss it here.

 

[Jax3]

I HAVE BEEN A LOYAL TESLA OWNER SINCE 2013. MY FAMILY CURRENTLY OWNS A 2012 TESLA MODEL S 85, 2016 TESLA MODEL X 90 AND JUST MOST RECENTLY PURCHASED A 2018 MODEL S 100. THE MOST IMPORTANT REASON WE CONTINUE TO PURCHASE FROM TESLA IS THE INFINITE MILE BATTERY AND POWER TRAIN WARRANTY. MY 2012 TESLA MODEL S WAS PURCHASED IN 2013 AND THEREFORE THE WARRANTY DOESN'T EXPIRE UNTIL 2021. TESLA HAS REPLACED THE POWER TRAIN 3 DIFFERENT TIMES SINCE 2013 FOR THE MODEL S WITHOUT ANY PROBLEMS IN HONORING THE WARRANTY. IN JANUARY OF 2019 WE BROKE DOWN ON THE SIDE OF THE HIGHWAY WITH 16 MILES LEFT ON THE RANGE INDICATOR AND ONLY 139 MILES ON THE CURRENT TRIP BEING TAKING. THE ONLY WARNING THE CAR GAVE ME AT THAT TIME WAS "BATTERY VERY LOW, NEEDS CHARGING" ONCE WE HAD BROKE DOWN. I HAD BEEN HAVING PROBLEMS FOR YEARS WITH THE DECREASING BATTERY RANGE AND TESLA JUST SAYING IT IS DEGRADATION OR THE WAY I DRIVE IT. I DRIVE ALL OF THE VEHICLES THE SAME. THE ONLY DIFFERENCE IS THE AMOUNT OF MILES THE 2012 ACTUALLY GETS WHEN DRIVING. THE BATTERY CAPACITY WAS GETTING AROUND 175 MILES PER TRIP CHARGE BEFORE THE MOST RECENT BREAK DOWN. TESLA IS NOT WAVERING ON NOT REPLACING THE BATTERY. THE HOUSTON NORTH SERVICE CENTER ACTUALLY RESPONDED THAT THE WARRANTY CLEARLY STATES DEGRADATION ISN'T COVERED. MY ARGUMENT WAS THIS IS CLEARLY MORE THAN DEGRADATION BUT THEY SAID THIS IS WHAT UPPER MANAGEMENT HAS TOLD ME TO SAY. I TOLD THEM THAT I HAVE READ IN OTHER ARTICLES THAT BATTERIES HAVE BEEN REPLACED FOR THE SAME ISSUES THAT I AM HAVING BUT THE RESPONSE I GOT WAS STILL THEY WOULD NOT REPLACE THE BATTERY. I ASKED HOW LOW THE BATTERY HAS TO GET FOR THEM TO HONOR THE WARRANTY AND THE RESPONSE I GOT WAS IF IT ISN'T A HARDWARE ISSUE THAT THEY WOULDN'T REPLACE THE BATTERY. I RESPONDED BY SAYING SO THE CAR COULD GET DOWN TO 50 MILES OF BATTERY RANGE AND YOU COULD SAY IT IS JUST DEGRADATION. THE RESPONSE WAS YES. I DESPERATELY WOULD APPRECIATE ANY SUGGESTIONS TO GET TESLA TO HONOR THE WARRANTY AND TO WARN OTHERS ABOUT TESLA'S NEW POLICY ON BATTERY REPLACEMENT.

SHOUTING is good for a word or, at max, a sentence. If you insist on writing more in caps, many of us simply move to something else. My eyes don't like reading all caps regardless of the message.

 

[2012MS85]

SHOUTING is good for a word or, at max, a sentence. If you insist on writing more in caps, many of us simply move to something else. My eyes don't like reading all caps regardless of the message.

Easy on the OP; he stopped shouting days ago And he’s been very polite ever since

 

[David_Cary]

A driveunit failure is not a "catastrophic failure" - most of the time. That kind of hyperbole diminishes other parts of someone's arguments. There was a known issue with driveunits. It is why we have the unlimited warranty. The original purchase in 2012 or 2013 did not have an unlimited driveunit warranty. It was changed because of the common problem that has by all accounts been fixed. The vast majority of replacements were due to noise (and that was a precursor to failure).

This is not comparable to a Honda van transmission. BTW - for many years, Honda put the same tranny in the Accord and the Odyssey and the Odyssey had a large number of modest mileage failures - 50k was common. Out of warranty. The Odyssey was probably too heavy for that tranny. So nothing unusual about an Odyssey tranny failure.

I have to laugh at someone in Orange county claiming to have the same climate as Houston.

Tesla should really have an option for high mileage replacements at their cost. We all know that $25k is the replacement cost from insurance claims and that is reasonable. But having some kind of prorated replacement for degradation in high mileage situations would be reasonable. There will be more of this in the next few years. It would be nice if at 7 years and 250k miles, one could get a $12k battery which is probably their cost.

I have a 2013 Leaf. On the forums back in the AZ heat issue days, batteries did funky things when degradation hit significantly. They had modules and 1 weaker module would raise internal resistance and get hot. That heat would make it degrade even faster. This all confuses the BMS. Obviously Tesla batteries are a different chemistry and have better cooling. But the reality is that cells will degrade at different rates. Once you hit a decent difference between cells, the degradation accelerates quickly - even exponentially. Not always but usually when there is accelerated degradation. There is someone out there with a 50% degraded Leaf that keeps on trucking but that isn't the usual case.

I don't think we know what happens to individual cells in high mileage cases. Are some of your cells at zero? Can that happen? I know there are people on this forum who understand how many cells are in series - I guess it would be 250 or so (400V divided by 1.5) Then do cell blocks fail 250 at a time when a single cell fails?

Did Tesla ever claim to have a fix for high mileage range estimating? They replaced that battery and said they would update the software. I can't say I have high confidence that they were able to fix it.

 

[HMARTINPT]

A 25% capacity loss falls under the category of "failed" by normal industry standards. Typical degradation for Tesla packs should be, on average, more like 10% loss after 500k miles, statistically speaking. A 25% theoretical range loss after half as many miles is about 5 times the average rate of degradation. That does not sound normal to me.

Also, if the "10 miles remaining" estimate was accurate on the previous trip, then the vehicle lost about 25 miles of range in three months. At that rate of decline, the pack probably won't last much longer no matter what you do, and it's only a matter of time before it starts shutting down at a higher and higher SoC.

If you want to maximize the chances of getting a free replacement (albeit at some personal risk), your best bet would be to charge to 100% every time, drive as aggressively as possible, and run the battery down as low as you can every time, making Tesla tow you every time it runs out before it hits zero. I'd say you have a high probability of the pack completely failing to take a charge long before the warranty runs out if you do that. Even better, at up to $250 per tow, if you can manage to reproduce the failure once per week, it will cost Tesla more in towing than it would have cost them to replace the battery.

That said, I would worry about whether the pack is even safe to use at this point. After all, a vehicle experiencing a sudden shutdown 10+ miles before it was expected to run out of battery strongly implies a sudden voltage drop under load, and in Lithium ion cells, sudden voltage sags frequently indicates dendrite growth, which can cause localized overheating and venting with flame. So when I say "albeit at some personal risk", I'm not kidding. If this were my car, I would refuse to take possession of any vehicle that experienced any sort of sudden shutdown above zero miles of reported range unless the manufacturer provided certification in writing that the pack did not pose an elevated risk of fire.




If you haven't already, please file a NHTSA complaint and report the problem in detail. Vehicles shutting down in the middle of the highway are potentially very dangerous in and of themselves. And if the battery later fails catastrophically, then a NHTSA complaint will make it obvious that Tesla was aware of the problem and behaved negligently, which will substantially increase the resulting damage award.

That was very informative and put a new insight on how to handle this problem. This is why I came to this sight to try and figure out a way to resolve this problem with Tesla. I will go ahead and do the NHTSA complaint. If I go up in flames one day I will have a bunch of witnesses on this site although by some of the responses I have received some would like to see me burn.
By the way I did do a trip charge @ 100% last night and it has already dropped from the quoted "212" from Tesla to 200. That is a drop of 12 miles in just 2 days. I wish Tesla would just do the right thing like they have done in the past. Thanks for your input!

 

[HMARTINPT]

said who?

couple of things:

- You are extrapolating the low capacity loss for a small number of known 100k to 150k mile cars

- There have been very few known Teslas that have this much mileage, and sure they did not have 25% range loss. But those datapoints are so small to make any conclusion.

- But even assuming that most of the Teslas with 200k+ miles have low range loss, so what? OP was unlucky, in the same way that my Honda van transmission broke at 90k miles, which is super rare for a Honda. Can I go demand that Honda fix it for free because it is super rare?

Note: I added the bold &italics words in your quote to give the full context for that sentence.

Yes you could if Honda had an 8 year/infinite mile warranty. Once again the warranty is the primary reason we have purchased 3 Tesla's. If Tesla doesn't want to honor that they shouldn't keep on promoting 8 year/infinite mile warranty on the battery and drive unit.

 

[Bostoniannu]

The all caps is just painful to read.

 

[HMARTINPT]

Battery controllers cannot prevent fires. Dendrites have nothing to do with going below the threshold voltage. Discharging below the low-voltage threshold does cause chemical changes in batteries that permanently reduce its capacity, but this has nothing whatsoever to do with dendrite growth, which is a side effect of charge-discharge cycles, and can vary significantly from cell to cell.

When dendrites happen, they can dramatically reduce the capacity of a battery in ways that often cause sudden voltage drops during discharge. If you continue using a cell in that state, one day, one of those dendrites will grow enough to reach the cathode, and then bang. Game over.

I'm not saying that this has occurred in the battery in question, because I have not taken apart the pack and taken X-rays of all of the cells. It is also possible that the battery controller simply has no idea how to determine the remaining capacity of the cells in the pack because they are so far beyond the lifespan for which the cell manufacturers provide data, and therefore isn't limiting engine power enough. Either of those is problematic, of course, but only one of those two possibilities is likely dangerous. My concern is that as far as I know, there's no real way to be certain which theory is correct (short of X-rays, that is).

But the reason I'm so concerned is that Tesla made a claim three years ago that they were working on a firmware fix that would prevent premature shutdowns on high-mileage packs. I can't imagine that they haven't figured out the charge-cycle-to-low-voltage-capacity calibration curve by now. That strongly suggests that this pack is behaving significantly outside of the expected parameters for its cycle count, which makes it much more likely that the problem is, in fact, something serious.



Actually, you're doing the math backwards. Suppose you have a pack that is rated for 100 miles, but it has a hidden 20% capacity, so that it can continue to degrade and still report full capacity. Now suppose that it is actually only providing 80 miles of range. That means it is at 80/120ths of its capacity, which is a 25% capacity loss, rather than the 20% implied by the percentage of the official rated range for the car.

So if the percentages are on a different scale, then the batteries are likely even further outside of manufacturer recommendations than the numbers would imply, and I'm even more concerned.

Thanks for your very informative lesson. I should hire you instead of a lawyer if it comes to that. You are making me very nervous now about the dendrites growing enough to reach the cathode. I don't want to ever hear the BANG.
Please help me with this question. I supercharged yesterday because I didn't want to come anywhere close to going under 10%. When the vehicle was at the supercharger it began to get louder and rattle more than ever before. I got to the point where I got out of the vehicle because I was afraid of a "bang". I have SC quite a bit in my day but nothing like this. Any suggestions on what could be going on? Thanks again for you input!

 

[mongo]

Thanks for your very informative lesson. I should hire you instead of a lawyer if it comes to that. You are making me very nervous now about the dendrites growing enough to reach the cathode. I don't want to ever hear the BANG.
Please help me with this question. I supercharged yesterday because I didn't want to come anywhere close to going under 10%. When the vehicle was at the supercharger it began to get louder and rattle more than ever before. I got to the point where I got out of the vehicle because I was afraid of a "bang". I have SC quite a bit in my day but nothing like this. Any suggestions on what could be going on? Thanks again for you input!

Possibly the air conditioning compressor increasing to cool the pack. I think there were some noise reduction adjustments they did on the early cars for it (also an issue where the high and low pressure lines were installed backwards).

In the event of a dendrite, you would likely not get a big BANG. The short through the whisker would just be vaporized by the current. If a cell had a continuous short, it would either heat and drain the brick (causing the pack to fail) and possibly vent, or be a good enough conductor to blow the fuse on the cell.
Remember, each cell is in a steel can, inside a plastic module, inside an aluminum housing with vents in case of a catastrophic failure.

 

[HMARTINPT]

Possibly the air conditioning compressor increasing to cool the pack. I think there were some noise reduction adjustments they did on the early cars for it (also an issue where the high and low pressure lines were installed backwards).

In the event of a dendrite, you would likely not get a big BANG. The short through the whisker would just be vaporized by the current. If a cell had a continuous short, it would either heat and drain the brick (causing the pack to fail) and possibly vent, or be a good enough conductor to blow the fuse on the cell.
Remember, each cell is in a steel can, inside a plastic module, inside an aluminum housing with vents in case of a catastrophic failure.

OK. Thanks. That makes me feel much better!

 

[ricohman]

240k mile ICE car that runs great and is great for long distance driving is an exception and not the norm.

My old beater Focus has 340,000 kms. My FJ40 over 500,000 miles. Yes miles.
My old SD Ford had 380,000 when I sold it.