Wiki Sudden Loss Of Range With 2019.16.x Software

[doctorwho]

The Remote S (now called Tesla Remote) app allows you to set the charge percentage in 1% increments. Tesla defined (at least when I originally bought the car, and maybe still) a 90% to 100% charge as being for trips and that charging up to these levels should not be done on a regular basis. Thus I set my charge rate to 89%, which is within Tesla’s preferred daily charge level.

Well, that's the trouble, I regularly have a long commute, I used to charge to 80%, now, with reduced capacity, I have to charge to 90% to go the same distance. Here's my battery capacity graph from Teslafi. The rise is after a 100% charge that maybe just recalibrated rather than increased the capacity. I'm still on 2019.28.2.5 f5ae58a

 

[egn1]

IMHO the changes Tesla has made are all connected to the same problem - lithium plating and the consequence - growing of dendrites.

First of all, lithium plating is caused by lithium ions, that cannot intercalate into the crystal lattice of the graphite anode fast enough. Intercalation rate is dependent on temperature. The higher the temperature the more room is for lithium ions.

All owners have noticed that the charging rate at cold temperatures was continuously reduced after the last several years by Tesla. A few years ago it was no problem to get charge rates above 100 kW in winter. But last winter the charge rate dropped very often below 50 kW, if there wasn't a longer high power drive before the stop. For me this is an indication that Tesla has noticed that to high charge rate at to low temperature has negative impact on lifetime. They tried to fix that only for winter time, but noticed that even in summer the charge rate was to high to prevent lithium plating.

So Tesla chose to go all-in and connect current charge rate directly to current battery temperature. In order to reduce the impact, they actively heat the battery on the way to SuCs charging to reduce the impact regarding charge time. But heating takes some time and uses up more energy, that can be recovered only partly because of better charge efficiency of a warm battery.

The strategy regarding temperature and charging seems to be:

Up to a certain SOC (80? %) they try to keep cell temperature in the range between about 40° C (104 F) and 45° C (113 F). This achieves maximum intercalation rate.

They put in a hard stop regarding maximum voltage when detecting a increased dV/dt, which indicates that intercalation rate is slowing down and further lithium plating is risked. To detect this with high accuracy a slow charge rate is better. So they reduced the charge rate above 80 % or above a specific voltage drastically.

The problem with lithium plating is that it is kind of exponential process, because more and more paths to free intercalation volume is clogged by the metallic lithium.

As already mentioned, regarding newer cells of 90+ kWh and M3 batteries, the silicon helps, because with silicon there is no intercalation, but conversion with much higher density. So it is save at this point. But as can be seen with the 90 kWh battery, to much silicon has other negative side-effects, which also limits charging rate.

I have still mixed feelings whether this is covered by the warranty:

On one side all this is part of natural degradation of lithium cells used within manufacturer specification.

On the other side tighter limits regarding voltage and charge rate related to current temperature from the start may have prevented this early problem with lithium plating, and limited range and charge rate from the beginning.

So if really only a small percentage of all batteries have problems, as most have proposed in this threat, the replacement of the already critical batteries is the right thing. And for all others the tighter limits should be enforced, even there is some loss of range and charge rate.

 

[mjmiron]

The addition of miles has dropped off pre June was at 210 90% now after update 2019.28.1 went to 225 at 90% now today after 2019.28.3.1 back settled at 220. @90%

 

[Todd Burch]

I am now on 3.1 and my 90% charge has not budged at all—still at 215 mi.

 

[dfwatt]

I think the reduction in capacity is affecting everyone.

Nope. Most certainly not affecting everyone as our two cars which spend most of their time in the very hot climate of Florida have had no reduction in range in roughly 10,000 miles each. There is also no discernible charging rate reduction and I was pleasantly surprised to see 60 kilowatts still going into the battery at 80% at my most recent supercharging stop. Admittedly this was a warm battery after a long drive, but I do think that almost all of the discussion on this thread pertains pretty much exclusively to Model S battery packs. The model 3 battery packs do not seem to have the same vulnerability, and my understanding is none of those are Sanyo cells in any case - they are all Panasonic.

 

[Droschke]

On one side all this is part of natural degradation of lithium cells used within manufacturer specification.

If this is really "natural" degradation. The owners' point requesting battery replacement is that if the Tesla BMS could have avoided the damage and for whatever reasons it did not, then it can not be viewed as "natural".

On the other side tighter limits regarding voltage and charge rate related to current temperature from the start may have prevented this early problem with lithium plating, and limited range and charge rate from the beginning.

Correct. Again, what's the purpose of an elaborately advertised BMS if it's not protecting the health of the battery from harm?

So if really only a small percentage of all batteries have problems, as most have proposed in this threat, the replacement of the already critical batteries is the right thing.

Absolutely. The word "small" is highly ambiguous. One can suspect if the "small" is much bigger in size and would incur high cost and, bad publicity (a debatable term but fits in the Tesla's bunker mentality) the replacement is being avoided.

And for all others the tighter limits should be enforced, even there is some loss of range and charge rate.

I would only hope so.

 

[Droschke]

The addition of miles has dropped off pre June was at 210 90% now after update 2019.28.1 went to 225 at 90% now today after 2019.28.3.1 back settled at 220. @90%

It looks like every impacted car gets back about 10 miles (mine did). Merry Christmas.

 

[Chaserr]

If this is really "natural" degradation. The owners' point requesting battery replacement is that if the Tesla BMS could have avoided the damage and for whatever reasons it did not, then it can not be viewed as "natural".

Tesla advertises as much themselves. Creating the World’s Best Service and Warranty Program

Battery Warranty

The battery pack in your car is obviously very important and expensive to replace. In developing the Model S, we took great care to ensure that the battery would protect itself, always retaining a few percent of energy. If something goes wrong, it is therefore our fault, not yours.

Except in the cases of a collision, opening of the battery pack by non-Tesla personnel or intentional abuse (lighting the pack on fire with a blowtorch is not covered!), all damage is covered by warranty, including improper maintenance or unintentionally leaving the pack at a low state of charge for years on end. The battery will be replaced at no cost by a factory reconditioned unit with an energy capacity equal to or better than the original pack before the failure occurred.​

Tesla officially advertised this. They still are advertising this. If this is a BMS failure, they are not fixing it with "an energy capacity equal to or better than the original" - they are doing the opposite in fact by intentionally downgrading the original to less than was sold originally to cover up their own failures. They tell us this is not our fault - it is theirs - and they are stealing from us while going against their own promises making them liars and false advertisers.

Remember when the Model 3 was EPA rated at 335 miles and Tesla asked them to intentionally lower it to 310? And then they slightly increased it to 320 again? That seems eerily similar to what they are doing to us, except they sold us the official EPA number and are trying to impose the limit post-sale.

 

[Ferrycraigs]

IMHO the changes Tesla has made are all connected to the same problem - lithium plating and the consequence - growing of dendrites.

First of all, lithium plating is caused by lithium ions, that cannot intercalate into the crystal lattice of the graphite anode fast enough. Intercalation rate is dependent on temperature. The higher the temperature the more room is for lithium ions.

All owners have noticed that the charging rate at cold temperatures was continuously reduced after the last several years by Tesla. A few years ago it was no problem to get charge rates above 100 kW in winter. But last winter the charge rate dropped very often below 50 kW, if there wasn't a longer high power drive before the stop. For me this is an indication that Tesla has noticed that to high charge rate at to low temperature has negative impact on lifetime. They tried to fix that only for winter time, but noticed that even in summer the charge rate was to high to prevent lithium plating.

So Tesla chose to go all-in and connect current charge rate directly to current battery temperature. In order to reduce the impact, they actively heat the battery on the way to SuCs charging to reduce the impact regarding charge time. But heating takes some time and uses up more energy, that can be recovered only partly because of better charge efficiency of a warm battery.

The strategy regarding temperature and charging seems to be:

Up to a certain SOC (80? %) they try to keep cell temperature in the range between about 40° C (104 F) and 45° C (113 F). This achieves maximum intercalation rate.

They put in a hard stop regarding maximum voltage when detecting a increased dV/dt, which indicates that intercalation rate is slowing down and further lithium plating is risked. To detect this with high accuracy a slow charge rate is better. So they reduced the charge rate above 80 % or above a specific voltage drastically.

The problem with lithium plating is that it is kind of exponential process, because more and more paths to free intercalation volume is clogged by the metallic lithium.

As already mentioned, regarding newer cells of 90+ kWh and M3 batteries, the silicon helps, because with silicon there is no intercalation, but conversion with much higher density. So it is save at this point. But as can be seen with the 90 kWh battery, to much silicon has other negative side-effects, which also limits charging rate.

I have still mixed feelings whether this is covered by the warranty:

On one side all this is part of natural degradation of lithium cells used within manufacturer specification.

On the other side tighter limits regarding voltage and charge rate related to current temperature from the start may have prevented this early problem with lithium plating, and limited range and charge rate from the beginning.

So if really only a small percentage of all batteries have problems, as most have proposed in this threat, the replacement of the already critical batteries is the right thing. And for all others the tighter limits should be enforced, even there is some loss of range and charge rate.

Whilst it is tempting to debate the pros and cons of Dendrites and Li Plating, we don’t know for sure that is even the trigger. The issue, IMO, is for whatever reason, Tesla have artificially capped some batteries in some pre facelift cars. So I am less convinced that discussing degradation helps very much (although I have very much enjoyed the learning process). It’s not a case of sudden degradation, it’s a case of sudden capping. And no-one knows why they have done it (longevity of the battery is the aim, not the cause) and nobody knows why they won’t reverse it.

 

[Muffinman]

Someone at Tesla will eventually leak. Sooner or later.

 

[Chaserr]

Start a GoFundMe / Kickstarter? I'll contribute $1000 to that employee's whistle blower protection fund. We're generally a well-to-do demographic, we can probably cobble together a significant motivation for someone at Tesla to do the right thing.

 

[dfwatt]

Whilst it is tempting to debate the pros and cons of Dendrites and Li Plating, we don’t know for sure that is even the trigger. The issue, IMO, is for whatever reason, Tesla have artificially capped some batteries in some pre facelift cars. So I am less convinced that discussing degradation helps very much (although I have very much enjoyed the learning process). It’s not a case of sudden degradation, it’s a case of sudden capping. And no-one knows why they have done it (longevity of the battery is the aim, not the cause) and nobody knows why they won’t reverse it.

Most of this seems pretty obvious. Tesla has a number of undesirable choices. They can do expensive testing of all the S battery packs to determine which ones have vulnerable cells, and then they would at that point probably have to likely honor a warranty claim for replacement of those cells at huge cost. The second alternative is simply to restrict charging speed and ultimate pack voltage to make sure that all packs that might contain Sanyo cells are not exposed to charging conditions that would elicit this vulnerability. This means a modest loss of range for a lot of people. Tesla decided that this was the better of the two Alternatives. We could argue about whether that's ethical or right, but it's plainly obvious but they would rather have people annoyed with them about loss of capacity and range versus bricked battery packs or battery packs with thermal Runaway.

 

[Droschke]

Whilst it is tempting to debate the pros and cons of Dendrites and Li Plating, we don’t know for sure that is even the trigger. The issue, IMO, is for whatever reason, Tesla have artificially capped some batteries in some pre facelift cars. So I am less convinced that discussing degradation helps very much (although I have very much enjoyed the learning process). It’s not a case of sudden degradation, it’s a case of sudden capping. And no-one knows why they have done it (longevity of the battery is the aim, not the cause) and nobody knows why they won’t reverse it.

Totally agree. As it's been educational as possible and we have learned a lot, we do not know why our battery capacities have been suddenly capped. It's a shame the capper (the party who has done the capping) is still not talking.

 

[Chaserr]

but it's plainly obvious but they would rather have people annoyed with them about loss of capacity and range versus bricked battery packs or battery packs with thermal Runaway.

If it's a safety concern they must inform the proper authorities and issue a recall. This isn't an annoyance it's a criminal matter of theft and you're suggesting it's a larger criminal matter of safety. Recalls can't be avoided by hiding them and this "fix" will miss a lot of cars. How many people will willingly update knowing what we know?

There's a lot of conjecture, but this hypothesis is the least likely reason in my opinion. If a single injury from fire is linked to the owner choosing not to update, it could mean prison for Tesla employees. Updates are voluntary and there is no indication that this downgrading update is any more special or required.

 

[dfwatt]

Tesla advertises as much themselves. Creating the World’s Best Service and Warranty Program

Battery Warranty

The battery pack in your car is obviously very important and expensive to replace. In developing the Model S, we took great care to ensure that the battery would protect itself, always retaining a few percent of energy. If something goes wrong, it is therefore our fault, not yours.

Except in the cases of a collision, opening of the battery pack by non-Tesla personnel or intentional abuse (lighting the pack on fire with a blowtorch is not covered!), all damage is covered by warranty, including improper maintenance or unintentionally leaving the pack at a low state of charge for years on end. The battery will be replaced at no cost by a factory reconditioned unit with an energy capacity equal to or better than the original pack before the failure occurred.​

Tesla officially advertised this. They still are advertising this. If this is a BMS failure, they are not fixing it with "an energy capacity equal to or better than the original" - they are doing the opposite in fact by intentionally downgrading the original to less than was sold originally to cover up their own failures. They tell us this is not our fault - it is theirs - and they are stealing from us while going against their own promises making them liars and false advertisers.

Remember when the Model 3 was EPA rated at 335 miles and Tesla asked them to intentionally lower it to 310? And then they slightly increased it to 320 again? That seems eerily similar to what they are doing to us, except they sold us the official EPA number and are trying to impose the limit post-sale.

Not all Tesla fudging has the same underlying dynamic. The bit of backtracking and doing and undoing around the model 3 range was not related to a potentially fatal flaw in the earlier battery packs in Model S's. I do not believe that anyone has demonstrated that the same vulnerability exists in the Panasonic 2170 cells as exists in the Sanyo 18650s. Also we've got two model 3s and their range and rate of charge has been remarkably stable and of course has gone up under the new supercharging protocols.

 

[Droschke]

Most of this seems pretty obvious. Tesla has a number of undesirable choices. They can do expensive testing of all the S battery packs to determine which ones have vulnerable cells, and then they would at that point probably have to likely honor a warranty claim for replacement of those cells at huge cost. The second alternative is simply to restrict charging speed and ultimate pack voltage to make sure that all packs that might contain Sanyo cells are not exposed to charging conditions that would elicit this vulnerability. This means a modest loss of range for a lot of people. Tesla decided that this was the better of the two Alternatives. We could argue about whether that's ethical or right, but it's plainly obvious but they would rather have people annoyed with them about loss of capacity and range versus bricked battery packs or battery packs with thermal Runaway.

You meant Panasonic, not Sanyo.

Tesla needs to do the right thing. Annoying their most loyal clients is not the right choice, we all should agree.

 

[dfwatt]

You meant Panasonic, not Sanyo.

Tesla needs to do the right thing. Annoying their most loyal clients is not the right choice, we all should agree.

Nope. I actually meant Sanyo. Their 18650 cells appear - overall - more vulnerable than LG's, Panasonic's, or Samsung's. There does appear to be some vulnerability of cells by those other manufacturers, according to the very knowledgeable poster here on this thread, but the predominance of vulnerable cells come from Sanyo by his report. That does not mean that if you have a Panasonic battery pack you're home free on this point. But read his post and you'll see why I said Sanyo.

 

[Droschke]

Nope. I actually meant Sanyo. Their 18650 cells appear - overall - more vulnerable than LG's, Panasonic's, or Samsung's. There does appear to be some vulnerability of cells by those other manufacturers, according to the very knowledgeable poster here on this thread, but the predominance of vulnerable cells come from Sanyo by his report. That does not mean that if you have a Panasonic battery pack you're home free on this point. But read his post and you'll see why I said Sanyo.

The other poster you are referring to, and yes I've read his and all other thousands of posts here, is @Alchemist42 and he did not say our cars have Sanyo 18650 cells. He was talking about Sanyo batteries as an example. Here is his post for you to read again.

 

[scottm]

This is probably my biggest problem with Tesla. They monitor every move you make and can tell you how and what you did in "their" car minute by minute... but you'll never really figure out exactly what they did to the car with updates or why, like even via posting a (real) changelog. I wouldn't be surprised if you go in for abnormal seat wear and the response is "We see that you farted 17 times in your seat in 17,000 miles. We're sorry but that voids your warranty."

Mike

That's why they added Fart mode to the car, to offload your butt.

 

[scottm]

It looks like every impacted car gets back about 10 miles (mine did). Merry Christmas.

I think this is a CYA to say "all customers have regained from what got reduced"