Wiki Sudden Loss Of Range With 2019.16.x Software

[mjmiron]

I haven't been on the forums in a while but I'm effected by this as well. My S85 was delivered 3/2014 and the 90% suddenly dropped from 230-235 to 210-215 in the last two months. I figured it was just battery aging but it was pretty sudden and surprising after 85,000 miles in the car.

This doesn't effect me daily but it does when I drive from College Station to downtown Houston and back. This used to end with a good 10-15% left at the end of the trip but now it is shaving it REALLY close so much so that I now tend to stop on Hwy 290 and supercharge for 10 minutes to make sure I have enough juice.

Sounds like you were affected your about the 3rd person after the news to post thank you. We are all hopeful for a fix.

 

[MP3Mike]

The issue is not that the battery lost range over time due to normal degradation, instead the issue is that these batteries have some form of internal fault that increases the likelihood of self combustion

You are assuming facts that are not in evidence.

 

[DaveBC]

• If not - if you were being responsible and charging only to 80-90% daily - then just change your daily charge to 95-100% and you've got your daily range back, and your level of stressing your batteries is exactly the same as it was before the update, because you're charging to the exact same voltage. Only long trips are affected.

Am I missing something? Is this just about trips?

Your solution requires owners to know that 100% is only 4.07v and now totally safe to set their daily charge at. An owner shouldn't be required to know this or do this. If for a moment we imagine everyone is ok that packs had to be limited like this the slider should stop at 89% or the vehicle should stop charging and report 89%. Not show 90% when they are at 80%.

Imagine if your solution were absorbed into the Tesla owners conventional wisdom? "Oh Bill, your rated range dropped 10% overnight? Don't worry you've got Zpack. Slide that limit to 100 and carry on!"

 

[Zodiacchris]

Hi Karen,
How does the limitation affect me? Well, here in Australia superchargers are pretty far apart, even on the main routes. I fly paragliders and the inland flying site I normally travel to on the weekend has a gap of 290km between superchargers from Port Macquarie to Tamworth, hilly terrain and there are no other charging options on the way. I managed with the old range, but not with my current restricted range. If I go other places I now have to stop at every supercharger on the way and can’t go around inconvenient ones (bloody inconvenient to go into the Sydney CBD on a Friday afternoon with traffic a nightmare). Combined with having to wait an extra 40 minutes at each stop because the charge rate is low, it’s just super inconvenient.
But what really annoys me even more is that I have started to avoid talking to people about my Tesla and praising EVs, because there is this massive BUT now. I love my MS, it drives super smooth and powerful, but it seems like my battery is degraded after only 3 1/2 years and 55 thousand miles, and I have lost 53 miles from new. The standard question, how long does it take to charge? Well, in May it was 45minutes, at the moment its 90 minutes to the next supercharger, and God knows how long it will be next week. I just don’t feel I can recommend it to my friends any more.

So yeah, it is not life changing (and I still really love my S), but it sucks...

 

[KarenRei]

The issue is not that the battery lost range over time due to normal degradation, instead the issue is that these batteries have some form of internal fault that increases the likelihood of self combustion and the response has been to intentionally and suddenly reduce the maximum charge to minimize the risk.

The key point is that all li-ion batteries, even when brand new, are:

• At risk of self-combustion if charged beyond certain voltage / current limits (which vary greatly based on conditions and the how the various aging processes have affected the cells)
• At risk of unacceptable levels of degradation if charged beyond certain voltage / current limits (same as above)

Which is why you always have limits coded into the BMS. Again, that's the BMS's job.

A key limiting factor in charging is anode intercalation rates. Intercalation of lithium ions into the anode is energetically preferable to plating lithium; they "want" to intercalate rather than plate out. But the rate at which intercalation can proceed varies depending on the conditions - and each of these can be seen in how the BMS manages charging.

• Ion mobility, and thus intercalation rates, are strongly dependent on temperature. In practice, you see this as very slow charging until the battery warms up.
• Intercalation slows down the more lithium there is already intercalated in the anode. The BMS responds with what you see as taper.
• Above a certain point, intercalation has slowed to such an extent that you can A) no longer reliably ensure no lithium plating, and or B) the high reactivity of the anode makes for an unacceptable level of reaction with the electrolyte, and thus degradation. You see this as the cutoff.

It's long been clear that the packs in question were not living up to the desired longevity standards.

• First off, we got the nerfed Supercharging after a fixed number of sessions in 2017. This clearly spells out Tesla's concern: after a given number of sessions, they can no longer trust that intercalation is proceeding fast enough for the full ~120kW charging. Ion mobility is suffering as the packs age and in particular as they are supercharged - hence the limits which quite clearly spell out the problem.
• Now we get this - a voltage limit, and possibly a further charging limit. A voltage limit at the upper end would more commonly be interpreted as protecting the battery from excessive anode-electrolyte reactions - and that might well be. But combined with the charge rate (and thus intercalation) limits, it looks more like they cannot trust the reliability of intercalation at the upper end of the packs. The problem could also be both.

Why didn't Tesla's accelerated aging tests detect this problem? It's hard to say; accelerated aging is a very difficult thing to do reliably (it's even possible that there were QC issues on the anode powder that were out of Tesla's control). I'd love to know what went wrong, but I doubt we ever will. But acceptable intercalation rates have clearly fallen far faster than Tesla expected them to vs. how these packs were testing when new. As they age, the anodes just aren't soaking up the lithium like they're supposed to - at least not reliably.

Can you force them to charge faster? Of course you can. Just like you can try to force new cells with new chemistries to charge much faster and to maximum theoretical voltages than they already do. But it's the BMS's job to stop you from doing what's possible, and instead limit you to what's reasonable. Sure, it "works" - but you're taking away 9s in that reliability game. Whether the issue is safety or longevity, it's the BMS's job to stop you from hurting yourself. The more a manufacturer learns, the more they change the BMS's algorithm. If the news you learn is good, charge rates, tapers, max voltages etc improve. If the news is bad.... well, this happens. And it sucks for those affected.

But this is the BMS's job. And it is absolutely right to update the BMS based on the information that you collect over time as to how packs with that chemistry are aging - for good or for bad.

To sum up:

• Packs are always limited. From the very day you pick up the car. That's the BMS's job.
• The limits in the BMS should be updated based on the latest information - good or bad.
• The ability of lithium to be reliably intercalated into the anodes clearly has degraded faster than the company anticipated - hence the chain of downgrades over time.
• Nothing in the warranty guarantees a minimum range
• People absolutely have a right to be upset about how much the range is dropping
• Tesla should try to do something for them, without setting a trend of "non-warranty-covered fixes will occur at Tesla's cost any time people are disappointed with something". What would be appropriate is reasonably up for debate.
  • Rolling back the changes and pretending that anode degradation isn't happening, however, is not a reasonable choice.
• Tesla failing to communicate when there's bad news they have to deal with is understandable (who wants to broadcast negative PR when you can just handle the issue silently?), but incredibly frustrating for affected individuals.

That's just my two krónur.

 

[sdoorex]

You are assuming facts that are not in evidence.

I am extrapolating it from two things. First, Tesla's official response to Electrek about the lawsuit regarding the loss as a result of an update to improve battery longevity:

Delivering the best possible customer experience with the highest regard for safety has always been our priority, and we do not disregard either of these things as this complaint suggests. A very small percentage of owners of older Model S and Model X vehicles may have noticed a small reduction in range when charging to a maximum state of charge following a software update designed to improve battery longevity. As previously noted, we have been working to mitigate the impact on range for these owners and have been rolling out over-the-air updates to address this issue since last week.

Second, the update in question occurred shortly after and in response to the fires in Hong Kong and Shanghai and here's Tesla's official statement regarding said update:

As we continue our investigation of the root cause... we are revising charge and thermal management settings on Model S and Model X vehicles via an over-the-air software update that will begin rolling out today, to help further protect the battery and improve battery longevity.

Please correct my interpretation if you think it is wrong however most of us are speculating either way in the thread and the only way to get the truth will be through the discovery phase of a lawsuit however this seems like the most plausible explanation.

 

[DJRas]

As a side note - and this is more out of curiosity - how is this actually affecting people's daily lives? I'm seeing range drops reported like 10-15% (for example, David Ramussen: 247->217mi). Were you guys actually charging to 100% daily before the drop?

• If so, then your batteries should be degraded even if there were nothing wrong with the pack, and it'd be your own fault. Everyone knows (or at least should know) that you're not supposed to charge to 100% daily unless you have absolutely no other choice (wherein even "slow" degradation will eventually ruin things for you).
• If not - if you were being responsible and charging only to 80-90% daily - then just change your daily charge to 95-100% and you've got your daily range back, and your level of stressing your batteries is exactly the same as it was before the update, because you're charging to the exact same voltage. Only long trips are affected.

Am I missing something? Is this just about trips?

I have a 250+ mile round trip commute.
I was supercharging to 90% (from 20-40% start SOC) and could get from a convenient supercharger to work and back home to charge again to 90%.
Since the update I cannot even get the old 90% range at 100%.
So, I now MUST supercharge twice per day to make my commute.
I now pull into the supercharger with 15% or less (20 - 30 miles) with 50 required to reach home.
Plus, since supercharging has been slowed (especially beyond 90%) I am spending at least an extra hour per day to my commute.
I TRIED to get to 100% last night from 15% and at 2:30 charging stopped at 98%.

Other trips I have been able to make round trip from home to Los Angeles doctor now MUST include a stop at a supercharger.
I only charged beyond 95% 8 times in the year prior to May 13, 2019.

 

[TJtv]

Ironically you'd be more likely to have your car covered under warranty if you decline the updates and that causes your car to catch on fire. Surely they can't claim that a car that spontaneously combusts is not covered under warranty, can they? But once you update and your battery is artificially capped, they don't consider that a warrantable item.

 

[KarenRei]

I guess I'll also add that the fact that intercalation rates are limited is also a concern for an outright pack failure. When a cell first starts being charged, you build up a SEI (Solid-Electrolyte Interface), which in many ways is a good thing, as it helps prevent further anode-electrolyte reactions. But as it (and further slowly-accumulating byproducts) builds up, it starts clogging up the pore space in the electrode (particularly a problem on the anode end). This can lead to degradation curves where it starts out quickly, then degradation plateaus.... then suddenly drops off when the pore space to deeper in the anodes has been completely closed off, and so you're only intercalating into the outermost layers.

Even if your "remaining charge graphs" were an accurate measure of battery health (the short of it: they're not, they're just what the BMS happened to think the health was based on what it thought it knew at the time), they can be deceiving, because plateaus can abruptly end.

 

[sdoorex]

It's long been clear that the packs in question were not living up to the desired longevity standards.

I agree, which is why I am calling the batteries defective.

Rolling back the changes and pretending that anode degradation isn't happening, however, is not a reasonable choice.

I agree, which is why I have not suggested removing the software limitation on the affected batteries.

 

[DJRas]

The key point is that all li-ion batteries, even when brand new, are:

• At risk of self-combustion if charged beyond certain voltage / current limits (which vary greatly based on conditions and the how the various aging processes have affected the cells)
• At risk of unacceptable levels of degradation if charged beyond certain voltage / current limits (same as above)

Which is why you always have limits coded into the BMS. Again, that's the BMS's job.

A key limiting factor in charging is anode intercalation rates. Intercalation of lithium ions into the anode is energetically preferable to plating lithium; they "want" to intercalate rather than plate out. But the rate at which intercalation can proceed varies depending on the conditions - and each of these can be seen in how the BMS manages charging.

• Ion mobility, and thus intercalation rates, are strongly dependent on temperature. In practice, you see this as very slow charging until the battery warms up.
• Intercalation slows down the more lithium there is already intercalated in the anode. The BMS responds with what you see as taper.
• Above a certain point, intercalation has slowed to such an extent that you can A) no longer reliably ensure no lithium plating, and or B) the high reactivity of the anode makes for an unacceptable level of reaction with the electrolyte, and thus degradation. You see this as the cutoff.

It's long been clear that the packs in question were not living up to the desired longevity standards.

• First off, we got the nerfed Supercharging after a fixed number of sessions in 2017. This clearly spells out Tesla's concern: after a given number of sessions, they can no longer trust that intercalation is proceeding fast enough for the full ~120kW charging. Ion mobility is suffering as the packs age and in particular as they are supercharged - hence the limits which quite clearly spell out the problem.
• Now we get this - a voltage limit, and possibly a further charging limit. A voltage limit at the upper end would more commonly be interpreted as protecting the battery from excessive anode-electrolyte reactions - and that might well be. But combined with the charge rate (and thus intercalation) limits, it looks more like they cannot trust the reliability of intercalation at the upper end of the packs. The problem could also be both.

Why didn't Tesla's accelerated aging tests detect this problem? It's hard to say; accelerated aging is a very difficult thing to do reliably (it's even possible that there were QC issues on the anode powder that were out of Tesla's control). I'd love to know what went wrong, but I doubt we ever will. But acceptable intercalation rates have clearly fallen far faster than Tesla expected them to vs. how these packs were testing when new. As they age, the anodes just aren't soaking up the lithium like they're supposed to - at least not reliably.

Can you force them to charge faster? Of course you can. Just like you can try to force new cells with new chemistries to charge much faster and to maximum theoretical voltages than they already do. But it's the BMS's job to stop you from doing what's possible, and instead limit you to what's reasonable. Sure, it "works" - but you're taking away 9s in that reliability game. Whether the issue is safety or longevity, it's the BMS's job to stop you from hurting yourself. The more a manufacturer learns, the more they change the BMS's algorithm. If the news you learn is good, charge rates, tapers, max voltages etc improve. If the news is bad.... well, this happens. And it sucks for those affected.

But this is the BMS's job. And it is absolutely right to update the BMS based on the information that you collect over time as to how packs with that chemistry are aging - for good or for bad.

To sum up:

• Packs are always limited. From the very day you pick up the car. That's the BMS's job.
• The limits in the BMS should be updated based on the latest information - good or bad.
• The ability of lithium to be reliably intercalated into the anodes clearly has degraded faster than the company anticipated - hence the chain of downgrades over time.
• Nothing in the warranty guarantees a minimum range
• People absolutely have a right to be upset about how much the range is dropping
• Tesla should try to do something for them, without setting a trend of "non-warranty-covered fixes will occur at Tesla's cost any time people are disappointed with something". What would be appropriate is reasonably up for debate.
  • Rolling back the changes and pretending that anode degradation isn't happening, however, is not a reasonable choice.
• Tesla failing to communicate when there's bad news they have to deal with is understandable (who wants to broadcast negative PR when you can just handle the issue silently?), but incredibly frustrating for affected individuals.

That's just my two krónur.

You seem to be completely misstating the facts.
Yes, the BMS limits charging to the battery. Specifically it reduces charging current as the pack nears max voltage.
The Max voltage is ALWAYS 4.2 volts in every Tesla battery pack ever produced (except for the software limited pack they sold for convenience sake - 75 kWh packs in 60 cars).
As the batteries degrade the max voltage does not change. I have verified this with badly degraded 60s that now only have 45kWh available.
Yes, nothing the the warranty expressly states minimum range. Tesla Service people told be that their standard is 10% beyond fleet-wide average for a given battery module type for Model S and X.
This range loss is absolutely NOT normal degradation. It is limiting the max charge voltage (for completely unknown reasons outside of Tesla). This is borne out by the fact Tesla now states that the range loss will be reversed by the software released over the last week. Therefore, this is NOT normal degradation, It is NOT to protect the batteries from fires.
It was a bug in the software release that has now taken 12 weeks to get something that Tesla has only told the press when questioned but has not shared with any of us affected owners directly.

 

[Droschke]

There is always a spread between the behaviour of the different batteries (and some of it depends on environmental factors and charging history).

No manufacturer will guarantee that everyone gets above average batteries (they do sell outside of the Lake Wobegon area).

"Defective" is "outside of the normal range", but customers cannot at will define what range they would like to see means a battery is seen as "defective".

For model 3 owners, Tesla has been more careful to define what is definitely abnormal, and the bar is awfully low: 70% at the end of the warranty period, which is 8 years or 192000km, whichever comes first. They might treat customers skating close to that limit as "abnormal" once they gathered fleet data that allows them to more accurately see what is normal (and replace batteries when a user is seen as being in the 5% of unluckiest users), but they haven't put that stick in the ground.

Also, charging limits imposed when someone is worried about a hitherto unforeseen condtion are usually precautionary. Just hypotethically, suppose they see a rise in the risk of fire for some batteries, which could have lethal effects, I would rather want them use an abundance of caution in setting limits until they gathered more data, and only then attempt to restore more range to more customers. If someone dies, then that's not something you can fix by installing some new firmware.

A nice but very long answer to a question which was not asked, although it might just work in Lake Wobegon

This what you posted about unsafe batteries:

... certain batteries have become unsafe to charge to the same voltage as new ones (or older ones that have not degraded in the same way) ...

I asked you then, and I am asking you again, if the batteries are assumed to be unsafe, can it be that the same unsafe batteries are also considered defective?

A yes or no would suffice.

 

[MP3Mike]

This is borne out by the fact Tesla now states that the range loss will be reversed by the software released over the last week.

They didn't say that...

 

[Droschke]

Would you rather the BMS not do its job?

I fixed it per below:

Is it possible the BMS has not been and is still not doing its job?

If it hasn't, then there is a good possibility that the packs have been damaged as the result. If is still not, then it's FUBAR.

 

[CuriousG]

I know of 40 on this thread. Another 20 in Europe.
What do you think the odds are that everyone affected is on this forum? There are some 200,000 model S 70s, 75s. 85s and 90s. There are not 200,000 menbers here.
However, Tesla has the means to know EXACTLY how many and which exact cars ARE affected.

When this initially happened to me and I visited a service center, since I could not get a hold of anyone that could answer my question, I plugged in at the Supercharger there to walk to service. On the way, I decided to ask another person charging if they noticed their range had dropped dramatically. I explained the situation and he didn't pay attention. That was the first and only time I asked. But I'd venture to guess most people don't pay much attention so the number of people that are affected is skewed.

 

[KarenRei]

I asked you then, and I am asking you again, if the batteries are assumed to be unsafe, can it be that the same unsafe batteries are also considered defective?

Even new batteries of the newest chemstries are unsafe if you're too aggressive with your BMS settings.

Is it possible the BMS has not been and is still not doing its job?

It's possible that any BMS in any EV isn't doing its job.

 

[CuriousG]

They told him that new releases will fix this range issue. That sure seems like Tesla still believes the batteries are fine. It was a bug. Not Lithium dendrites or lithium plating.

If this were true, this thread could have been quashed weeks ago. But instead Tesla kept telling lies which resulted in your lawsuit.

 

[Droschke]

This post needs to be revisited in light of the recent activities in this thread. Notice this reminder:

Get ready for the same crowd to come out of the woodwork for YOU all too.

 

[Ferrycraigs]

Even new batteries of the newest chemstries are unsafe if you're too aggressive with your BMS settings.

It's possible that any BMS in any EV isn't doing its job.

But is anyone suggesting the BMS settings are too aggressive in Teslas? I thought 4.2V was pretty much an industry standard specification. Presumably the BMS settings start off exactly the same for the entire fleet. For 99% (assumption) of Teslas, the BMS seems to be working just fine. The bit I struggle with is Tesla decided to change Vmax in only 1% of the fleet. Why would they do that? It’s hard to avoid the conclusion that they did so because something was wrong with those batteries, or they had conditions that might lead to something going wrong, conditions that were not apparent in the 99% of batteries that haven’t been affected by the Vmax capping. And I thought BMS’s job was to avoid any such conditions. So I am open to suggestions as to why these 1% of batteries needed special attention unlike all the rest. It seems charging patterns, such as high SoC % or high incidences of Supercharging is not the trigger as there are many examples of owners that have not treated their battery in that fashion (I am one) yet still have had their battery capped. So whilst I absolutely do not disagree with your statements as generic facts, they seem less plausible to those affected by the capping. I think it would be difficult to argue against the 1% having had some defect, or were more prone to a defect, or conditions leading to a defect. Given the numbers in the fleet is it is not reasonable to assume 1% of batteries are of a poorer quality to start with, of a quality that might lead to a defect?

It is of course possible that any BMS isn’t doing it’s job. But we are primarily interested in the BMS of the 1% of batteries that Tesla thought needed some help. And what the reasons could be for the BMS apparently being less effective with the 1% when it seems to have done its job just fine with the 99%. (The opinions and questions of a non expert - me)

 

[MP3Mike]

Interestingly, Tesla replied to Fred from Electrek.

They told him that new releases will fix this range issue. That sure seems like Tesla still believes the batteries are fine. It was a bug. Not Lithium dendrites or lithium plating.

So if it turns out that Tesla is actually pushing a new firmware version that fixes the range issue, how quickly will you be dropping your class action lawsuit?