Tesla Motors current and future battery degradation warranty...

[JRP3]

I think low-balling a-la Nissan, and trying to build trust on evaluation of everything else in between is probably the best solution.

The problem I have with low balling is everyone is going to focus on that low number, i.e. "Tesla packs will only have 70% capacity after X years and X miles". Plus such a warranty would not have helped in the case that sparked this discussion.

 

[Kevin Sharpe]

Plus such a warranty would not have helped in the case that sparked this discussion.

Ignore my issues, it's irrelevant here... the fundamental question is what battery degradation warranty should Tesla offer with current and new products?

 

[Chickenlittle]

Please, lets keep Kevin's case out of this thread. There is own thread for that.

Huh. The case is about warrantee and issues it raises. First roadster battery pack is a different issue from model s. The packs are both called battery packs but are different products. Second you could not have warrantee without defining normal activity. How many range charges allowed how far could you take battery down to whatever level. He specifically used cars for long commutes that challenged range. Still doesn't say how many range charges used or whether he relied on the small reserve that is included when you run out (roadster you can recycle key to reach this reserve). I want to emphasize none of this pertains to model s battery. I have charged to 100% in that and run low and used superchargers over 23k miles with 2 mile loss of range. I think it's important to consider battery warrantee issues for different products in different threads

 

[Kevin Sharpe]

I want to emphasize none of this pertains to model s battery.

It has everything to do with Model S and future products. Customers are buying the Model S today with no degradation warranty believing they are covered by a "infinite mile" warranty. This is fine until we get an outlying degradation case. Once that happens who's fault is it? The customers for not reading the small print or Tesla's?

 

[JRP3]

It has everything to do with Model S and future products. Customers are buying the Model S today with no degradation warranty believing they are covered by a "infinite mile" warranty. This is fine until we get an outlying degradation case. Once that happens who's fault is it? The customers for not reading the small print or Tesla's?

How do you know that all customers are unaware of the lack of degradation coverage? No one reads the warranty terms?

Ignore my issues, it's irrelevant here... the fundamental question is what battery degradation warranty should Tesla offer with current and new products?

Good question. I'd like to see your answer.

 

[Kevin Sharpe]

How do you know that all customers are unaware of the lack of degradation coverage? No one reads the warranty terms?

I didn't say all... the point is that some do not.

- - - Updated - - -

Good question. I'd like to see your answer.

I haven't put much thought into this but the Nissan Leaf warranty seems to be well received and might make a good model. Really depends on whether Tesla want to lead or follow.

 

[WarpedOne]

70% is a good model?

Someone is trying to make Tesla shoot into their own foot.

 

[Kevin Sharpe]

70% is a good model?

As I said, that figure has been well received here and would give customers confidence IMO.

 

[yobigd20]

well, I have 56k miles in 18 months on my MS, and I've only seen a 2-3% degredation in max range charge. So I really don't think there's anything to worry about here. The drop in range for me happened within the first 6 months. The last 12 months I've seen 0% degredation. I believe the current MS battery pack and all future tesla battary packs are so advanced and sophisticated and intentionally built with the purpose of minimizing degredation and lasting 20+ years; outside of the roadster's original battery pack this whole discussion on worrying about degredation is pointless and moot. Per the experts these packs were designed to easily last 20 years due to their chemistry and the advanced battery management system and thermal cooling. There is nothing to worry about here. This is not a Nissan Leaf. This is Tesla. And Tesla has already accounted for this in their design such that degredation will be so small by the time there's any significant degredation 20 years later they'll be battery packs out that'll cost like $20 to replace (exaggerated of course, but you get what I mean). Theoretically with these battery packs if your charge cycles are frequent and small these packs could last forever.

 

[Johan]

What if Tesla is as we are speaking gathering real-life data on Model Ss in the wild. The oldest ones and the ones driven most will be the example. Tesla will use data from these cars to define what is normal degradation and will then define abnormal such as for example more than 10% more degradation than the typical case. It would be an equation that may turn out complex and take in to account calendar life, miles driven, range charges, full cycles etc (the vehicle probably stores and remembers these data).

So in effect a customer who claims warranty will be told: we have checked the data from your car and it turns out you have, OR do not have, abnormal degradation as expected from your use of the car. Seems fair to me.

In the end it will be somewhat a subjective call by Tesla. But how is that different from warranty claims with any other part of the car? Brakes? A/C? Suspension? Etc etc.

 

[omarsultan]

In the end it will be somewhat a subjective call by Tesla. But how is that different from warranty claims with any other part of the car? Brakes? A/C? Suspension? Etc etc.

I think the difference is that the other elements are known engineering and the actuaries build reasonably accurate models. The battery pack is still new with not a lot of data--we have what 50K cars, most less than a year old. Its not reasonable to conflate Roadster pack and the Model S pack as the packs are related systems are different beasts.

I think Tesla will eventually do something, because if they have the data to back it up, they can turn low-degradation into a selling point, much as they have done with the drive unit warranty. Until that point, it seems like non-issue. I am at ~35K miles after 14 months, charge to 90% everyday, max charge and Supercharge at least once per twice a week, and last night, my car max charged to 264 miles, so not all that worried.

To be honest, the rest seems to more pot-stirring. Based on the handling of the battery shield and the drive units, if there is an actual trend that needs to be addressed, I expect Tesla will address it in an equitable manner. Kevin's single data point is not a trend.

 

[Chickenlittle]

well, I have 56k miles in 18 months on my MS, and I've only seen a 2-3% degredation in max range charge. So I really don't think there's anything to worry about here. The drop in range for me happened within the first 6 months. The last 12 months I've seen 0% degredation. I believe the current MS battery pack and all future tesla battary packs are so advanced and sophisticated and intentionally built with the purpose of minimizing degredation and lasting 20+ years; outside of the roadster's original battery pack this whole discussion on worrying about degredation is pointless and moot. Per the experts these packs were designed to easily last 20 years due to their chemistry and the advanced battery management system and thermal cooling. There is nothing to worry about here. This is not a Nissan Leaf. This is Tesla. And Tesla has already accounted for this in their design such that degredation will be so small by the time there's any significant degredation 20 years later they'll be battery packs out that'll cost like $20 to replace (exaggerated of course, but you get what I mean). Theoretically with these battery packs if your charge cycles are frequent and small these packs could last forever.

Funny but maybe extremely cheap. Cars taken out of commission all the time by accidents. A totaled car could have a normal battery which could be used for replacement later. Certainly defective batteries a lot fewer than drivers who total cars

 

[scaesare]

Being a Model S owner... I'm certainly interested in the topic as a whole.

Clearly Tesla has a concept of what a "normal" degradation range should be. Therefore there situations that would be classified as "abnormal". Of course this also implies a specific set of conditions, such as number of charge/discharge cycles, temperature, SOC low-watermark, etc...

What would be the implications of Tesla publishing what they uses as their internal benchmark? I'd guess they'd have to do something along the lines of specifying:

- Number of miles and/or "full equivalent" charge cycles
- Logging of min/max temps battery exposed to & duration
- Logging of duration left unplugged
- Low SOC watermark


In thinking about this, existing vehicle manufacturers don't guarantee their (fanciful) mileage estimates over the life of their car either. I know a tank of fuel on my 8-yr old car doesn't go as far now as it did new... of course it's out of warranty now.. .but even within the warranty period, there is no such guarantee I am aware of. Only outright engine failure/malfunction.

Interesting discussion...

 

[omarsultan]

If folks really want to help, fill out the battery survey form: Plug In America

BTW, the prelim results presented at TMC:Connect were very encouraging.

 

[ecarfan]

I am at ~35K miles after 14 months, charge to 90% everyday, max charge and Supercharge at least once per twice a week, and last night, my car max charged to 264 miles, so not all that worried.

That is a very interesting data point. Impressive. Based on my TMC reading over the past year I suspect a lot of the range "loss" some are reporting is because the algorithm cannot accurately calculate range when the car is not regularly charged to over 90%. But many owners worry about how consistently charging the battery to a high level will effect the longevity of the battery. At this point no one knows the answer.

I do think that at some point Tesla will have enough data that they will be able to provide specifics as to how much Model S battery degradation is "normal". But they aren't at that point yet. I doubt they will ever be specific about how much Roadster battery degradation is "normal" because the number of cars produced was very small and the cell type used is no longer in use. The Roadster was a test bed for Tesla technology, it was not a mass production car. I still want one though...

 

[apacheguy]

- Number of miles and/or "full equivalent" charge cycles
- Logging of min/max temps battery exposed to & duration
- Logging of duration left unplugged
- Low SOC watermark

Reasonable except for temperature logging. Tesla markets the Model S as being able to operate in any climate zone of the world. It is the job of the BMS to ensure that undue degradation does not occur.

Aren't we all making this more complicated than it ought to be? Forget the absolute capacity loss. Look at it from a relative point of view. If one sheet in the pack falls far below the others, then Tesla ought to go in and repair the underperforming sheet to restore capacity. That way you don't need to worry about any of the above conditions.

 

[breser]

I feel somewhat responsible for this thread because Kevin asked about the Model S warranty and I responded with the link to the PDF and said that it doesn't.

I think it's pretty clear from the warranty that Tesla is not promising to warranty any battery for range loss. That doesn't mean they can't do so out of goodwill (and from what I've read here it's clear they have done massive amounts of goodwill work in other areas that doesn't qualify under their warranty). So I have to believe in some respects that if there is a vehicle with a failure in the battery that is causing abnormal battery loss that Tesla would warranty it. But as things stands they don't have any obligation to do so.

I do think that many potential buyers will not realize this until they have bought the car. I have a Model S on order. I wanted to read the warranty before I ordered. It was not particularly easy to find the warranty on their website (this was before the warranty was improved for the drive train). I will say that once I'd found it that the location seemed fairly reasonable, but wasn't something that the average buyer was likely to stumble into. On the North America site, the warranty information shows up as links off the specs page for the Model S. The United Kingdom site for instance does not. Once you have a reservation it's fairly easy to (documents section under My Tesla) find but I wonder how many people actually read this at this point.

Currently, on the North American site the main content area is about the "Infinite Mile Warranty" which links you to the blog announcing the increase of the drive train warranty to match the battery. At no point in this blog does it ever actually link to the text of the warranty. Nor does Tesla explain that degradation is not covered. Since this announcement, Tesla has been trumpeting their "Infinite Mile Warranty" on the battery and drive train. Until the drive train articles from Motor Trend and Consumer Reports the biggest fear that every Model S owner had was the battery would lose range or fail. Tesla covers the failure, but does nothing for the range.

Since reading the warranty and realizing this state I have seen multiple times where someone comes along and uses the warranty to say that you're protected from battery degradation with the Model S. I haven't bothered to keep track but this situation from reddit just yesterday comes to mind (and this one is someone that is flagged as a Investor, so I'd think they'd want to know about the warranties the company they are investing in is giving):
stevejust comments on How long will the batteries last?

I'll admit that warranties are usually very hard to find for traditional ICE vehicles on their websites. They also say things like having a bumper to bumper warranty but disclaim warranties on many things. Most of them are considerably less expensive to replace (spark plugs, tires, brakes, etc). However, the consumer public is largely aware of these limitations. Tesla is trying to be a different type of car company. A company that is better than the OEMs in the current marketplace. They can do better on this front.

So what does better mean? Better means telling people clearly what is and isn't covered in an obvious place. More than likely this means that under the Model S popup there should be a warranty page. That doesn't require finding a link on a page that's fully of technical specs and that loads up a PDF, with the warranty shoved all the way at the bottom. Include some explanation of this as part of the ordering process. Yes this might hurt sales initially. But it also means their consumers are fully aware of the risk. Nobody can say "I bought a Tesla and had no idea range degradation wasn't covered." Tesla has actually done a remarkable job of writing the warranty that is easy to read and brief. So they might be able to simply post the warranty and maybe have some bolded bullet points at the top about what is not covered.

Should Tesla cover range degradation? I don't know. I think it might be hard to define what they would cover and not cover due to the variety of ways the battery can be used. Being more up front about the warranty might force them to do something if it hurt sales. But I think in the end the company would be stronger for it. I would no longer have to tell people they should realize that the range is not warrantied.

 

[scaesare]

Reasonable except for temperature logging. Tesla markets the Model S as being able to operate in any climate zone of the world. It is the job of the BMS to ensure that undue degradation does not occur.

Aren't we all making this more complicated than it ought to be? Forget the absolute capacity loss. Look at it from a relative point of view. If one sheet in the pack falls far below the others, then Tesla ought to go in and repair the underperforming sheet to restore capacity. That way you don't need to worry about any of the above conditions.

Agreed, except i was thinking of the the circumstance where a person parks the car in extreme weather for an extended period without plugging in. If, after a while, the car is forced to power down to protect the pack from bricking due to exceeding the low SOC threshold, and then cannot temp-condition itself, it might not "brick", but could have been subjected to temps that compromised it.

 

[bonnie]

I find it hard to believe that people are unaware of EV battery degradation. In the 3+ years of Roadster ownership, I've done countless public events and answered a b'zillion questions. When I first bought the car, I was commonly asked how soon I'd have to replace the battery - and now people register surprise to find that after 30k+ miles, the battery still is in decent shape.

I'm not talking about EV people, but just people off the street. People asking me how I charge the car and does it take a special outlet. And THEY seem to know that batteries degrade.

I've seen some claims by some here on this forum that people are unaware that batteries degrade. While I have no doubt that there are one or two naive people in every crowd, I'm not buying that battery degradation is a hidden fact. The simple fact is that all the EV fud over the last several years has used battery degradation as one of the reasons NOT to buy an electric car. So people always ask about it.

That said, there's nothing wrong with finding the information easily. Just not buying that people don't know.

 

[breser]

I find it hard to believe that people are unaware of EV battery degradation. In the 3+ years of Roadster ownership, I've done countless public events and answered a b'zillion questions. When I first bought the car, I was commonly asked how soon I'd have to replace the battery - and now people register surprise to find that after 30k+ miles, the battery still is in decent shape.

If this is directed at me, I'm not saying that people don't know that batteries degrade. I'm saying that people don't know that the warranty disclaims covering this. I am constantly seeing people say in reaction to discussions about battery degradation "Ohh well the 'Infinite Mile Warranty' means you don't have to worry about that." Which is fundamentally false. Tesla needs to fix that. We need to be clear about this when talking to other people about the risks of buying a Tesla right now.