Life and Death of Li Ion batteries

[anonymous-user]

GT9 said:

https://www.tesla.com/ns_videos/2021-tesla-impact-...

See page 67, I appreciate though that you may be suspicious of Tesla's own data.

Plenty of other nuggets of data in the impact report, what can you find that either concerns you or impresses you?

Article said:

Note: Mileage is only one factor in battery capacity retention; battery age is also a major factor. Retention figures at lower mileages above likely reflect the impact of age while higher mileage values, which come from high-utilization vehicles, likely reflect less influence from battery age. Performance of newer chemistries (not yet shown here) can vary and we plan to expand disclosure once we have sufficient data

I read that, and their idea of Robotaxis (Johnny Cabs?), powered by 1 million mile batteries as aspirational marketing nonsense.


In fact if you read the rest of it, it’s slightly ridiculous. In every comparison or graph “Tesla wins”. Bit like the average EV thread on PH

Edited by anonymous-user on Tuesday 28th February 21:43

[GT9]

wormus said:

I read that, and their idea of Robotaxis (Johnny Cabs?), powered by 1 million mile batteries as aspirational marketing nonsense.

I was referring specifically to the shape of the degradation curve.

There are several documented cases of ultra-high milage taxis, here's one.

https://electrek.co/2020/05/11/tesla-model-x-extre...

No sign of the main battery on the maintenance list???

[GT9]

wormus said:

In fact if you read the rest of it, it’s slightly ridiculous. In every comparison or graph “Tesla wins”. Bit like the average EV thread on PH

If we are doing this whole EV thing anyway, wouldn't it be good if some of the stuff in there had an element of truth to it?

Or are you still in the denial stage of the grief process?

It's a shame anger comes next, I'm starting to warm to you.

[TheDeuce]

CoolHands said:

TheDeuce said:

You're literally making things up as you type. …,myself and everyone else I know typically charges about once a week when the car is down to ~20%,

Amazed you can write that first sentence followed by the second with a straight face. I realise you’re obsessed by ev but that is stretching credulity surely even to yourself

I didn't say I had a straight face - it was still all irritated and eyes rolling from reading the carp you had posted

I stand by what I've said, I'm happy with it. Feel free to go ahead and dredge up some examples of some EV's that have had premature battery issues.. but it won't change the fact that the majority of the very first generation of contemporary EV's have aged perfectly well and remain entirely usable.

There were genuine concerns at the very start, because, as you say, we all 'knew' batteries were crap - they generally are. EV batteries also suffer the same inherent flaws, but in the EV usage scenario, the real life evidence shows that they're actually more than upto the job.

It doesn't matter if you accept the if and whys, all that matters is the final evidence. Just read up and you'll see: https://www.nimblefins.co.uk/study-real-life-tesla...

Here's the key chart:



Surely 230,000 miles is considered pretty respectable and the batteries are still not at 20% degradation loss.

If you look for some really extreme examples you find mega mileage cars which still haven't lost the supposedly important 20%: https://insideevs.com/news/342457/this-tesla-model...

At what point can we just move on and accept that, actually, battery powered cars are up to the job in terms of longevity?

Edited by TheDeuce on Tuesday 28th February 22:00

[CoolHands]

I don’t think mileage has much to do with it, probably why it’s always in these charts. From that study: “ By ten years of age, cars were down to 82.5% of the original capacity”. If that is true and turns out to be fairly accurate, that is pretty bad.

My incredulity at what you wrote was clearly about your claim that most people let their vehicle fall to 20% range before they charge back up, and don’t worry about charging. I simply don’t believe that.

[GT9]

TheDeuce said:

At what point can we just move on and accept that, actually, battery powered cars are up to the job in terms of longevity?

I've just linked to that same car you linked to (I'm guessing its the same one) hitting 400,000 miles!

Conclusive evidence that ALL EVs will make it to 400,000 miles on their first battery. Am I doing this right?

[TheDeuce]

CoolHands said:

I don’t think mileage has much to do with it, probably why it’s always in these charts. From that study: “ By ten years of age, cars were down to 82.5% of the original capacity”. If that is true and turns out to be fairly accurate, that is pretty bad.

My incredulity at what you wrote was clearly about your claim that most people let their vehicle fall to 20% range before they charge back up, and don’t worry about charging. I simply don’t believe that.

If you don't think that the number of charge cycles has a big impact on battery degradation then... I can't help you with that. The evidence that it does and explanation for why and how it does is not hard to find.

I said most people I know run down to ~20% charge, or whatever works for them - which is true. We all charge approx once a week. I don't know why that is so hard for you to accept? Of course you charge overnight if you're expecting to do a long journey the following day, but if on day 6 of the week you have 32% charge remaining, why would you worry about it if all you have to do the following day is typical short journeys around the area you live? Most people don't do long journeys all that often so there is no worry. The average UK motorist does less 8k miles a year these days, 20 odd miles a day. If my EV is at 32%, that's 64 miles of real world range, that's enough for me not to bother plugging it in until the following day.

Serious question.. Do you really have any basis to your assumption that EV owners try and keep their car well charged up whenever possible? Or is it your own doubts about what it would be like to live with an EV that has led to that assumption?

[TheDeuce]

GT9 said:

TheDeuce said:

At what point can we just move on and accept that, actually, battery powered cars are up to the job in terms of longevity?

I've just linked to that same car you linked to (I'm guessing its the same one) hitting 400,000 miles!

Conclusive evidence that ALL EVs will make it to 400,000 miles on their first battery. Am I doing this right?

Well it's tricky. I also found an example of a Tesla that had a failed battery just 8000 miles in so that is conclusive evidence that all EV's can never last as long as an ICE and are a terrible solution!

It's difficult this stuff isn't it

My personal view is that there are always extremes, and that generally articles are only written about extremes.. But everyone I know who has an EV hasn't suffered any real problems or noticed a worrying amount of battery degradation. Virtually everyone on these forums that has one tends to say they would have another, and if some examples can do a documented 400k miles + on the original battery, then we know for damn sure the majority will happily do over 200k miles at which point the question is answered - no, EV's do not have an inherent problem matching the lifespan of an ICE car.

People can argue about the details all they want, and they can post articles all they want. But it won't change the fact that the people in California who snapped up the first Tesla's are still driving around ten years later perfectly happily in cars with minimal degradation. Certainly less degradation than was warrantied against when they chose to buy the car in the first place..

[NMNeil]

SWoll said:

Why do you consider 80% a watershed?

A current Model 3 LR at 80% battery life would still be capable of 250 miles between charges. Hardly at the end of its useful life and still considerably more than many other EV's when new?

Tesla warranties it's batteries to maintain 70% of capacity after 100,000 miles or 8 years, whichever comes first. Tesla's sold in California have the warranty extended to 150,000 miles or 10 years.
But Tesla batteries don't seem to degrade much anyway.

https://evannex.com/blogs/news/understanding-tesla...

[TheDeuce]

NMNeil said:

SWoll said:

Why do you consider 80% a watershed?

A current Model 3 LR at 80% battery life would still be capable of 250 miles between charges. Hardly at the end of its useful life and still considerably more than many other EV's when new?

Tesla warranties it's batteries to maintain 70% of capacity after 100,000 miles or 8 years, whichever comes first. Tesla's sold in California have the warranty extended to 150,000 miles or 10 years.
But Tesla batteries don't seem to degrade much anyway.

https://evannex.com/blogs/news/understanding-tesla...

I'm sure part of the concern people have is that the manufacturer warranties suggest the batteries won't last as long as they need to in order to make sense of buying an EV. But what else can the manufacturers do? EV's are new, they can't launch with 160k/12 year warranties as they only had theoretical data to suggest that would be realistic, so they had to play it safe. They're learning the real world results at the same time we are, by waiting and seeing.

Tesla were the first to market so we have their results now, we're seeing thousands of cars reach the ten year mark with very respectable mileage and they're generally absolutely fine. That will likely give the confidence to Tesla and other to start increasing their battery warranties, and they will all want to offer the greatest warranty they safely can because, of course, buyers will find comfort in a more substantial warranty offering.

This is all new, it's going to take time for everyone involved, especially the buyers, to find an appropriate level of confidence. But early results are more than good enough for the average motorist.

[GT9]

NMNeil said:

Tesla warranties it's batteries to maintain 70% of capacity after 100,000 miles or 8 years, whichever comes first. Tesla's sold in California have the warranty extended to 150,000 miles or 10 years.
But Tesla batteries don't seem to degrade much anyway.

https://evannex.com/blogs/news/understanding-tesla...

Wrong thread.
You can't just post up data showing the degradation tailing off like that, this thread is only for data that shows the opposite.
Start your own thread.

[Nomme de Plum]

CoolHands said:

I don’t think mileage has much to do with it, probably why it’s always in these charts. From that study: “ By ten years of age, cars were down to 82.5% of the original capacity”. If that is true and turns out to be fairly accurate, that is pretty bad.

My incredulity at what you wrote was clearly about your claim that most people let their vehicle fall to 20% range before they charge back up, and don’t worry about charging. I simply don’t believe that.

Why not? Is your belief just an act of faith or do you have some evidence?

I didn't fill my ICE until the old reserve thingy came on so why would I with an EV. Longer runs slightly different but your assertion has no logic.

I've always done the same with iPhone, iPad and watch.

[NMNeil]

GT9 said:

NMNeil said:

Tesla warranties it's batteries to maintain 70% of capacity after 100,000 miles or 8 years, whichever comes first. Tesla's sold in California have the warranty extended to 150,000 miles or 10 years.
But Tesla batteries don't seem to degrade much anyway.

https://evannex.com/blogs/news/understanding-tesla...

Wrong thread.
You can't just post up data showing the degradation tailing off like that, this thread is only for data that shows the opposite.
Start your own thread.

Sorry. Are these acceptable?
https://www.autoevolution.com/news/this-2018-tesla...
https://insideevs.com/news/342457/this-tesla-model...

[CoolHands]

Most (evidence - 50 years on this planet with all sorts of drivers) people don’t let their cars fall to less than a quarter of a tank regularly, and we know (us non believers) that range anxiety is heightened with ev not lessened so it doesn’t make sense that that is how people behave.

We also know that most / many people leave phones on charge overnight hence why manufacturers have got software to manage it now. So just because you don’t doesn’t make you typical.

[TheDeuce]

Nomme de Plum said:

CoolHands said:

I don’t think mileage has much to do with it, probably why it’s always in these charts. From that study: “ By ten years of age, cars were down to 82.5% of the original capacity”. If that is true and turns out to be fairly accurate, that is pretty bad.

My incredulity at what you wrote was clearly about your claim that most people let their vehicle fall to 20% range before they charge back up, and don’t worry about charging. I simply don’t believe that.

Why not? Is your belief just an act of faith or do you have some evidence?

I didn't fill my ICE until the old reserve thingy came on so why would I with an EV. Longer runs slightly different but your assertion has no logic.

I've always done the same with iPhone, iPad and watch.

I hadn't even given the 20% as what 'most' people run down to, I just know it's typically my trigger to charge, and I charge roughly once a week. My EV driving friends in town also charge about once a week so I'd guess about the same for them.

The funny thing is, my fairly casual comments about the routines of my friends and myself has received criticism for not being realistic from someone who actually claimed that 'every' EV driver keeps their car fully charged all the time!! I clearly know that can't be true because I am an EV driver and don't do that!

I can sort of understand his assumption though. When I ordered my first EV I did spend a lot of time wondering if I'd done the wrong thing, I had to keep reminding myself that logically, the lower range than previous ICE cars wouldn't affect me, because I so rarely exceed it. I had to keep reminding myself that it doesn't matter that it takes 12 hours to 'fill up' at home, because I would be asleep. After so many years of running ICE cars, logic wasn't enough to fully calm me, there was a part of me that still innately doubted my choice. Now I'm 3 years in, guess what? Logic was correct - of course. It's great and I won't go back to ICE for a daily, the EV is far more convenient. But I did have that moment and whenever I'm 'debating' on these forums with someone who can't seem to apply logic, I do remind myself that at one point in time, I too suffered a rare yet powerful mental block about the same sort of stuff, even though it should all be pretty clear to understand.

This I suspect is the root cause of so many extended debates on these forums. A lot of the time those that live with EV's are debating with people that have not and their natural stance against changing away from what has felt normal and worked fine for their entire time as a driver is more powerful than logical evidence to the contrary. They can only see the differences in ICE vs EV in terms of what is worse/less, they can't see beyond those things to consider the benefits of a new type of powertrain. Which is quite annoying, but I do understand it - to a point.

Although anyone that claims all EV drivers maintain a full charge at all times is pushing the limits a little

[TheDeuce]

CoolHands said:

Most (evidence - 50 years on this planet with all sorts of drivers) people don’t let their cars fall to less than a quarter of a tank regularly, and we know (us non believers) that range anxiety is heightened with ev not lessened so it doesn’t make sense that that is how people behave.

But you can with an EV so long as you don't have a lengthy journey planned the following day, why would you care? You set your own 'comfort level' for min charge on any given day and when you approach that point you plug in, safe in the knowledge when you wake up it'll be brim full again.

As for range anxiety, see my post above. It was massive for me, illogically, until I took the jump. Then I quickly proved to myself how utterly irrelevant it is because my car can be charged overnight to easily achieve whatever typical range I might need the following day. If it's a longer journey, it's actually just fine, I'm happy to stop to charge for lunch or somewhere interesting and I'll admit it would be amazing if I had the option to refill in 2 minutes, not an hour... but the cost savings and time savings the rest of the year more than make up for it. I only charge en-route maybe 4-5 times a year, I'd rather that than a weekly petrol station visit and £2000 in fuel vs £300 in volts. I'm happy to wait to charge 4-5 hours a year for a £1700 saving, that's a decent hourly wage

Admit that there is a side to this debate you hadn't fully considered..?

[off_again]

Oh great, another "EV's are terrible" article. I am the first to jump in on Tesla when they screw up, but on this one I will defend them.

Yes, there is a degradation factor to consider with an EV, but they will drop capacity with the first few years and then level out the degradation from there. There will be degradation, but it will lessen. The article does highlight that their data might not be perfect, but they arent taking into account the change in battery packs over the years. More modern Tesla's use improved battery packs and they have changed quite a lot. Constant revisions to the battery pack management have also meant that things are slowly but steadily improving.

But there are other factors here. Others have mentioned about the warranties available from Tesla and of course you can get extended warranties too. Tesla has made some pretty outrageous claims in the past, but there are proven to be reliable around their battery packs and motors (well from the last few years of course). And yes, when the pack does degrade, it will need replacement - but of course as the demand increases, so will the aftermarket services. There are a bunch of companies already here that offer battery pack renewal services and they are at a fraction of the cost of a new one. When your trusty 10 year old ICE car has lost some ponies, do you just throw the engine away and buy a new one from the manufacturer? Or do you take it to a specialist and have it resolved?

I think its foolish for people to think that EV's are almost free from servicing. You must maintain them and given that they have a few components that are VERY expensive, it makes sense to keep a rainy-day fund for that, if you cant get a warranty policy. Just like running a 10 year old expensive car comes with risks, so does running a 10 year old EV. Keep on top of the servicing, get a warranty and make sure you have a mechanism to fix it should it go wrong and you should be good to go. But there is a cost there somewhere, just be aware where it is.

[anonymous-user]

GT9 said:

I was referring specifically to the shape of the degradation curve.

Sorry, it’s a Tesla sales brochure and it’s absurd to suggest it’s still got over 90% capacity after 100k miles. 80% might be realistic I’d guess but then these batteries are considered “dead” by 70% so the question is, if you buy a 100k, 10 year old Tesla, with unknown charging/usage history, how much life does it still have? These are the useful answers for skeptics like me to ever consider buying one, not the naive “EVs are amazing!!!!!” bilge which seems to permeate these threads.

[GT9]

wormus said:

Sorry, it’s a Tesla sales brochure and it’s absurd to suggest it’s still got over 90% capacity after 100k miles. 80% might be realistic I’d guess but then these batteries are considered “dead” by 70% so the question is, if you buy a 100k, 10 year old Tesla, with unknown charging/usage history, how much life does it still have? These are the useful answers for skeptics like me to ever consider buying one, not the naive “EVs are amazing!!!!!” bilge which seems to permeate these threads.

Sales brochure, ok.

Ignore the absolute values then, what about the shape?

Have you looked at any of the other data presented in this thread and what SHAPE the degradation curves are following?

[anonymous-user]

GT9 said:

wormus said:

Sorry, it’s a Tesla sales brochure and it’s absurd to suggest it’s still got over 90% capacity after 100k miles. 80% might be realistic I’d guess but then these batteries are considered “dead” by 70% so the question is, if you buy a 100k, 10 year old Tesla, with unknown charging/usage history, how much life does it still have? These are the useful answers for skeptics like me to ever consider buying one, not the naive “EVs are amazing!!!!!” bilge which seems to permeate these threads.

Sales brochure, ok.

Ignore the absolute values then, what about the shape?

Have you looked at any of the other data presented in this thread and what SHAPE the degradation curves are following?

Yes, it’s an ‘S’, I get it. The point being battery performance drops significantly in the first 20k miles, stabilises (notwithstanding chemical and age degradation of say 2-3% each year), then it drops significantly between 80% capacity - 70%, by which time it needs replacing.


What’s not clear is at what point that final drop in performance happens. The fact most manufacturers provide a warranty until 100k suggests it’s not too long after that.

Edited by anonymous-user on Wednesday 1st March 08:41