I think batteries aging as much as they do is a thing we will be able to solve. Dr. Jeff Dahn's talks on YouTube were really striking in how much a bit of chemistry and charging management gets you.
Having studied battery lifetimes in an engineering context for a significant amount of time I've regularly wondered how much of the slow battery degradation in these car battery packs is "cheating".
That is how much of the battery capacity is hidden by the battery management system when the car is new and then slowly doled out as the battery ages to make for the appearance of very slow degradation even though the individual raw cells would be wearing out quite a bit faster? If this were true what you would see is after this excess capacity was exhausted would be battery capacity falling off a cliff eventually, though this data seems to show a couple hundred thousand miles of consistent capacity with no cliff.
SSDs do a similar thing for capacity and wear with a sizable proportion of capacity reserved to replace bad blocks as the SSD ages.
Whenever I make this comment almost everyone responding is just guessing about how I'm wrong and new chemistries are so much better, etc.
I think we (sorry I) have seen that degradation has not the concern, it's the pack engineering that is an issue by a large margin.
Tesla's packs first produced in 2017/18 for the model 3 represented largely the industry's first mass produced packs that will largely fail naturally, not due to pack engineering issues (failed cells, leaks, cooling, etc...). Before that required a much higher pack replacement rate, and other manufacturers have the same issues.
Wow, I did not expect anyone to be offering a SIX HUNDRED THOUSAND mile warranty on their batteries. That's some serious confidence. I didn't see anything about it transferring, though. That would be smart on their end - the resale value for electric sports cars at least, is about 50% in the first year, then it levels off hard after that. This would encourage buying new, but not aftermarket. I'll have to look into this.
Still, while this removes a primary concern of mine, there's still one major hurdle that cannot be bypassed as far as I can tell (yet): If you have shared parking, there's essentially no way to charge your car. Maybe if it's an outdoor parking lot you can rely on solar power somewhat, assuming you're in a good situation for that?
Still, my point is that my parking space isn't actually mine, so I can't modify anything in the garage. Assuming superconductors aren't figured out any time soon, this appears to be an impossible solve, which cuts their consumer market significantly.
Also, not exactly the same thing, but they could remove those warranties and instead get some nice replaceable battery cells in there. Let me turn a thing to unlock it, pull out that one cell, and replace it. But maybe I'm a little more wrench-y than their customers want to be?
>> That’s not bad, given that most cars are scrapped somewhere in the 150,000 to 200,000 miles range. At that point, a Tesla will have more than 80% of its initial capacity, and in some cases, even more. So people will probably give up their car, well, well before the battery gets close to becoming a burden.
Can they not see that this is because of correlation and not causation. Why would an EV be given up at 150 - 200K when it has much less moving parts and stressors compared to the traditional ICE based vehicles?
Most important point is comparing it to loss of efficiency in gas cars. There's a lot more variance there, given the work that a gas engine done and all the ways it can be maintained (and lack thereof), but most numbers I've seen point to around 10-15% after 100k miles.
That's just because they don't receive appropriate maintenance. In my family we had plenty of Italian and german cars, we maintained them, most hit 300k+ kilometers. Our 9000$ Lancia Y still worked fine after 350k+ and we only got rid of it because it cannot enter Rome due to emission restrictions.
The study data showing average capacity is helpful, but the lower quartile and even more so the bottom 10% is really what people worry about. In the used car market the presence of even a decidedly small number of “lemons” has a significantly detrimental price impact.
When I bought my Prius in 2010, the longevity of the traction battery was a concern. A month ago, when I finally sold it to a garage, that car had over 190,000 miles on the odometer. I sold it because the transmission needed some repair work. The battery and the engine were still going strong.
I just traded in a 6.5 year old model 3 with 75k miles.
Battery was at 87% of capacity.
The big problem was cold snaps. It had the older heating system and would lose a lot of charge in the cold. Our 2022 Model Y with the newer heating system doesn't lose nearly as much charge in cold snaps.
> At that point, a Tesla will have more than 80% of its initial capacity, and in some cases, even more. So people will probably give up their car, well, well before the battery gets close to becoming a burden.
I looked into the secondhand EV market (in Norway). In doing so I read quite a bit of academic research to figure out the lifetime of an EV. Apparently the 80% capacity is the accepted end of life for an EV battery:
"For batteries, 80% of the initial capacity is referred to as the point after which it tends to exhibit an exponential decay of capacity and is considered an unreliable power source after this point for EV application" [1]
So, the Tesla the article talks about won't be much good, or at least not for very long.
I kind of wonder if the tipping point of "exponential decay" might be where a battery starts being charged and discharged more often to reach daily range and maybe outside the 20-80% window you need for a healthy battery.
In other words, if a battery is new and has 200 miles range, but is driven 100 miles a day, it will stay between 20-80% charge each day when charging.
but at 80% capacity, 160 miles range, it must be either charged above 80% or discharged below 20% each day which is unhealthy for the battery. (either 80%->17% or 83%->20%)
as soon as it starts getting out of healthy range I can see how it can degrade faster.
But cars that stay in that range will have a much longer lifespan.
As another comment mentioned, the cited studies are more about how the battery chemistry changes over time, not how people use the EV. That said, EV manufacturers definitely care about driver habits too, since it affects warranty claims and how they configure their battery management systems.
I think modern EVs are set up to charge to a certain percentage of capacity rather than a specific range, kind of like how smartphones do it.
Your point about depth of discharge ( 80%->17% ) makes sense though, since the battery system can't really control someone's driving routine.
For the comparison to phone batteries, it's worth noting that until the last few years few if any phones allowed capping charge below 100% but now iPhones (15 and higher?), many or all Samsungs and unknown others allow capping for battery health. For the Samsung devices, the ability to do this came somewhere around the time they started promising 5 years of OS and/or security updates.
I'm pretty sure Tesla early on 'sold' an optional range extension that simply allowed you to charge the batteries further for extra range, with part of that cost presumably covering an anticipated higher battery failure rate. IIRC there were also some times when there were hurricanes coming during which they OTA unlocked that for everyone in the affected regions as well to facilitate evacuations.
> Most manufacturers offer a warranty somewhere in the range of 8 to 10 years, and 100,000 miles. That usually means that if your battery is below 70% health within either 8 years or 100,000 miles, they’ll replace it for you.
This disagrees with pretty much every other source I've been able to find. An N year/M mile warranty is good until whichever of N years or M miles you hit first.
Electric owners under-value the last 20% of their battery. That is the most important 20%
If you are running out of "gas" , every lost mile is a mile walking (or being towed). that last 20% of range is the difference between making it to the next charger or being dead on the road. And with electric it's a bigger burden because they can't be refilled with gasoline.
As a practical example, my recent charging forecast dropped from 12% to zero % during the drive (this was controlled for consumption, ambient temps, driving speed etc). We finally arrived with 3% on the battery. So that means in a year, we will not be able to make that exact same drive. That is a problem needing addressed.
I've also not heard great things with the warranties. It seems people struggle to redeem compensation via warranty. And the qualifying conditions are not helpful for most customers experiencing poor performance.
I'm happy with my electric car, but I don't think more of the market will adopt them until this issue is directly addressed. "only 20%" dismisses the most critical and insecure experiences with the car.
I have a cheap 2nd gen Nissan Leaf. It's one of the worst cars for battery degradation since it has no thermal management. I'm in a temperate climate so that helps. After 6 years it's now at about 84% state of health. Not great but it's not catastrophically bad like some anti-EV people will have you believe. I believe the first year experiences the steepest drop in health. Maybe after another 6 years it'll get to 70% and it'll probably get sold to a person who drives shorter distances.
Tbh I'm worrying about everything in my car except for battery degradation.
Inverter dying, charging circuit dying, the motor shorting out, some of the DC isolators going bad, charging port crapping out. Even with the battery, my concern isn't with degradation, but that one of the modules decides call it quits and that's all she wrote.
Also a lot of EV engineering brings to mind the eternal Douglas Adams quote: 'The major difference between a thing that might go wrong and a thing that cannot possibly go wrong is that when a thing that cannot possibly go wrong goes wrong it usually turns out to be impossible to get at or repair.'
All in all, I find the claim that EVs will outlast gasoline vehicles a rather bold and extraordinary claim, and one that won't stand the test of time.
> I’d say that it’s more likely to be the perception of battery degradation that pushes the value down, not the actual degradation in reality.
Why guess? This is data that is almost certainly aggregated back to the manufacturer and could be available as a published report. The fact you don't see this report I think is indicative of the reality.
> Pessimism about battery longevity is giving us all cheaper second-hand EVs
The seller sets the price. Not the buyer. You should ask why the seller is willing to let the vehicle go for a lower than expected price for a given number of miles.
> had lost just 15% of their capacity, on average
There are no average batteries. The used vehicle market doesn't work on averages, it generally works on worst cases, particularly in an as-is (no warranty) sale.
> in other words, there was no active cooling of the battery
As it requires a four way valve. That's a common failure point in EVs.
> Many manufacturers provide long warranties for their batteries
Do those often persist through private party sales?
I'm not trying to be mean, I think EVs are great, but hybrids are still obviously better, and the market is far more complex than this author would like to acknowledge. I dislike articles that start with a conclusion and then spend pages trying to justify it. The data to actually answer this question was available but completely unused here. I did not find this convincing or informative.
Think of it this way. There is a segment of the buying market that is hostile to these vehicles by default. Waving your hands with no data to back it up only makes it worse.
I use my phone instead. Having these apps in the car is like buying a smart TV and having the Netflix and YouTube apps fail after a few years due to changes in the services that the apps can't handle and the manufacturer not providing updates any longer.
I don't know how it is in Europe, but in the US, a long warranty does not necessarily indicate a belief on the manufacturer that the product will last that long.
In many cases warranties are non-transferable (or only partially transferable), so a long warranty could just mean "We think you will sell this before it fails" rather than "We think this will last a long time."
there are electric cars made more than 115 years ago with the original nickle iron batteries that still work, less capacity than lead batteries, but essentialy idestructable and imortal.
there is no reason to equate high power density and low weight with a short life span, and in.the case of capacitive electrical energy storage, we are only waiting for higher energy density, ss it is a true solid state battery, though as every substance that can exist will.hold a charge, the number of possible candidates numbers in the trillions, more, but whatever, and there is an absolute inevitability to creating batteries that will serve humanitys transportation needs.
thousands and thousands of smart people work on that every day.
Old lithium batteries are ticking time bombs. Swelling, leaking, and ready to ignite at the slightest spark or contact with moisture.
As their chemicals break down, one short-circuit can unleash a chain reaction of fire and toxic smoke.
Even sitting forgotten in a drawer, they can suddenly swell, rupture, or explode without warning.
28 comments
[ 1.9 ms ] story [ 37.7 ms ] threadTLDR These batteries are going to outlast the vehicle chassis.
Full Speed Ahead: EV Study Reveals Impacts of Fast Charging - https://news.ycombinator.com/item?id=37330024 - August 2023
https://youtu.be/i31x5JW361k?si=JdjJD_Lzg4qsY84C
That is how much of the battery capacity is hidden by the battery management system when the car is new and then slowly doled out as the battery ages to make for the appearance of very slow degradation even though the individual raw cells would be wearing out quite a bit faster? If this were true what you would see is after this excess capacity was exhausted would be battery capacity falling off a cliff eventually, though this data seems to show a couple hundred thousand miles of consistent capacity with no cliff.
SSDs do a similar thing for capacity and wear with a sizable proportion of capacity reserved to replace bad blocks as the SSD ages.
Whenever I make this comment almost everyone responding is just guessing about how I'm wrong and new chemistries are so much better, etc.
Tesla's packs first produced in 2017/18 for the model 3 represented largely the industry's first mass produced packs that will largely fail naturally, not due to pack engineering issues (failed cells, leaks, cooling, etc...). Before that required a much higher pack replacement rate, and other manufacturers have the same issues.
Still, while this removes a primary concern of mine, there's still one major hurdle that cannot be bypassed as far as I can tell (yet): If you have shared parking, there's essentially no way to charge your car. Maybe if it's an outdoor parking lot you can rely on solar power somewhat, assuming you're in a good situation for that?
Still, my point is that my parking space isn't actually mine, so I can't modify anything in the garage. Assuming superconductors aren't figured out any time soon, this appears to be an impossible solve, which cuts their consumer market significantly.
Also, not exactly the same thing, but they could remove those warranties and instead get some nice replaceable battery cells in there. Let me turn a thing to unlock it, pull out that one cell, and replace it. But maybe I'm a little more wrench-y than their customers want to be?
Can they not see that this is because of correlation and not causation. Why would an EV be given up at 150 - 200K when it has much less moving parts and stressors compared to the traditional ICE based vehicles?
That's just because they don't receive appropriate maintenance. In my family we had plenty of Italian and german cars, we maintained them, most hit 300k+ kilometers. Our 9000$ Lancia Y still worked fine after 350k+ and we only got rid of it because it cannot enter Rome due to emission restrictions.
Battery was at 87% of capacity.
The big problem was cold snaps. It had the older heating system and would lose a lot of charge in the cold. Our 2022 Model Y with the newer heating system doesn't lose nearly as much charge in cold snaps.
What prevents the same advancements from being applied to phone batteries?
I looked into the secondhand EV market (in Norway). In doing so I read quite a bit of academic research to figure out the lifetime of an EV. Apparently the 80% capacity is the accepted end of life for an EV battery:
"For batteries, 80% of the initial capacity is referred to as the point after which it tends to exhibit an exponential decay of capacity and is considered an unreliable power source after this point for EV application" [1]
So, the Tesla the article talks about won't be much good, or at least not for very long.
[1]: https://doi.org/10.1109/ACCESS.2023.3271287
In other words, if a battery is new and has 200 miles range, but is driven 100 miles a day, it will stay between 20-80% charge each day when charging.
but at 80% capacity, 160 miles range, it must be either charged above 80% or discharged below 20% each day which is unhealthy for the battery. (either 80%->17% or 83%->20%)
as soon as it starts getting out of healthy range I can see how it can degrade faster.
But cars that stay in that range will have a much longer lifespan.
I think modern EVs are set up to charge to a certain percentage of capacity rather than a specific range, kind of like how smartphones do it.
Your point about depth of discharge ( 80%->17% ) makes sense though, since the battery system can't really control someone's driving routine.
I'm pretty sure Tesla early on 'sold' an optional range extension that simply allowed you to charge the batteries further for extra range, with part of that cost presumably covering an anticipated higher battery failure rate. IIRC there were also some times when there were hurricanes coming during which they OTA unlocked that for everyone in the affected regions as well to facilitate evacuations.
This disagrees with pretty much every other source I've been able to find. An N year/M mile warranty is good until whichever of N years or M miles you hit first.
If you are running out of "gas" , every lost mile is a mile walking (or being towed). that last 20% of range is the difference between making it to the next charger or being dead on the road. And with electric it's a bigger burden because they can't be refilled with gasoline.
As a practical example, my recent charging forecast dropped from 12% to zero % during the drive (this was controlled for consumption, ambient temps, driving speed etc). We finally arrived with 3% on the battery. So that means in a year, we will not be able to make that exact same drive. That is a problem needing addressed.
I've also not heard great things with the warranties. It seems people struggle to redeem compensation via warranty. And the qualifying conditions are not helpful for most customers experiencing poor performance.
I'm happy with my electric car, but I don't think more of the market will adopt them until this issue is directly addressed. "only 20%" dismisses the most critical and insecure experiences with the car.
Inverter dying, charging circuit dying, the motor shorting out, some of the DC isolators going bad, charging port crapping out. Even with the battery, my concern isn't with degradation, but that one of the modules decides call it quits and that's all she wrote.
Also a lot of EV engineering brings to mind the eternal Douglas Adams quote: 'The major difference between a thing that might go wrong and a thing that cannot possibly go wrong is that when a thing that cannot possibly go wrong goes wrong it usually turns out to be impossible to get at or repair.'
All in all, I find the claim that EVs will outlast gasoline vehicles a rather bold and extraordinary claim, and one that won't stand the test of time.
Why guess? This is data that is almost certainly aggregated back to the manufacturer and could be available as a published report. The fact you don't see this report I think is indicative of the reality.
> Pessimism about battery longevity is giving us all cheaper second-hand EVs
The seller sets the price. Not the buyer. You should ask why the seller is willing to let the vehicle go for a lower than expected price for a given number of miles.
> had lost just 15% of their capacity, on average
There are no average batteries. The used vehicle market doesn't work on averages, it generally works on worst cases, particularly in an as-is (no warranty) sale.
> in other words, there was no active cooling of the battery
As it requires a four way valve. That's a common failure point in EVs.
> Many manufacturers provide long warranties for their batteries
Do those often persist through private party sales?
I'm not trying to be mean, I think EVs are great, but hybrids are still obviously better, and the market is far more complex than this author would like to acknowledge. I dislike articles that start with a conclusion and then spend pages trying to justify it. The data to actually answer this question was available but completely unused here. I did not find this convincing or informative.
Think of it this way. There is a segment of the buying market that is hostile to these vehicles by default. Waving your hands with no data to back it up only makes it worse.
Anyways..
In many cases warranties are non-transferable (or only partially transferable), so a long warranty could just mean "We think you will sell this before it fails" rather than "We think this will last a long time."
Old lithium batteries are ticking time bombs. Swelling, leaking, and ready to ignite at the slightest spark or contact with moisture.
As their chemicals break down, one short-circuit can unleash a chain reaction of fire and toxic smoke. Even sitting forgotten in a drawer, they can suddenly swell, rupture, or explode without warning.