6 ms·

> 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 be

> 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. [1]: https://doi.org/10.1109/ACCESS.2023.3271287 https://doi.org/10.1109/ACCESS.2023.3271287

bryanlarsen 1y ago
That's statistical. A small number will start their exponential degrade at 80%, but most won't. Some might get to 60% before they start it. So if you're at 83% at 200,000 miles you don't really know whether you have 50,000 more or you have 200,000 more on the battery. And "exponential degrade" doesn't mean it's particularly fast. It means it's faster to degrade from 80 to 60 than it is from 100 to 80. You're not going to get 500,000 miles out of driving until the battery hits 60% but you might get a substantial fraction. The rest of the car almost certainly doesn't have 200,000 more miles in it, so who cares?
- _carbyau_ 1y ago
  > The rest of the car almost certainly doesn't have 200,000 more miles in it, so who cares? This what I find curious. It used to be cars were largely limited by their main driveline components. Now those components have been simplified. In a lot of the BYD cars it is literally the exact same driveline so for them it is almost commoditised. My part of the world sees no snow or salt. So if the body is fine and the driveline is fine.... Why can't I run a car for a million miles and simply replace coils, struts, hubs, bearings, carpets, seats, the-tiny-electric-motors-that-drive-windows-and-seats-and-mirrors etc? IE where is the electric version of the old landcruiser series?
  - lelandbatey 1y ago
    That's just "any electric car" as long as you're willing to replace the battery. Since the only thing in the drive train that moves is the electric motors (and contactors), any EV is way more mechanically simple than any internal combustion car. The non reliable stuff is all the OTHER wiring/screen/software.
- sidewndr46 1y ago
  Why do you think a vehicle with 200,000 miles on it doesn't have 200,000 more miles in most of the components? It isn't remotely difficult to imagine that being possible. One of my ICE vehicles was 299,648 miles when a component in the transmission gave out. The only reason I didn't repair it was around a decade earlier someone had bent the frame. If I had been willing to replace that part, I would still be driving it today. People replace vehicles because they want and can afford replacement ones, not because they are mileage limited.
  - giardini 1y ago
    sidewndr46 says " One of my ICE vehicles was 299,648 miles when a component in the transmission gave out." I'm guessing it was a Lexus?
  - extraisland 1y ago
    > People replace vehicles because they want and can afford replacement ones, not because they are mileage limited. That isn't quite true. It is often because it is uneconomical to keep. The issue with many older vehicles is that it just starts costing more to repair it than the car is worth. You are constantly putting in good money, after bad and the the costs keep going up over time. At that point it is often better to buy another vehicle. I could have kept my 2007 Vauxhall Astra going for another 100,000 miles. The issue is that the car was worth £600-1000. Each repair was costing upwards of £300. I could buy another second hand Vauxhall Astra with the amount of money I was spending on the car yearly. It just wasn't worth it.
    - sidewndr46 1y ago
      This is just a bad application of sunk cost. The reason why you spend 300 pounds to repair a 1000 pound car is because it is a known item. If you buy a used one for 600 pounds, it may need even more repair than the one you already have.
      - extraisland 1y ago
        Repairing a known item makes sense when the costs are small compared to a replacement. I have old bicycles that are worth nothing and I am quite happy to spend maybe £50-£150 in components to fix. Costs are much lower than buying a new good bike or trying to find another good second hand bike (which I would need to fix anyway). However that frequently isn't the case with car. It is £300-1000 every time I need to get it repaired. This happens at an increasing frequency as the car ages. This can then add up to several 1000s quite easily. e.g In the last year I owned that Astra I had to to fix the following issue (all costs include labour): - New Clutch (and it needed to be towed to the garage as the clutch wouldn't engage). £1000 for clutch replacement, £150 for the tow. I also needed to rent a car to drive to a funeral. That cost me another £100-200 IIRC. So we we are up to £1350. - Car would randomly go into Limp mode. New sensor cost £300. Vehicle was never really fixed. It just went into Limp mode much less, so there was another problem somewhere. Which would need another trip to the garage. - Service. This flagged several issues with the car. All these small repairs was another £800. I am already upto £2,450 and I know I've forgotten stuff. I bought the car for £4000 originally. If it was something like a classic barn on wheels Volvo which are bullet proof, or a classic Rover like a Rover P5. I might be willing to keep dumping money into it. But it isn't, it is a Vauxhall Astra.
- sleepyguy 1y ago
  I drive my vehicles for 300-500k miles. The drive train should be the only thing that wears out and that can be replaced with used drive trains from a wrecking yard.
  - cloverich 1y ago
    What are your breakdown patterns ands how do you go about defending / being prepared? I bet you have a lot of useful advice.
    - dzhiurgis 1y ago
      He’d answer but he’s busy driving
      - sleepyguy 1y ago
        Every vehicle comes with a service schedule. If you know nothing about maintaining or repairing a vehicle, follow what it suggests (it's in your glove box). It might cost more in the short term but save you more in the long term. A friend does that and his vehicles last forever and reach crazy millage (he drives a lot as a regional sales manager).
    - deleted 1y ago
      [deleted]
    - Ancapistani 1y ago
      Not the GP, but I can answer. My current vehicle is 35 years old. Prior to that, I had a '00 Jeep Wrangler for 15 years. Before that was a selection of older vehicles: an '88 Toyota pickup (that I dearly miss...), a '97 Ford Ranger, a '99 Dodge Dakota, and a '98 Honda Accord. I keep a small toolbox in my vehicle. It's mostly inexpensive hand tools, but I include a Milwaukee M18 Fuel impact and a set of sockets for it - super handy for changing tires. In my 25 years of driving, I've broken down probably a dozen times total. Of those, only twice have I required a tow - and one of those was in my wife's Kia Sorento, which we bought new. Easily 90% of the usage of the tools I carry ends up being on other people's vehicles. I can swap a wheel on the side of the road in <10m with a bottle jack and a battery-powered impact, with no real manual labor involved. Other breakdowns I've had in the past were things like the serpentine belt breaking or a coolant hose coming loose. Those are five minute fixes if you have access to a parts store. When the belt snapped on my Jeep in the middle of the night on a trip a few years ago, I used an pair of my wife's leggings that she had packed to get us home. I just tied them by hand, bypassed all the non-essential stuff on the motor, and drove the ~50 miles back home to deal with it the next day.
- cicko 1y ago
  I recently drove in an early Tesla with over 400K kilometers on the clock. Still runs quite fine and the range seems longer than my Zoe's.
- starwatch 1y ago
  > That's statistical. A small number will start their exponential degrade at 80%, but most won't. Some might get to 60% before they start it. The paper that underpins the 80% claim is paywalled and I'm cheap so don't have the numbers to hand. But in the abstract sense being statistical could go the other way too - i.e. some might get to 90% before they start their exponential decay. > And "exponential degrade" doesn't mean it's particularly fast. True, exponential doesn't mean much other than e^n where it's implied that n > 1. However the value of n does matter, for example a decay rate for n=100 is quite different than n=1.1. Again, we're talking in general terms as I don't have the value of n for this. For better or worse, I'm taking the paper at face value when it talks of end of life at 80% - however it has been peer reviewed and is in a "proper" journal so to my mind that adds some credibility. It's worth mentioning that the current DoE guidance on lifetimes is: "12 to 15 years in moderate climates (8 to 12 years in extreme climates)". Of course that guidance is also based on a statistical analysis that doesn't seem to account for modern battery management systems [1]. There are additional factors at play that govern battery degradation, including things like: battery chemistry, environment, EV charging habits, etc. Ultimately the real test of EV battery life will come with time. It'll manifest as the change in average age of scrapped vehicles with large fleets of EV's on the road. In Norway right now it's about 18 years (for a mostly internal combustion fleet) [2]. However as of this year all private vehicles sold must be zero-emission - so in 10-20 years we'll have some interesting data [3]. [1]: https://web.archive.org/web/20250530000446/https://afdc.energy.gov/fuels/electricity-benefits https://web.archive.org/web/20250530000446/https://afdc.ener... [2]: https://www.ssb.no/en/statbank/table/05522/tableViewLayout1/?loadedQueryId=10111972&timeType=item https://www.ssb.no/en/statbank/table/05522/tableViewLayout1/... [3]: https://web.archive.org/web/20250530115356/https://www.regjeringen.no/contentassets/aaee20cf5a9e468ea97fd51638c42407/en-gb/pdfs/stm202320240014000engpdfs.pdf https://web.archive.org/web/20250530115356/https://www.regje...
  - starwatch 1y ago
    Edit: It'll manifest as the change in average age of scrapped vehicles [in countries] with large fleets of EV's on the road.
foobazgt 1y ago
> For batteries, 80% of the initial capacity is referred to as the point The publication cites sources from 15 years ago for this "fact" [0]. That's ancient history in the context of EVs (even before the first reliable mass production EV - Tesla's Model S - was initially released). As a practical matter, the article points out that most EV manufacturers (Tesla included) warranty their batteries for at least 70% capacity at timespans near a decade, which would bankrupt them all if EV batteries just up and died at 80%. 0) [35] O. Erdinc, B. Vural, and M. Uzunoglu, ‘‘A dynamic lithium-ion battery model considering the effects of temperature and capacity fading,’’ in Proc. Int. Conf. Clean Electr. Power, Jun. 2009, pp. 383–386. [36] K. Smith, T. Markel, G.-H. Kim, and A. Pesaran, ‘‘Design of electric drive vehicle batteries for long life and low cost,’’ in Proc. Accelerated Stress Test. Rel. (ASTR), IEE Workshop, 2010, pp. 6–8.
- starwatch 1y ago
  It is an older paper, though that in itself isn't a reason to discount this (or any science). For example, the DoE still uses an 2014 predictive model to estimate longevity of today's EV batteries at "12 to 15 years in moderate climates (8 to 12 years in extreme climates)" [1]. However as the DoE says, battery longevity depends on a bunch of factors e.g. chemistry, charging patterns, etc. To the practical matter - yes, EV manufacturers are very careful with warranty periods. Anecdotally, an acquaintance had a Tesla for 8 years. 6 months after the 8-year battery warranty expired the battery ceased working. The details were a little unclear (it was explained in broken English/Norwegian). That said, anecdata carries little weight. What we need is more peer-reviewed research to update our understanding of battery longevity. Until we have that we need to rely on the existing published knowledge... otherwise anyone can assert anything and we learn nothing. [1]: https://web.archive.org/web/20250530000446/https://afdc.energy.gov/fuels/electricity-benefits https://web.archive.org/web/20250530000446/https://afdc.ener...
m463 1y ago
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.
- starwatch 1y ago
  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.

bryanlarsen 1y ago

That's statistical. A small number will start their exponential degrade at 80%, but most won't. Some might get to 60% before they start it. So if you're at 83% at 200,000 miles you don't really know whether you have 50,000 more or you have 200,000 more on the battery. And "exponential degrade" doesn't mean it's particularly fast. It means it's faster to degrade from 80 to 60 than it is from 100 to 80. You're not going to get 500,000 miles out of driving until the battery hits 60% but you might get a substantial fraction. The rest of the car almost certainly doesn't have 200,000 more miles in it, so who cares?

_carbyau_ 1y ago
> The rest of the car almost certainly doesn't have 200,000 more miles in it, so who cares? This what I find curious. It used to be cars were largely limited by their main driveline components. Now those components have been simplified. In a lot of the BYD cars it is literally the exact same driveline so for them it is almost commoditised. My part of the world sees no snow or salt. So if the body is fine and the driveline is fine.... Why can't I run a car for a million miles and simply replace coils, struts, hubs, bearings, carpets, seats, the-tiny-electric-motors-that-drive-windows-and-seats-and-mirrors etc? IE where is the electric version of the old landcruiser series?
- lelandbatey 1y ago
  That's just "any electric car" as long as you're willing to replace the battery. Since the only thing in the drive train that moves is the electric motors (and contactors), any EV is way more mechanically simple than any internal combustion car. The non reliable stuff is all the OTHER wiring/screen/software.
sidewndr46 1y ago
Why do you think a vehicle with 200,000 miles on it doesn't have 200,000 more miles in most of the components? It isn't remotely difficult to imagine that being possible. One of my ICE vehicles was 299,648 miles when a component in the transmission gave out. The only reason I didn't repair it was around a decade earlier someone had bent the frame. If I had been willing to replace that part, I would still be driving it today. People replace vehicles because they want and can afford replacement ones, not because they are mileage limited.
- giardini 1y ago
  sidewndr46 says " One of my ICE vehicles was 299,648 miles when a component in the transmission gave out." I'm guessing it was a Lexus?
- extraisland 1y ago
  > People replace vehicles because they want and can afford replacement ones, not because they are mileage limited. That isn't quite true. It is often because it is uneconomical to keep. The issue with many older vehicles is that it just starts costing more to repair it than the car is worth. You are constantly putting in good money, after bad and the the costs keep going up over time. At that point it is often better to buy another vehicle. I could have kept my 2007 Vauxhall Astra going for another 100,000 miles. The issue is that the car was worth £600-1000. Each repair was costing upwards of £300. I could buy another second hand Vauxhall Astra with the amount of money I was spending on the car yearly. It just wasn't worth it.
  - sidewndr46 1y ago
    This is just a bad application of sunk cost. The reason why you spend 300 pounds to repair a 1000 pound car is because it is a known item. If you buy a used one for 600 pounds, it may need even more repair than the one you already have.
    - extraisland 1y ago
      Repairing a known item makes sense when the costs are small compared to a replacement. I have old bicycles that are worth nothing and I am quite happy to spend maybe £50-£150 in components to fix. Costs are much lower than buying a new good bike or trying to find another good second hand bike (which I would need to fix anyway). However that frequently isn't the case with car. It is £300-1000 every time I need to get it repaired. This happens at an increasing frequency as the car ages. This can then add up to several 1000s quite easily. e.g In the last year I owned that Astra I had to to fix the following issue (all costs include labour): - New Clutch (and it needed to be towed to the garage as the clutch wouldn't engage). £1000 for clutch replacement, £150 for the tow. I also needed to rent a car to drive to a funeral. That cost me another £100-200 IIRC. So we we are up to £1350. - Car would randomly go into Limp mode. New sensor cost £300. Vehicle was never really fixed. It just went into Limp mode much less, so there was another problem somewhere. Which would need another trip to the garage. - Service. This flagged several issues with the car. All these small repairs was another £800. I am already upto £2,450 and I know I've forgotten stuff. I bought the car for £4000 originally. If it was something like a classic barn on wheels Volvo which are bullet proof, or a classic Rover like a Rover P5. I might be willing to keep dumping money into it. But it isn't, it is a Vauxhall Astra.
sleepyguy 1y ago
I drive my vehicles for 300-500k miles. The drive train should be the only thing that wears out and that can be replaced with used drive trains from a wrecking yard.
- cloverich 1y ago
  What are your breakdown patterns ands how do you go about defending / being prepared? I bet you have a lot of useful advice.
  - dzhiurgis 1y ago
    He’d answer but he’s busy driving
    - sleepyguy 1y ago
      Every vehicle comes with a service schedule. If you know nothing about maintaining or repairing a vehicle, follow what it suggests (it's in your glove box). It might cost more in the short term but save you more in the long term. A friend does that and his vehicles last forever and reach crazy millage (he drives a lot as a regional sales manager).
  - deleted 1y ago
    [deleted]
  - Ancapistani 1y ago
    Not the GP, but I can answer. My current vehicle is 35 years old. Prior to that, I had a '00 Jeep Wrangler for 15 years. Before that was a selection of older vehicles: an '88 Toyota pickup (that I dearly miss...), a '97 Ford Ranger, a '99 Dodge Dakota, and a '98 Honda Accord. I keep a small toolbox in my vehicle. It's mostly inexpensive hand tools, but I include a Milwaukee M18 Fuel impact and a set of sockets for it - super handy for changing tires. In my 25 years of driving, I've broken down probably a dozen times total. Of those, only twice have I required a tow - and one of those was in my wife's Kia Sorento, which we bought new. Easily 90% of the usage of the tools I carry ends up being on other people's vehicles. I can swap a wheel on the side of the road in <10m with a bottle jack and a battery-powered impact, with no real manual labor involved. Other breakdowns I've had in the past were things like the serpentine belt breaking or a coolant hose coming loose. Those are five minute fixes if you have access to a parts store. When the belt snapped on my Jeep in the middle of the night on a trip a few years ago, I used an pair of my wife's leggings that she had packed to get us home. I just tied them by hand, bypassed all the non-essential stuff on the motor, and drove the ~50 miles back home to deal with it the next day.
cicko 1y ago
I recently drove in an early Tesla with over 400K kilometers on the clock. Still runs quite fine and the range seems longer than my Zoe's.
starwatch 1y ago
> That's statistical. A small number will start their exponential degrade at 80%, but most won't. Some might get to 60% before they start it. The paper that underpins the 80% claim is paywalled and I'm cheap so don't have the numbers to hand. But in the abstract sense being statistical could go the other way too - i.e. some might get to 90% before they start their exponential decay. > And "exponential degrade" doesn't mean it's particularly fast. True, exponential doesn't mean much other than e^n where it's implied that n > 1. However the value of n does matter, for example a decay rate for n=100 is quite different than n=1.1. Again, we're talking in general terms as I don't have the value of n for this. For better or worse, I'm taking the paper at face value when it talks of end of life at 80% - however it has been peer reviewed and is in a "proper" journal so to my mind that adds some credibility. It's worth mentioning that the current DoE guidance on lifetimes is: "12 to 15 years in moderate climates (8 to 12 years in extreme climates)". Of course that guidance is also based on a statistical analysis that doesn't seem to account for modern battery management systems [1]. There are additional factors at play that govern battery degradation, including things like: battery chemistry, environment, EV charging habits, etc. Ultimately the real test of EV battery life will come with time. It'll manifest as the change in average age of scrapped vehicles with large fleets of EV's on the road. In Norway right now it's about 18 years (for a mostly internal combustion fleet) [2]. However as of this year all private vehicles sold must be zero-emission - so in 10-20 years we'll have some interesting data [3]. [1]: https://web.archive.org/web/20250530000446/https://afdc.energy.gov/fuels/electricity-benefits https://web.archive.org/web/20250530000446/https://afdc.ener... [2]: https://www.ssb.no/en/statbank/table/05522/tableViewLayout1/?loadedQueryId=10111972&timeType=item https://www.ssb.no/en/statbank/table/05522/tableViewLayout1/... [3]: https://web.archive.org/web/20250530115356/https://www.regjeringen.no/contentassets/aaee20cf5a9e468ea97fd51638c42407/en-gb/pdfs/stm202320240014000engpdfs.pdf https://web.archive.org/web/20250530115356/https://www.regje...
- starwatch 1y ago
  Edit: It'll manifest as the change in average age of scrapped vehicles [in countries] with large fleets of EV's on the road.

foobazgt 1y ago

> For batteries, 80% of the initial capacity is referred to as the point The publication cites sources from 15 years ago for this "fact" [0]. That's ancient history in the context of EVs (even before the first reliable mass production EV - Tesla's Model S - was initially released). As a practical matter, the article points out that most EV manufacturers (Tesla included) warranty their batteries for at least 70% capacity at timespans near a decade, which would bankrupt them all if EV batteries just up and died at 80%. 0) [35] O. Erdinc, B. Vural, and M. Uzunoglu, ‘‘A dynamic lithium-ion battery model considering the effects of temperature and capacity fading,’’ in Proc. Int. Conf. Clean Electr. Power, Jun. 2009, pp. 383–386. [36] K. Smith, T. Markel, G.-H. Kim, and A. Pesaran, ‘‘Design of electric drive vehicle batteries for long life and low cost,’’ in Proc. Accelerated Stress Test. Rel. (ASTR), IEE Workshop, 2010, pp. 6–8.

starwatch 1y ago
It is an older paper, though that in itself isn't a reason to discount this (or any science). For example, the DoE still uses an 2014 predictive model to estimate longevity of today's EV batteries at "12 to 15 years in moderate climates (8 to 12 years in extreme climates)" [1]. However as the DoE says, battery longevity depends on a bunch of factors e.g. chemistry, charging patterns, etc. To the practical matter - yes, EV manufacturers are very careful with warranty periods. Anecdotally, an acquaintance had a Tesla for 8 years. 6 months after the 8-year battery warranty expired the battery ceased working. The details were a little unclear (it was explained in broken English/Norwegian). That said, anecdata carries little weight. What we need is more peer-reviewed research to update our understanding of battery longevity. Until we have that we need to rely on the existing published knowledge... otherwise anyone can assert anything and we learn nothing. [1]: https://web.archive.org/web/20250530000446/https://afdc.energy.gov/fuels/electricity-benefits https://web.archive.org/web/20250530000446/https://afdc.ener...

m463 1y ago

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.

starwatch 1y ago
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.