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As an aside, I've been considering an EV as there are some tempting government rebates where I live. One aspect I keep thinking about is battery longevity. Sure

As an aside, I've been considering an EV as there are some tempting government rebates where I live. One aspect I keep thinking about is battery longevity. Sure you might get 1k km out of a brand new battery but what about in 5-10 years? After all, my phone's simple battery is basically done within 5 years and replacing a car's battery sounds like it would be very expensive.

baybal2 5y ago
> Sure you might get 1k km out of a brand new battery but what about in 5-10 years? After all, my phone's simple battery is basically done within 5 years and replacing a car's battery sounds like it would be very expensive. Yep, don't buy into super duper larger batteries. A bigger battery will last longer in cycle life, sure, but the vehicles itself may well be much more expensive. If your EV will survive long enough to see a battery replacement, then a larger battery will be still a worse option economically.
- monkeynotes 5y ago
  Affordability is one thing, but it also sounds like a colossal waste of resources to dispense with these batteries in volume. Gas engines last decades with good maintenance and can be rebuilt. The idea that the modern EV is basically toast (cost prohibitive to repair like all modern electronics) after 5-10 years is not the green future we are trying to work toward. It would be interesting to understand the true environmental impact of EVs.
  - tonyedgecombe 5y ago
    Tesla are talking about million mile batteries in their upcoming cars: https://www.autoexpress.co.uk/tesla/352330/teslas-new-low-cost-long-life-battery-set-2021-launch https://www.autoexpress.co.uk/tesla/352330/teslas-new-low-co... I know they tend to exaggerate but even if its only half that then it will be better than the average ICE car.
    - imtringued 5y ago
      That chemistry is a prerequisite for structural batteries. Replacing a structural battery is obviously not economical.
      - baybal2 5y ago
        You don't necessarily need to have structural battery to be firmly attached to something, nor have it to be housed in some inaccessible compartment. At least, the battery case can support its own weight. This alone can shave up to 100kg from the battery, and make the whole task of engineering it that much easier. This is what all that "blade battery" things is about. Another idea is that if your battery chemistry is not prone to bursting in flames like gasoline, the battery can become a decent crash energy absorber. This way instead of having to add weight to protect the battery, you can use the battery instead to reduce the weight of existing crash protection structures.
  - baybal2 5y ago
    > The idea that the modern EV is basically toast (cost prohibitive to repair like all modern electronics) after 5-10 years is not the green future we are trying to work toward. The current "unrepairability" of today's EV's is nothing inherent to them. There is nothing that prevents Tesla's service centres to repair their cars, say, after collision damage, which they currently refuse to take beyond the most trivial cases. The same goes for other EV brands who say you must scrap your car after borderline cosmetic damage. - Electric motors are inherently more robust than IC engines, and can too be rebuilt with ease if you fry them (which should never really happen when thermal protection, and cooling work as they should.) - Electronics is the least likely part of the electric vehicle to break, and is, again, mostly trivial to repair, or replace. - Cells are the only wear element besides a simple gearbox, and brakes.
  - IcePic 5y ago
    Seems like few people rebuild gas engines in their cars when they become "a few decades old", apart from a _very_ small minority that like retro car stuff. If the battery pack was the only thing needing replacement in EVs and they are possible or even easy to remove/replace, it sounds like it could be done quite easily and still give you a useful vehicle.
  - avianlyric 5y ago
    The batteries are replaceable, so the body of the car won't go to waste. As for the battery, there's still plenty of useful things it can do. Just because it's not useful for a car, doesn't mean it dead. The most obvious use case right now is grid-scale energy storage. There you just need lots and lots of joules of storage, you're not really worried about space or weight (at least compared to car batteries), so it's perfectly viable to take thousands of scrap car batteries with only 60-70% of their original capacity and use them for grid storage. Additionally in grid storage you can be much kinder to your batteries, further extending their life well beyond what they could do in car. At the end of all that, break down the battery and recover the materials. Admittedly we don't have any cost effective ways of doing that today, but as demand for battery raw materials increases, the finical viability of recycling also increases.
  - imtringued 5y ago
    >The idea that the modern EV is basically toast (cost prohibitive to repair like all modern electronics) after 5-10 years is not the green future we are trying to work toward. A 1000km vehicle that lost 90% of its range still has 100km left. I don't see how that vehicle is toast.
throwaway0a5e 5y ago
Automotive batteries have enough reserve they take more like 10yr to degrade. And the degradation is like 10-20%, not 60+% like you get with an end of life laptop battery. The duty cycle that a larger battery charging at home or at work will see is also highly conducive to long life.
belter 5y ago
Its different if you have a charger at home. This is not a Tesla, however it is a realistic view of the current status for some people and some models if we talk about the car experience: https://news.ycombinator.com/item?id=27970913 https://news.ycombinator.com/item?id=27970913 Cannot comment on the main point of your question. Battery duration. Somebody should include that in depreciation calculations concerning car resell value.
wcoenen 5y ago
Phone batteries are typically used very aggressively by charging them to 100% every day. The time spent near 100% causes most of the damage. EVs typically come with a configurable maximum charge limit (e.g. 80% or 90%) which avoids a lot of battery wear.
11thEarlOfMar 5y ago
I've got 85,000/136,000 miles/km on my 2018 Model 3, Long Range. Initial range: 315/500 m/km Updated Range: 325/520 m/km Current Range*: 302/483 m/km *(maximum charge I see when recharging over night) Using the 325 as a starting point, that's 7% decrease in range after 85k/136k m/km. Using 30% decrease as the point where you'd upgrade the battery, and prorating from 7%, you'd drive 360,000/577,000 m/km before needing to replace it. At 18,000/29,000 m/km average annual driving distance, you'd drive 20 years before needing to replace the battery.
- monkeynotes 5y ago
  This is assuming that the deterioration rate is linear, I have no idea if that is true. But if these numbers are accurate the longevity is better than expected. Scrapping these batteries in volume is another challenge. I imagine in 10 years today's battery tech will be obsolete. I am still on the fence about getting into an EV, it still appears to be an early adopter technology.
  - 11thEarlOfMar 5y ago
    It appears to not be linear, based on the data entered by the Dutch Tesla Motors Club, see the chart near the bottom: https://www.bloomberg.com/graphics/2019-tesla-model-3-survey/customer-service-battery.html https://www.bloomberg.com/graphics/2019-tesla-model-3-survey...
  - kthejoker2 5y ago
    > I imagine in 10 years today's battery tech will be obsolete. What's your basis for this? Battery tech has largely been incrementalist for the past decade, are there specific breakthroughs you're watching?
    - monkeynotes 5y ago
      Solid state batteries: https://en.wikipedia.org/wiki/Solid-state_battery https://en.wikipedia.org/wiki/Solid-state_battery
- 5y ago
Rygian 5y ago
Tesla cars are initially sold with an 8-year or X km warranty that the battery will hold at least 70% of the design energy. (The X km is between 160000 and 240000 km, depending on the size of the battery.) Also, my personal expectation is that a larger capacity means the wear is distributed across a larger number of cells, leading to increased life expectancy. This assumption fits with the warranty policy of Tesla.
baldeagle 5y ago
Range deterioration is an issue for uncooled batteries in hot climates. For example, gen 1 Nissan leafs were suffering in Arizona. But most everyone else uses active cool, which really slows the degradation. You can't really apply small battery (cellphone) logic to something as large as a car battery.
castlecrasher2 5y ago
Some cars/brands have much worse battery life. The Nissan Leaf is notoriously awful for this, unless they've fixed it. Tesla is great, and the Chevy Bolt (which I own one, love it) retains most of its battery life over time.
imtringued 5y ago
Phones cook their batteries and discharge them all the way to from 100% to 0%. It's literally battery torture.
fulafel 5y ago
> After all, my phone's simple battery is basically done within 5 years It's a design parameter for the battery and its management system. Basically lithium ion battery lifetime is a function of what you cap the charge at. If the battery design sets the "100%" point in the BMS close to the chemistry's max capacity, you will get a low number of charge cycles. Phones have a shorter design lifetime than cars and make more aggressive compromises towards lower size and weight.

baybal2 5y ago

> Sure you might get 1k km out of a brand new battery but what about in 5-10 years? After all, my phone's simple battery is basically done within 5 years and replacing a car's battery sounds like it would be very expensive. Yep, don't buy into super duper larger batteries. A bigger battery will last longer in cycle life, sure, but the vehicles itself may well be much more expensive. If your EV will survive long enough to see a battery replacement, then a larger battery will be still a worse option economically.

monkeynotes 5y ago
Affordability is one thing, but it also sounds like a colossal waste of resources to dispense with these batteries in volume. Gas engines last decades with good maintenance and can be rebuilt. The idea that the modern EV is basically toast (cost prohibitive to repair like all modern electronics) after 5-10 years is not the green future we are trying to work toward. It would be interesting to understand the true environmental impact of EVs.
- tonyedgecombe 5y ago
  Tesla are talking about million mile batteries in their upcoming cars: https://www.autoexpress.co.uk/tesla/352330/teslas-new-low-cost-long-life-battery-set-2021-launch https://www.autoexpress.co.uk/tesla/352330/teslas-new-low-co... I know they tend to exaggerate but even if its only half that then it will be better than the average ICE car.
  - imtringued 5y ago
    That chemistry is a prerequisite for structural batteries. Replacing a structural battery is obviously not economical.
    - baybal2 5y ago
      You don't necessarily need to have structural battery to be firmly attached to something, nor have it to be housed in some inaccessible compartment. At least, the battery case can support its own weight. This alone can shave up to 100kg from the battery, and make the whole task of engineering it that much easier. This is what all that "blade battery" things is about. Another idea is that if your battery chemistry is not prone to bursting in flames like gasoline, the battery can become a decent crash energy absorber. This way instead of having to add weight to protect the battery, you can use the battery instead to reduce the weight of existing crash protection structures.
- baybal2 5y ago
  > The idea that the modern EV is basically toast (cost prohibitive to repair like all modern electronics) after 5-10 years is not the green future we are trying to work toward. The current "unrepairability" of today's EV's is nothing inherent to them. There is nothing that prevents Tesla's service centres to repair their cars, say, after collision damage, which they currently refuse to take beyond the most trivial cases. The same goes for other EV brands who say you must scrap your car after borderline cosmetic damage. - Electric motors are inherently more robust than IC engines, and can too be rebuilt with ease if you fry them (which should never really happen when thermal protection, and cooling work as they should.) - Electronics is the least likely part of the electric vehicle to break, and is, again, mostly trivial to repair, or replace. - Cells are the only wear element besides a simple gearbox, and brakes.
- IcePic 5y ago
  Seems like few people rebuild gas engines in their cars when they become "a few decades old", apart from a _very_ small minority that like retro car stuff. If the battery pack was the only thing needing replacement in EVs and they are possible or even easy to remove/replace, it sounds like it could be done quite easily and still give you a useful vehicle.
- avianlyric 5y ago
  The batteries are replaceable, so the body of the car won't go to waste. As for the battery, there's still plenty of useful things it can do. Just because it's not useful for a car, doesn't mean it dead. The most obvious use case right now is grid-scale energy storage. There you just need lots and lots of joules of storage, you're not really worried about space or weight (at least compared to car batteries), so it's perfectly viable to take thousands of scrap car batteries with only 60-70% of their original capacity and use them for grid storage. Additionally in grid storage you can be much kinder to your batteries, further extending their life well beyond what they could do in car. At the end of all that, break down the battery and recover the materials. Admittedly we don't have any cost effective ways of doing that today, but as demand for battery raw materials increases, the finical viability of recycling also increases.
- imtringued 5y ago
  >The idea that the modern EV is basically toast (cost prohibitive to repair like all modern electronics) after 5-10 years is not the green future we are trying to work toward. A 1000km vehicle that lost 90% of its range still has 100km left. I don't see how that vehicle is toast.

throwaway0a5e 5y ago

Automotive batteries have enough reserve they take more like 10yr to degrade. And the degradation is like 10-20%, not 60+% like you get with an end of life laptop battery. The duty cycle that a larger battery charging at home or at work will see is also highly conducive to long life.

belter 5y ago

Its different if you have a charger at home. This is not a Tesla, however it is a realistic view of the current status for some people and some models if we talk about the car experience: https://news.ycombinator.com/item?id=27970913 https://news.ycombinator.com/item?id=27970913 Cannot comment on the main point of your question. Battery duration. Somebody should include that in depreciation calculations concerning car resell value.

wcoenen 5y ago

Phone batteries are typically used very aggressively by charging them to 100% every day. The time spent near 100% causes most of the damage. EVs typically come with a configurable maximum charge limit (e.g. 80% or 90%) which avoids a lot of battery wear.

11thEarlOfMar 5y ago

I've got 85,000/136,000 miles/km on my 2018 Model 3, Long Range. Initial range: 315/500 m/km Updated Range: 325/520 m/km Current Range*: 302/483 m/km *(maximum charge I see when recharging over night) Using the 325 as a starting point, that's 7% decrease in range after 85k/136k m/km. Using 30% decrease as the point where you'd upgrade the battery, and prorating from 7%, you'd drive 360,000/577,000 m/km before needing to replace it. At 18,000/29,000 m/km average annual driving distance, you'd drive 20 years before needing to replace the battery.

monkeynotes 5y ago
This is assuming that the deterioration rate is linear, I have no idea if that is true. But if these numbers are accurate the longevity is better than expected. Scrapping these batteries in volume is another challenge. I imagine in 10 years today's battery tech will be obsolete. I am still on the fence about getting into an EV, it still appears to be an early adopter technology.
- 11thEarlOfMar 5y ago
  It appears to not be linear, based on the data entered by the Dutch Tesla Motors Club, see the chart near the bottom: https://www.bloomberg.com/graphics/2019-tesla-model-3-survey/customer-service-battery.html https://www.bloomberg.com/graphics/2019-tesla-model-3-survey...
- kthejoker2 5y ago
  > I imagine in 10 years today's battery tech will be obsolete. What's your basis for this? Battery tech has largely been incrementalist for the past decade, are there specific breakthroughs you're watching?
  - monkeynotes 5y ago
    Solid state batteries: https://en.wikipedia.org/wiki/Solid-state_battery https://en.wikipedia.org/wiki/Solid-state_battery
5y ago

Rygian 5y ago

Tesla cars are initially sold with an 8-year or X km warranty that the battery will hold at least 70% of the design energy. (The X km is between 160000 and 240000 km, depending on the size of the battery.) Also, my personal expectation is that a larger capacity means the wear is distributed across a larger number of cells, leading to increased life expectancy. This assumption fits with the warranty policy of Tesla.

baldeagle 5y ago

Range deterioration is an issue for uncooled batteries in hot climates. For example, gen 1 Nissan leafs were suffering in Arizona. But most everyone else uses active cool, which really slows the degradation. You can't really apply small battery (cellphone) logic to something as large as a car battery.

castlecrasher2 5y ago

Some cars/brands have much worse battery life. The Nissan Leaf is notoriously awful for this, unless they've fixed it. Tesla is great, and the Chevy Bolt (which I own one, love it) retains most of its battery life over time.

imtringued 5y ago

Phones cook their batteries and discharge them all the way to from 100% to 0%. It's literally battery torture.

fulafel 5y ago

> After all, my phone's simple battery is basically done within 5 years It's a design parameter for the battery and its management system. Basically lithium ion battery lifetime is a function of what you cap the charge at. If the battery design sets the "100%" point in the BMS close to the chemistry's max capacity, you will get a low number of charge cycles. Phones have a shorter design lifetime than cars and make more aggressive compromises towards lower size and weight.