6 ms·

"lithium-ion batteries .. degrade after just 1,000 cycles" If you charge your car battery twice a week and complete a full cycle then we are still talking about

by mrabcx 2y ago

"lithium-ion batteries .. degrade after just 1,000 cycles" If you charge your car battery twice a week and complete a full cycle then we are still talking about like 9 years to reach 1000 cycles. If you charge your phone every day, and do a full cycle, then we are close to 2.7 years. But you will probably not do a full cycle. So, I guess lithium-ion batteries are not really that bad.

hackingonempty 2y ago
Don't forget calendar life. Lithium batteries degrade over time even if you do not cycle them. The life of the commonly used chemistries is only around 3 years.
- r00fus 2y ago
  Explain my 7.5 year old EV with 95% battery health and 65k miles driven? Your 2nd sentence has issues with reality.
  - DylanDmitri 2y ago
    Some EVs start with capacity “gated off” to limit the depth of early cycles and provide a more graceful degradation.
    - r00fus 2y ago
      But a lifetime of 3y doesn't jive with why my 7 year old vehicle is mostly fully functional. Even with 10% over-provisioning (amazingly expensive 7y ago), that's only a 15% reduction in 7 years. The statement "The life of the commonly used chemistries is only around 3 years" is completely misleading and probably inaccurate.
      - freedomben 2y ago
        I don't know about the 3 years number, but generally speaking battery lives are estimates/averages based on statistics. If you have a battery that was well cared for it will outperform the average. Also sometimes it's just dumb luck. One aberration isn't nearly enough data to throw out the entire premise
  - saidinesh5 2y ago
    It depends on your usage too, along with the exact chemistry and form factor of the lithium battery. A lot of people report lithium batteries swelling up in their phones/tablets around 3-4 years of usage.
    - mapt 2y ago
      Phone batteries are lithium polymer pouch cells, the least durable type commonly used. Car cells with lithium ion NMC cylindrical cells are much better, and LIFEPO4 in turn is several times more durable than that. You would be wise to insist on an EV with LIFEPO4 batteries in the sense that calendar lifetimes are more likely to be on par with traditional engines.
  - kccqzy 2y ago
    The explanation is simple. OP said commonly used chemistries. That would be something like LCO. Your EV battery is probably NMC.
    - r00fus 2y ago
      NMC is the most commonly used battery chemistry in the US for EVs which is what this thread was all about.
- api 2y ago
  Degrade to what extent? I have a 12 year old Nissan Leaf that's lost maybe 25% of its range. Still absolutely usable as a neighborhood car.
  - fredrikholm 2y ago
    > neighborhood car Not familiar with that term, what does it mean? Shared ride? A car for walking distances?
    - globular-toast 2y ago
      An electric wheelchair.
    - BobaFloutist 2y ago
      I think they mean "city car" as opposed to "road trip car" or "rural car."
    - Cupprum 2y ago
      Going to work, groceries and so on, the regular stuff. If the city was walkable, you would not need such a thing as neighborhood car, you could just use a bike, but apparently as a society at many places we have decided that the cars are the best mode of transportation ever.
  - neogodless 2y ago
    A 2013 Nissan Leaf should get 60-75 miles of range (depending on how much of thebattery you use, as well as climate, and other driving conditions). If it got ~80 miles new, it would still get 60 miles now. That might be enough for someone to make a short commute, though unless they have relatively fast charging at home, a 20+ mile commute 5 days a week might be tough to pull off. But most errands would fall well within the existing / remaining range.
    - chgs 2y ago
      50 mile round trip at 3 miles per kWh would be under 20kWh, or 1.6kW for 12 hours, about the same as a plug in heater on max, easily doable in a normal socket let alone a dedicated charge circuit.
tecleandor 2y ago
But it could be very interesting for commercial or industrial use: commercial vehicles that are constantly driven and charged, power reserve batteries, tools... And I guess that you could make devices with smaller batteries and fast charge, with less fear of wearing them early.
WaltYoder 2y ago
For grid-level solar energy, we will need batteries that cycle at least 200 times per year. A system that requires replacing batteries every 5 years can't really be described as "renewable energy".
- gpm 2y ago
  As long as "replace" includes "take the old batteries and turn them into raw materials for making new batteries" it definitely can. Typical issues with old batteries are things like dendrite growth. There's nothing wrong with the materials that went into making the battery, they've just reshaped themselves into an unfortunate spiky structure.
flowerthoughts 2y ago
Note that LiFePO/LFP batteries used in cars and large installations are rated for 5,000+ cycles. They really are on another level compared to Li-Co phone batteries that top out at 1,000.
nomel 2y ago
Most EV map displayed 0% to 100% to something like physical 5% to 95%, or even more extreme, to help.
magicalhippo 2y ago
There's also some research[1] suggesting that dynamic cycling extends lithium-ion battery life, compared to the fixed charge/discharge cycles typically done in a lab setting. In this study, we systematically compared dynamic discharge profiles representative of electric vehicle driving to the well-accepted constant current profiles. Surprisingly, we found that dynamic discharge enhances lifetime substantially compared with constant current discharge. Specifically, for the same average current and voltage window, varying the dynamic discharge profile led to an increase of up to 38% in equivalent full cycles at end of life. [1]: https://www.nature.com/articles/s41560-024-01675-8 https://www.nature.com/articles/s41560-024-01675-8
kylehotchkiss 2y ago
We even lived to see lithium ion batteries redefine what battery powered devices can even do! I remember my parents first Dell laptop with a whopping 2 hour battery life, if you weren’t doing anything processor intensive, otherwise it was basically a UPS.

by mrabcx 2y ago

hackingonempty 2y ago

Don't forget calendar life. Lithium batteries degrade over time even if you do not cycle them. The life of the commonly used chemistries is only around 3 years.

r00fus 2y ago
Explain my 7.5 year old EV with 95% battery health and 65k miles driven? Your 2nd sentence has issues with reality.
- DylanDmitri 2y ago
  Some EVs start with capacity “gated off” to limit the depth of early cycles and provide a more graceful degradation.
  - r00fus 2y ago
    But a lifetime of 3y doesn't jive with why my 7 year old vehicle is mostly fully functional. Even with 10% over-provisioning (amazingly expensive 7y ago), that's only a 15% reduction in 7 years. The statement "The life of the commonly used chemistries is only around 3 years" is completely misleading and probably inaccurate.
    - freedomben 2y ago
      I don't know about the 3 years number, but generally speaking battery lives are estimates/averages based on statistics. If you have a battery that was well cared for it will outperform the average. Also sometimes it's just dumb luck. One aberration isn't nearly enough data to throw out the entire premise
- saidinesh5 2y ago
  It depends on your usage too, along with the exact chemistry and form factor of the lithium battery. A lot of people report lithium batteries swelling up in their phones/tablets around 3-4 years of usage.
  - mapt 2y ago
    Phone batteries are lithium polymer pouch cells, the least durable type commonly used. Car cells with lithium ion NMC cylindrical cells are much better, and LIFEPO4 in turn is several times more durable than that. You would be wise to insist on an EV with LIFEPO4 batteries in the sense that calendar lifetimes are more likely to be on par with traditional engines.
- kccqzy 2y ago
  The explanation is simple. OP said commonly used chemistries. That would be something like LCO. Your EV battery is probably NMC.
  - r00fus 2y ago
    NMC is the most commonly used battery chemistry in the US for EVs which is what this thread was all about.
api 2y ago
Degrade to what extent? I have a 12 year old Nissan Leaf that's lost maybe 25% of its range. Still absolutely usable as a neighborhood car.
- fredrikholm 2y ago
  > neighborhood car Not familiar with that term, what does it mean? Shared ride? A car for walking distances?
  - globular-toast 2y ago
    An electric wheelchair.
  - BobaFloutist 2y ago
    I think they mean "city car" as opposed to "road trip car" or "rural car."
  - Cupprum 2y ago
    Going to work, groceries and so on, the regular stuff. If the city was walkable, you would not need such a thing as neighborhood car, you could just use a bike, but apparently as a society at many places we have decided that the cars are the best mode of transportation ever.
- neogodless 2y ago
  A 2013 Nissan Leaf should get 60-75 miles of range (depending on how much of thebattery you use, as well as climate, and other driving conditions). If it got ~80 miles new, it would still get 60 miles now. That might be enough for someone to make a short commute, though unless they have relatively fast charging at home, a 20+ mile commute 5 days a week might be tough to pull off. But most errands would fall well within the existing / remaining range.
  - chgs 2y ago
    50 mile round trip at 3 miles per kWh would be under 20kWh, or 1.6kW for 12 hours, about the same as a plug in heater on max, easily doable in a normal socket let alone a dedicated charge circuit.

tecleandor 2y ago

But it could be very interesting for commercial or industrial use: commercial vehicles that are constantly driven and charged, power reserve batteries, tools... And I guess that you could make devices with smaller batteries and fast charge, with less fear of wearing them early.

WaltYoder 2y ago

For grid-level solar energy, we will need batteries that cycle at least 200 times per year. A system that requires replacing batteries every 5 years can't really be described as "renewable energy".

gpm 2y ago
As long as "replace" includes "take the old batteries and turn them into raw materials for making new batteries" it definitely can. Typical issues with old batteries are things like dendrite growth. There's nothing wrong with the materials that went into making the battery, they've just reshaped themselves into an unfortunate spiky structure.

flowerthoughts 2y ago

Note that LiFePO/LFP batteries used in cars and large installations are rated for 5,000+ cycles. They really are on another level compared to Li-Co phone batteries that top out at 1,000.

nomel 2y ago

Most EV map displayed 0% to 100% to something like physical 5% to 95%, or even more extreme, to help.

magicalhippo 2y ago

There's also some research[1] suggesting that dynamic cycling extends lithium-ion battery life, compared to the fixed charge/discharge cycles typically done in a lab setting. In this study, we systematically compared dynamic discharge profiles representative of electric vehicle driving to the well-accepted constant current profiles. Surprisingly, we found that dynamic discharge enhances lifetime substantially compared with constant current discharge. Specifically, for the same average current and voltage window, varying the dynamic discharge profile led to an increase of up to 38% in equivalent full cycles at end of life. [1]: https://www.nature.com/articles/s41560-024-01675-8 https://www.nature.com/articles/s41560-024-01675-8

kylehotchkiss 2y ago

We even lived to see lithium ion batteries redefine what battery powered devices can even do! I remember my parents first Dell laptop with a whopping 2 hour battery life, if you weren’t doing anything processor intensive, otherwise it was basically a UPS.