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Out of the existing tech, no. But within a couple of years the Model S will probably transition to the new 2170 cell [0]. I belive production has already starte

by dkbrk 10y ago

Out of the existing tech, no. But within a couple of years the Model S will probably transition to the new 2170 cell [0]. I belive production has already started at the Gigafactory, though the Model 3 will probably have priority. It may require some dimensional changes to the Model S though, as the cells are longer. So it may not be compatible with the existing versions of the Model S. [0]: https://electrek.co/2016/11/02/tesla-panasonic-2170-battery-cell-highest-energy-density-cell-world-cheapest-elon-musk/ https://electrek.co/2016/11/02/tesla-panasonic-2170-battery-...

StavrosK 10y ago
Apparently the new ones are worse, according to this comment? https://news.ycombinator.com/item?id=13481067 https://news.ycombinator.com/item?id=13481067
- DiabloD3 10y ago
  That comment, I think, is going to have to do side by side comparisons of the relevant figures from the manufacturer specification sheets. Not only that, there are different grades. A 18650 is a size and voltage specification. As in, it's like calling a battery a AA or AAA: any AA or AAA fits into a device and makes it run, but some AAs and AAAs last a lot longer than other batteries in flat out runtime, or survive usage in abusive devices, or in extreme weather conditions, or so forth. There are low grade 18650s just as there are high grade 18650s. Maximum capacity isn't the only way to measure a battery, but also it's maximum discharge rate and thermal characteristics under load; as in, larger capacity isn't always better in some use cases. It sounds like he saw one specification sheet of the new upcoming product, and generalized it to every battery in that size. A quick Google Search (tm) did not yield any useful statements on such. I personally assume that the grade of battery used in the Model 3 battery packs is going to be similar to the lowest grade used in the Model S, but with lower available engine torque to compensate for the smaller overall battery pack size.
  - owenversteeg 10y ago
    Hey, so I wrote that comment :) > A 18650 is a size and voltage specification. As in, it's like calling a battery a AA or AAA: any AA or AAA fits into a device and makes it run, but some AAs and AAAs last a lot longer than other batteries in flat out runtime, or survive usage in abusive devices, or in extreme weather conditions, or so forth. 18650 doesn't mean anything other than a cylinder 18mm diameter by 65mm long; it doesn't imply a certain voltage or anything else. I've worked with 18650s that have voltages from 2V to 4.4V. Nonrechargeable 18650s, though quite rare, exist at even lower or higher voltages. I've got access to several spec sheets from Panasonic, who Tesla is pairing with, in combination with public spec sheets from existing 21700 cells. My guesses at Tesla's final 21700 battery specs are a combination of these spec sheets, my own knowledge about batteries, and some physical limitations (e.x. the theoretical max power density shrinks as the cell grows, and 21700s are roughly 50% more volume than 18650s.) > There are low grade 18650s just as there are high grade 18650s. Maximum capacity isn't the only way to measure a battery, but also it's maximum discharge rate and thermal characteristics under load; as in, larger capacity isn't always better in some use cases. Yep, that's why I addressed those things in my comment. Thermal issues are particularly interesting with Tesla's packs.
    - DiabloD3 10y ago
      Thanks for the response.

by dkbrk 10y ago

StavrosK 10y ago

Apparently the new ones are worse, according to this comment? https://news.ycombinator.com/item?id=13481067 https://news.ycombinator.com/item?id=13481067

DiabloD3 10y ago
That comment, I think, is going to have to do side by side comparisons of the relevant figures from the manufacturer specification sheets. Not only that, there are different grades. A 18650 is a size and voltage specification. As in, it's like calling a battery a AA or AAA: any AA or AAA fits into a device and makes it run, but some AAs and AAAs last a lot longer than other batteries in flat out runtime, or survive usage in abusive devices, or in extreme weather conditions, or so forth. There are low grade 18650s just as there are high grade 18650s. Maximum capacity isn't the only way to measure a battery, but also it's maximum discharge rate and thermal characteristics under load; as in, larger capacity isn't always better in some use cases. It sounds like he saw one specification sheet of the new upcoming product, and generalized it to every battery in that size. A quick Google Search (tm) did not yield any useful statements on such. I personally assume that the grade of battery used in the Model 3 battery packs is going to be similar to the lowest grade used in the Model S, but with lower available engine torque to compensate for the smaller overall battery pack size.
- owenversteeg 10y ago
  Hey, so I wrote that comment :) > A 18650 is a size and voltage specification. As in, it's like calling a battery a AA or AAA: any AA or AAA fits into a device and makes it run, but some AAs and AAAs last a lot longer than other batteries in flat out runtime, or survive usage in abusive devices, or in extreme weather conditions, or so forth. 18650 doesn't mean anything other than a cylinder 18mm diameter by 65mm long; it doesn't imply a certain voltage or anything else. I've worked with 18650s that have voltages from 2V to 4.4V. Nonrechargeable 18650s, though quite rare, exist at even lower or higher voltages. I've got access to several spec sheets from Panasonic, who Tesla is pairing with, in combination with public spec sheets from existing 21700 cells. My guesses at Tesla's final 21700 battery specs are a combination of these spec sheets, my own knowledge about batteries, and some physical limitations (e.x. the theoretical max power density shrinks as the cell grows, and 21700s are roughly 50% more volume than 18650s.) > There are low grade 18650s just as there are high grade 18650s. Maximum capacity isn't the only way to measure a battery, but also it's maximum discharge rate and thermal characteristics under load; as in, larger capacity isn't always better in some use cases. Yep, that's why I addressed those things in my comment. Thermal issues are particularly interesting with Tesla's packs.
  - DiabloD3 10y ago
    Thanks for the response.