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What about second-life use though for lithium batteries in grid storage? We're building a lot of EVs right now. Pretty much any battery has hard to process mat

What about second-life use though for lithium batteries in grid storage? We're building a lot of EVs right now. Pretty much any battery has hard to process material in it. Packs for vehicles last between 5-15 years, but there's still a lot of energy storage capacity left. You reduce the amount of processing & mining needed AND make EVs more affordable if you can extend the life of the battery pack beyond just it's automotive application by giving it another life in grid storage.

VBprogrammer 2y ago
I can't see how this works at scale personally. You'd at minimum need standards in cell construction so that you can plug them into some kind of rack. Battery packs as standard come in too many different formats, voltages and cell chemistries etc.
- trainsarebetter 2y ago
  Not really. Most pack are 96s Chemistry wise the only real major difference for charge profiles is lfp vs standard li-ion. Pretty much every pack spits cell data out over can, and contains hv contactors. Projects like https://github.com/dalathegreat/Battery-Emulator https://github.com/dalathegreat/Battery-Emulator Standardize different pack coms for HV solar inverters. The big hurdle here is insurance. It’s a regulatory nightmare, nobody wants to spend the money to provide the data that these packs are safe for grid tie. Even though they have the data for vehicle safety…
  - VBprogrammer 2y ago
    Taking the Hyundai Ionic 5 as an example you have 3 capacities 58.2kwh, 72.6kwh and 77.4kwh with 114s2p, 180s2p, 192s2p. These have nominal voltages of 523v, 653v and 697v respectively. Even for the same car it's not trivial to use these all in the same system. It might even make most sense to couple them on the AC side but that would mean a lot of small expensive inverters.
    - pjc50 2y ago
      I'd assume the plan is not "use pack as is" but to split it into constituent 18650 cells and build a mega-pack. I'm not sure how reliable that would be..
      - VBprogrammer 2y ago
        Yeah, even that is tricky. Every different manufacturer has different packaging for the cells. The Nissan Leaf for example uses a pouch style cell rather than 18650 cells. Even if you stick to say Tesla batteries you have to undo the wire bonding and probably spot weld each battery back together, then balance and charge the pack ensuring you don't have any duff cells. It's a lot of work for reclaiming batteries on an industrial scale.
    - trainsarebetter 2y ago
      Hmm do you have any reference material stating they are in fact different series groups? that’s a odd way to do it, generally you just add more cells in each parallel group Regardless most hv solar inverters are 600v or 800v so all those packs would work fine
Tagbert 2y ago
There just aren't many car batteries that are at the end of their life in a vehicle. Their lifetime seems to be a lot longer than many thought early on. Other than the Leaf batteries, most EV batteries from 10 years ago are still going. Even with those the volume was low. Now that volume is increasing, it will still take 10-15 years before you start to see the current batteries available for reuse. The average age of a car on the road is around 12 years so you will start to see vehicles decommissioned and many of those will still have useful batteries but we need much larger numbers of batteries and sooner for grid-scale usage.
- practicemaths 2y ago
  There's growing commercial use of EVs. These will be driven harder and longer. They will not last 10+ years. The point that you're missing is that you can extend a packs life with a secondary application. That secondary application can make the cost of its first use lower making EVs more easier to adopt. This requires more and more material. However we can recycle this material back through tearing it apart, which is a costly process. It would be better to recycle a pack to its base material later than sooner. So the second life use allows for delaying the teardown & reclaiming process.
h0l0cube 2y ago
> What about second-life use though for lithium batteries in grid storage? Scale and immediacy. We already have some places in the world that have an overcapacity of renewables, but still suffer from outages due to the energy market. And if the current exponential trend continues, we will reach renewables overcapacity world wide by the mid 2030s. We essentially needed wide deployment of grid-scale batteries yesterday to offset decommissioned baseload and curtail the use of peakers that can charge through the nose when power drops. There's a strong market for a dirt cheap, dispatchable, deep cycling, and scalable battery chemistry, esp. without the resource bottleneck of lithium supply. Sodium ion wins on all those counts even though it's still, relatively speaking, a nascent technology.

VBprogrammer 2y ago

I can't see how this works at scale personally. You'd at minimum need standards in cell construction so that you can plug them into some kind of rack. Battery packs as standard come in too many different formats, voltages and cell chemistries etc.

trainsarebetter 2y ago
Not really. Most pack are 96s Chemistry wise the only real major difference for charge profiles is lfp vs standard li-ion. Pretty much every pack spits cell data out over can, and contains hv contactors. Projects like https://github.com/dalathegreat/Battery-Emulator https://github.com/dalathegreat/Battery-Emulator Standardize different pack coms for HV solar inverters. The big hurdle here is insurance. It’s a regulatory nightmare, nobody wants to spend the money to provide the data that these packs are safe for grid tie. Even though they have the data for vehicle safety…
- VBprogrammer 2y ago
  Taking the Hyundai Ionic 5 as an example you have 3 capacities 58.2kwh, 72.6kwh and 77.4kwh with 114s2p, 180s2p, 192s2p. These have nominal voltages of 523v, 653v and 697v respectively. Even for the same car it's not trivial to use these all in the same system. It might even make most sense to couple them on the AC side but that would mean a lot of small expensive inverters.
  - pjc50 2y ago
    I'd assume the plan is not "use pack as is" but to split it into constituent 18650 cells and build a mega-pack. I'm not sure how reliable that would be..
    - VBprogrammer 2y ago
      Yeah, even that is tricky. Every different manufacturer has different packaging for the cells. The Nissan Leaf for example uses a pouch style cell rather than 18650 cells. Even if you stick to say Tesla batteries you have to undo the wire bonding and probably spot weld each battery back together, then balance and charge the pack ensuring you don't have any duff cells. It's a lot of work for reclaiming batteries on an industrial scale.
  - trainsarebetter 2y ago
    Hmm do you have any reference material stating they are in fact different series groups? that’s a odd way to do it, generally you just add more cells in each parallel group Regardless most hv solar inverters are 600v or 800v so all those packs would work fine

Tagbert 2y ago

There just aren't many car batteries that are at the end of their life in a vehicle. Their lifetime seems to be a lot longer than many thought early on. Other than the Leaf batteries, most EV batteries from 10 years ago are still going. Even with those the volume was low. Now that volume is increasing, it will still take 10-15 years before you start to see the current batteries available for reuse. The average age of a car on the road is around 12 years so you will start to see vehicles decommissioned and many of those will still have useful batteries but we need much larger numbers of batteries and sooner for grid-scale usage.

practicemaths 2y ago
There's growing commercial use of EVs. These will be driven harder and longer. They will not last 10+ years. The point that you're missing is that you can extend a packs life with a secondary application. That secondary application can make the cost of its first use lower making EVs more easier to adopt. This requires more and more material. However we can recycle this material back through tearing it apart, which is a costly process. It would be better to recycle a pack to its base material later than sooner. So the second life use allows for delaying the teardown & reclaiming process.

h0l0cube 2y ago

> What about second-life use though for lithium batteries in grid storage? Scale and immediacy. We already have some places in the world that have an overcapacity of renewables, but still suffer from outages due to the energy market. And if the current exponential trend continues, we will reach renewables overcapacity world wide by the mid 2030s. We essentially needed wide deployment of grid-scale batteries yesterday to offset decommissioned baseload and curtail the use of peakers that can charge through the nose when power drops. There's a strong market for a dirt cheap, dispatchable, deep cycling, and scalable battery chemistry, esp. without the resource bottleneck of lithium supply. Sodium ion wins on all those counts even though it's still, relatively speaking, a nascent technology.