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Another option is to simply repurpose old batteries to stationary storage applications. Even if it’s only holding a five percent charge, who cares if they’re ju

Another option is to simply repurpose old batteries to stationary storage applications. Even if it’s only holding a five percent charge, who cares if they’re just sitting in a building somewhere.

snowwindwaves 8y ago
Because they take up space and space in a building isn't free. Nor is the equipment to use the batteries as storage
- JoeAltmaier 8y ago
  Nor is the electricity lost due to heating the inefficient battery. Old batteries also get hot, as their cathode(?) breaks down
  - hwillis 8y ago
    This is incorrect; the cathode only breaks down during a fire or something catostrauphic. Li ion develops higher internal resistance due to SEI buildup, which is less plastic and causes voltage sag as ions migrate. However this effect is cubic (iirc, cant look it up on the throne) so at low draw its heavily reduced. What is low draw depends very heavily on the chemistry, but at <1 C most batteries are only a couple percent less efficient. Every other energy storage method including hydraulic is far less efficient.
hwillis 8y ago
Yep! Old batteries tend to still hold a charge quite well- they become less efficient under the same load, which gives the impression that they lose capacity much faster than is actually the case. If you derate them they perform quite well- a battery may last 60% as long as it did originally, but when used more slowly it will hold more like 80% of its original capacity. In fact, battery degradation has in some cases been slower than battery innovation! Batteries have gotten better so quickly that the newer ones may have 50% more capacity even if the old ones didnt degrade much at all. Edit: its also complicated by the multitude of batteries and chemistries. Li ion is incredibly diverse compared to other battery families, and the various types can't be used together. Practically speaking you can only reuse batteries of a single chemistry and form factor, and the chemistry changes every few years or less. Its just not a stable enough industry for that yet.
WorldMaker 8y ago
Arguably that's a reason for Tesla's PowerWall project, to secondary use old car batteries as additional source for PowerWall. Interestingly, Nissan has a PowerWall-like project of their own, but only for secondary use batteries (as they want to prioritize car production, being you know a car company). You don't hear it advertised because Nissan has seen a far slower trickle of secondary use batteries than they originally expected to see, and thus have had very few of their PowerWall-like systems to sell to any market.

Another option is to simply repurpose old batteries to stationary storage applications. Even if it’s only holding a five percent charge, who cares if they’re just sitting in a building somewhere.

snowwindwaves 8y ago

Because they take up space and space in a building isn't free. Nor is the equipment to use the batteries as storage

JoeAltmaier 8y ago
Nor is the electricity lost due to heating the inefficient battery. Old batteries also get hot, as their cathode(?) breaks down
- hwillis 8y ago
  This is incorrect; the cathode only breaks down during a fire or something catostrauphic. Li ion develops higher internal resistance due to SEI buildup, which is less plastic and causes voltage sag as ions migrate. However this effect is cubic (iirc, cant look it up on the throne) so at low draw its heavily reduced. What is low draw depends very heavily on the chemistry, but at <1 C most batteries are only a couple percent less efficient. Every other energy storage method including hydraulic is far less efficient.

hwillis 8y ago

Yep! Old batteries tend to still hold a charge quite well- they become less efficient under the same load, which gives the impression that they lose capacity much faster than is actually the case. If you derate them they perform quite well- a battery may last 60% as long as it did originally, but when used more slowly it will hold more like 80% of its original capacity. In fact, battery degradation has in some cases been slower than battery innovation! Batteries have gotten better so quickly that the newer ones may have 50% more capacity even if the old ones didnt degrade much at all. Edit: its also complicated by the multitude of batteries and chemistries. Li ion is incredibly diverse compared to other battery families, and the various types can't be used together. Practically speaking you can only reuse batteries of a single chemistry and form factor, and the chemistry changes every few years or less. Its just not a stable enough industry for that yet.

WorldMaker 8y ago

Arguably that's a reason for Tesla's PowerWall project, to secondary use old car batteries as additional source for PowerWall. Interestingly, Nissan has a PowerWall-like project of their own, but only for secondary use batteries (as they want to prioritize car production, being you know a car company). You don't hear it advertised because Nissan has seen a far slower trickle of secondary use batteries than they originally expected to see, and thus have had very few of their PowerWall-like systems to sell to any market.