{
  "node": {
    "id": "term:ab-battery-system",
    "type": "Term",
    "label": "AB battery system",
    "properties": {
      "id": "ab-battery-system",
      "name": "AB battery system",
      "aka": [
        "AB battery pack",
        "mixed-chemistry pack"
      ],
      "section": "topic-pack",
      "definition": "A pack that integrates two cell chemistries under one BMS — sodium-ion with lithium-ion, say, or LFP with NMC — so that one type covers the other’s weakness, such as poor cold-weather power or low energy density. CATL used the name at its 2021 sodium-ion launch; the BMS must model both voltage curves to estimate SOC.",
      "related": [
        "sodium-ion",
        "lfp",
        "nmc",
        "bms",
        "ocv-soc-curve",
        "pack"
      ],
      "url": "https://lemonergy.com/learn/glossary/ab-battery-system/",
      "mentions": [
        "energy-density",
        "state-of-charge"
      ]
    }
  },
  "edges": [
    {
      "id": "edge:4922",
      "source": "term:ab-battery-system",
      "target": "topic:topic-pack",
      "type": "belongsTo",
      "properties": {
        "sourceFile": "terms.json"
      }
    },
    {
      "id": "edge:4923",
      "source": "term:ab-battery-system",
      "target": "term:sodium-ion",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:4924",
      "source": "term:ab-battery-system",
      "target": "term:lfp",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:4925",
      "source": "term:ab-battery-system",
      "target": "term:nmc",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:4926",
      "source": "term:ab-battery-system",
      "target": "term:bms",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:4927",
      "source": "term:ab-battery-system",
      "target": "term:ocv-soc-curve",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:4928",
      "source": "term:ab-battery-system",
      "target": "term:pack",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:mentions/ab-battery-system/energy-density",
      "source": "term:ab-battery-system",
      "target": "term:energy-density",
      "type": "mentions",
      "properties": {
        "sourceFile": "terms.json",
        "method": "build_glossary.mention_index + mentions",
        "field": "definition",
        "meaning": "Text mention; not a causal claim"
      }
    },
    {
      "id": "edge:mentions/ab-battery-system/state-of-charge",
      "source": "term:ab-battery-system",
      "target": "term:state-of-charge",
      "type": "mentions",
      "properties": {
        "sourceFile": "terms.json",
        "method": "build_glossary.mention_index + mentions",
        "field": "definition",
        "meaning": "Text mention; not a causal claim"
      }
    }
  ],
  "neighbors": [
    {
      "id": "topic:topic-pack",
      "type": "Topic",
      "label": "Modules, packs and battery management",
      "properties": {
        "id": "topic-pack",
        "name": "Modules, packs and battery management",
        "lede": "From a single cell to a working battery system, and the electronics that keep it safe.",
        "context": "Make series/parallel architecture explicit.",
        "example": "Twelve 3.6 V, 5 Ah cells in 6s2p give 21.6 V, 10 Ah and 216 Wh nominally before other restrictions.",
        "lesson_url": "https://lemonergy.com/learn/fundamentals/cell-architecture/",
        "lesson_label": "Open cell architecture"
      }
    },
    {
      "id": "term:sodium-ion",
      "type": "Term",
      "label": "Sodium-ion battery",
      "properties": {
        "id": "sodium-ion",
        "name": "Sodium-ion battery",
        "abbr": "Na-ion",
        "section": "topic-other-chemistries",
        "definition": "A cell built like a lithium-ion cell but shuttling sodium ions, usually between a hard-carbon negative electrode and a layered oxide or Prussian-blue positive. It uses no lithium, cobalt or copper, at the cost of lower energy density.",
        "related": [
          "hard-carbon",
          "lithium-ion",
          "energy-density",
          "stationary-storage",
          "seawater-battery"
        ],
        "url": "https://lemonergy.com/learn/glossary/sodium-ion/",
        "mentions": [
          "electrode",
          "negative-electrode",
          "cobalt",
          "layered-oxide"
        ]
      }
    },
    {
      "id": "term:lfp",
      "type": "Term",
      "label": "LFP",
      "properties": {
        "id": "lfp",
        "name": "LFP",
        "aka": [
          "lithium iron phosphate",
          "LiFePO₄"
        ],
        "section": "topic-chemistries",
        "definition": "A positive electrode material, LiFePO₄, giving cells a nominal voltage around 3.2 V, long cycle life and good thermal stability, but less energy per kilogram than nickel-rich oxides. Its flat voltage curve makes state of charge hard to read from voltage alone.",
        "related": [
          "cathode-active-material",
          "nmc",
          "lmfp",
          "ocv-soc-curve",
          "cycle-life"
        ],
        "lesson": "fundamentals/cell-anatomy/#voltage",
        "example": {
          "title": "Chemistry is not the whole datasheet",
          "text": "Two LFP products can differ in format, loading, capacity and current limits. Their cathode family alone does not make them interchangeable."
        },
        "url": "https://lemonergy.com/learn/glossary/lfp/",
        "mentions": [
          "electrode",
          "positive-electrode",
          "nominal-voltage",
          "discharge-curve",
          "state-of-charge"
        ]
      }
    },
    {
      "id": "term:nmc",
      "type": "Term",
      "label": "NMC",
      "properties": {
        "id": "nmc",
        "name": "NMC",
        "aka": [
          "NCM",
          "nickel manganese cobalt oxide",
          "LiNiMnCoO₂"
        ],
        "section": "topic-chemistries",
        "definition": "A family of layered-oxide positive electrode materials, LiNiₓMnᵧCo₁₋ₓ₋ᵧO₂, used in many electric-vehicle cells. Variants are named by their metal ratio: NMC811 has eight parts nickel to one each of manganese and cobalt.",
        "related": [
          "cathode-active-material",
          "high-nickel",
          "nca",
          "lfp",
          "cobalt"
        ],
        "lesson": "fundamentals/cell-anatomy/#components",
        "example": {
          "title": "Read the composition label",
          "text": "NMC811 denotes nominal nickel:manganese:cobalt proportions of 8:1:1 in the transition-metal component, not 80% nickel by whole-cell mass."
        },
        "url": "https://lemonergy.com/learn/glossary/nmc/",
        "mentions": [
          "electrode",
          "positive-electrode",
          "manganese"
        ]
      }
    },
    {
      "id": "term:bms",
      "type": "Term",
      "label": "Battery management system",
      "properties": {
        "id": "bms",
        "name": "Battery management system",
        "abbr": "BMS",
        "section": "topic-pack",
        "definition": "The electronics and software that keep a battery inside its safe window: measuring every cell voltage and many temperatures, estimating SOC and SOH, balancing cells, computing current limits, controlling the contactors and reporting over the vehicle network.",
        "related": [
          "state-of-charge",
          "cell-balancing",
          "state-of-power",
          "cell-supervision-circuit",
          "contactor",
          "can-bus"
        ],
        "lesson": "fundamentals/battery-basics/#cell-module-pack",
        "url": "https://lemonergy.com/learn/glossary/bms/",
        "mentions": [
          "state-of-health",
          "cell-voltage"
        ]
      }
    },
    {
      "id": "term:ocv-soc-curve",
      "type": "Term",
      "label": "OCV–SOC curve",
      "properties": {
        "id": "ocv-soc-curve",
        "name": "OCV–SOC curve",
        "section": "topic-state",
        "definition": "The characteristic relation between a cell’s open-circuit voltage and its state of charge, measured once at low current and stored in the BMS. A steep curve, as for NMC, makes SOC easy to read from voltage; LFP’s flat curve does not.",
        "related": [
          "open-circuit-voltage",
          "state-of-charge",
          "coulomb-counting",
          "lfp",
          "voltage-plateau",
          "ocv-test"
        ],
        "url": "https://lemonergy.com/learn/glossary/ocv-soc-curve/",
        "mentions": [
          "bms"
        ]
      }
    },
    {
      "id": "term:pack",
      "type": "Term",
      "label": "Battery pack",
      "properties": {
        "id": "pack",
        "name": "Battery pack",
        "section": "topic-pack",
        "definition": "The complete battery as installed: modules or cells, the BMS, contactors and fuses, busbars, cooling, sensors and an enclosure. Its energy is the sum of its cells’ energies; its mass and volume are a good deal more.",
        "related": [
          "module",
          "bms",
          "battery-disconnect-unit",
          "thermal-management",
          "cell-to-pack-ratio",
          "enclosure"
        ],
        "lesson": "fundamentals/battery-basics/#cell-module-pack",
        "url": "https://lemonergy.com/learn/glossary/pack/",
        "mentions": []
      }
    },
    {
      "id": "term:energy-density",
      "type": "Term",
      "label": "Energy density",
      "properties": {
        "id": "energy-density",
        "name": "Energy density",
        "aka": [
          "volumetric energy density"
        ],
        "section": "topic-ratings",
        "definition": "Stored energy per unit volume, in watt-hours per litre. It is the figure that matters when space is the constraint, as in a phone or under a car floor; high-energy cylindrical cells pass 700 Wh/L.",
        "unit": "Wh/L",
        "related": [
          "specific-energy",
          "nominal-energy",
          "ragone-plot",
          "areal-loading"
        ],
        "lesson": "fundamentals/capacity-and-c-rate/#energy",
        "url": "https://lemonergy.com/learn/glossary/energy-density/",
        "mentions": []
      }
    },
    {
      "id": "term:state-of-charge",
      "type": "Term",
      "label": "State of charge",
      "properties": {
        "id": "state-of-charge",
        "name": "State of charge",
        "abbr": "SOC",
        "section": "topic-state",
        "definition": "How full a cell is, as a fraction of its available capacity. State of charge, like temperature, affects how fast a stored cell ages.",
        "unit": "%",
        "related": [
          "depth-of-discharge",
          "ocv-soc-curve",
          "coulomb-counting",
          "state-of-health",
          "bms"
        ],
        "lesson": "fundamentals/battery-aging/#storage-soc",
        "example": {
          "title": "Interpret a charge inventory",
          "text": "If available capacity is 5 Ah and 3 Ah remains by the chosen estimator, SOC is 60%. A different estimate of available capacity changes this percentage, so compare SOC values only with the capacity convention recorded."
        },
        "url": "https://lemonergy.com/learn/glossary/state-of-charge/",
        "mentions": [
          "usable-capacity"
        ]
      }
    }
  ]
}