{
  "node": {
    "id": "term:cell-level-fuse",
    "type": "Term",
    "label": "Cell-level fuse",
    "properties": {
      "id": "cell-level-fuse",
      "name": "Cell-level fuse",
      "aka": [
        "tab fuse",
        "cell fuse"
      ],
      "section": "topic-safety",
      "definition": "A fuse protecting one cell rather than the pack: a necked section of the internal current collector in many automotive prismatic cells, or a thin wire bond joining each cylindrical cell to the busbar. It isolates a single shorted cell from its parallel neighbours; in some prismatic cells a pressure-driven membrane deliberately shorts the terminals on overcharge to blow it.",
      "related": [
        "fuse",
        "wire-bonding",
        "series-parallel",
        "internal-short-circuit",
        "current-interrupt-device",
        "prismatic-cell"
      ],
      "url": "https://lemonergy.com/learn/glossary/cell-level-fuse/",
      "mentions": [
        "current-collector",
        "cylindrical-cell",
        "overcharge",
        "busbar"
      ]
    }
  },
  "edges": [
    {
      "id": "edge:6614",
      "source": "term:cell-level-fuse",
      "target": "topic:topic-safety",
      "type": "belongsTo",
      "properties": {
        "sourceFile": "terms.json"
      }
    },
    {
      "id": "edge:6615",
      "source": "term:cell-level-fuse",
      "target": "term:fuse",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:6616",
      "source": "term:cell-level-fuse",
      "target": "term:wire-bonding",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:6617",
      "source": "term:cell-level-fuse",
      "target": "term:series-parallel",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:6618",
      "source": "term:cell-level-fuse",
      "target": "term:internal-short-circuit",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:6619",
      "source": "term:cell-level-fuse",
      "target": "term:current-interrupt-device",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:6620",
      "source": "term:cell-level-fuse",
      "target": "term:prismatic-cell",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:mentions/cell-level-fuse/current-collector",
      "source": "term:cell-level-fuse",
      "target": "term:current-collector",
      "type": "mentions",
      "properties": {
        "sourceFile": "terms.json",
        "method": "build_glossary.mention_index + mentions",
        "field": "definition",
        "meaning": "Text mention; not a causal claim"
      }
    },
    {
      "id": "edge:mentions/cell-level-fuse/cylindrical-cell",
      "source": "term:cell-level-fuse",
      "target": "term:cylindrical-cell",
      "type": "mentions",
      "properties": {
        "sourceFile": "terms.json",
        "method": "build_glossary.mention_index + mentions",
        "field": "definition",
        "meaning": "Text mention; not a causal claim"
      }
    },
    {
      "id": "edge:mentions/cell-level-fuse/overcharge",
      "source": "term:cell-level-fuse",
      "target": "term:overcharge",
      "type": "mentions",
      "properties": {
        "sourceFile": "terms.json",
        "method": "build_glossary.mention_index + mentions",
        "field": "definition",
        "meaning": "Text mention; not a causal claim"
      }
    },
    {
      "id": "edge:mentions/cell-level-fuse/busbar",
      "source": "term:cell-level-fuse",
      "target": "term:busbar",
      "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-safety",
      "type": "Topic",
      "label": "Safety and abuse",
      "properties": {
        "id": "topic-safety",
        "name": "Safety and abuse",
        "lede": "How cells fail dangerously, how that is tested, and what is built in to stop it.",
        "context": "Connect mechanisms with appropriate test evidence.",
        "example": "A low normal-load temperature does not demonstrate thermal-runaway containment.",
        "lesson_url": "https://lemonergy.com/learn/fundamentals/battery-aging/",
        "lesson_label": "Open degradation mechanisms"
      }
    },
    {
      "id": "term:fuse",
      "type": "Term",
      "label": "Fuse",
      "properties": {
        "id": "fuse",
        "name": "Fuse",
        "section": "topic-hvsafety",
        "definition": "A link that melts and opens the circuit when current exceeds its rating. Packs use a main fuse in the high-voltage path and often a small fuse on each parallel cell connection, so one shorted cell does not drain its neighbours into the fault.",
        "related": [
          "external-short-circuit",
          "pyrofuse",
          "battery-disconnect-unit",
          "series-parallel",
          "cell-level-fuse"
        ],
        "url": "https://lemonergy.com/learn/glossary/fuse/",
        "mentions": []
      }
    },
    {
      "id": "term:wire-bonding",
      "type": "Term",
      "label": "Wire bonding",
      "properties": {
        "id": "wire-bonding",
        "name": "Wire bonding",
        "aka": [
          "wire bond",
          "fusible link"
        ],
        "section": "topic-manufacturing",
        "definition": "Connecting each cell terminal to a busbar or collector plate with a thin aluminium wire, often a few hundred micrometres thick, attached ultrasonically at both ends. The wire can be sized to act as a fuse, so a cell that shorts internally is cut off from its parallel neighbours; Tesla’s cylindrical-cell packs are the best-known example.",
        "related": [
          "ultrasonic-welding",
          "busbar",
          "fuse",
          "cylindrical-cell",
          "series-parallel"
        ],
        "url": "https://lemonergy.com/learn/glossary/wire-bonding/",
        "mentions": []
      }
    },
    {
      "id": "term:series-parallel",
      "type": "Term",
      "label": "Series and parallel connection",
      "properties": {
        "id": "series-parallel",
        "name": "Series and parallel connection",
        "aka": [
          "xSyP"
        ],
        "section": "topic-pack",
        "definition": "Cells in series add their voltages; cells in parallel add their capacities and share current. A pack is described as, for example, 96s4p: 96 groups in series, each of 4 cells in parallel. Series strings need balancing; parallel groups self-balance through their shared terminals.",
        "formula": "V = n_s·V_cell, Q = n_p·Q_cell",
        "related": [
          "module",
          "cell-balancing",
          "pack-voltage",
          "volt",
          "fuse"
        ],
        "lesson": "fundamentals/battery-basics/#cell-module-pack",
        "example": {
          "title": "Assemble an ideal 4s2p pack",
          "text": "Eight identical 3.6 V, 5 Ah cells arranged as four series groups with two cells in parallel give 14.4 V nominal, 10 Ah and 144 Wh. Interconnect losses, cell variation and usable voltage limits are additional constraints."
        },
        "url": "https://lemonergy.com/learn/glossary/series-parallel/",
        "mentions": []
      }
    },
    {
      "id": "term:internal-short-circuit",
      "type": "Term",
      "label": "Internal short circuit",
      "properties": {
        "id": "internal-short-circuit",
        "name": "Internal short circuit",
        "abbr": "ISC",
        "section": "topic-safety",
        "definition": "An unintended electronic path between the electrodes inside a cell — through a metal particle, a burr, a damaged separator or lithium deposits. It discharges the cell internally and turns its energy into local heat.",
        "related": [
          "thermal-runaway",
          "dendrite",
          "separator",
          "external-short-circuit",
          "self-discharge",
          "internal-short-trigger-device"
        ],
        "lesson": "fundamentals/cell-anatomy/#short-circuit",
        "url": "https://lemonergy.com/learn/glossary/internal-short-circuit/",
        "mentions": [
          "electronic-path",
          "burr",
          "metal-particle-contamination"
        ]
      }
    },
    {
      "id": "term:current-interrupt-device",
      "type": "Term",
      "label": "Current interrupt device",
      "properties": {
        "id": "current-interrupt-device",
        "name": "Current interrupt device",
        "abbr": "CID",
        "section": "topic-safety",
        "definition": "A pressure-activated switch in the cap of a cylindrical cell. When internal pressure rises, usually from overcharge, a disc flips and permanently breaks the current path, removing the cell from the circuit before it vents.",
        "related": [
          "vent",
          "overcharge",
          "ptc",
          "cylindrical-cell"
        ],
        "url": "https://lemonergy.com/learn/glossary/current-interrupt-device/",
        "mentions": []
      }
    },
    {
      "id": "term:prismatic-cell",
      "type": "Term",
      "label": "Prismatic cell",
      "properties": {
        "id": "prismatic-cell",
        "name": "Prismatic cell",
        "section": "topic-chemistries",
        "definition": "A cell in a rigid rectangular metal case, holding either a flattened jelly roll or stacked sheets. Large prismatic cells pack tightly into battery packs.",
        "related": [
          "can",
          "jelly-roll",
          "stacking",
          "cylindrical-cell",
          "pouch-cell"
        ],
        "lesson": "fundamentals/cell-production/#formats",
        "example": {
          "title": "Geometry is one constraint",
          "text": "Two rectangular cells can fit similar spaces but use different terminals and electrical ratings."
        },
        "url": "https://lemonergy.com/learn/glossary/prismatic-cell/",
        "mentions": []
      }
    },
    {
      "id": "term:current-collector",
      "type": "Term",
      "label": "Current collector",
      "properties": {
        "id": "current-collector",
        "name": "Current collector",
        "section": "topic-components",
        "definition": "The thin metal foil that carries electrons between an electrode and the external circuit — usually copper on the negative side and aluminium on the positive side.",
        "related": [
          "copper-foil",
          "aluminium-foil",
          "tab",
          "electronic-path"
        ],
        "lesson": "fundamentals/cell-anatomy/#components",
        "example": {
          "title": "Follow current to a tab",
          "text": "Current converges through foil toward the tab. The collector contributes mass and resistance without being the principal active material."
        },
        "url": "https://lemonergy.com/learn/glossary/current-collector/",
        "mentions": [
          "electrode"
        ]
      }
    },
    {
      "id": "term:cylindrical-cell",
      "type": "Term",
      "label": "Cylindrical cell",
      "properties": {
        "id": "cylindrical-cell",
        "name": "Cylindrical cell",
        "aka": [
          "18650",
          "21700",
          "4680"
        ],
        "section": "topic-chemistries",
        "definition": "A cell made by winding the electrodes into a jelly roll and sealing it in a round metal can. Sizes are named by their dimensions: a 21700 cell is 21 mm across and 70 mm long.",
        "related": [
          "jelly-roll",
          "can",
          "tabless-design",
          "prismatic-cell",
          "pouch-cell",
          "centre-pin"
        ],
        "lesson": "fundamentals/cell-production/#formats",
        "example": {
          "title": "Shape versus ratings",
          "text": "A cylindrical shape does not supply the model’s capacity, resistance or voltage limits; those belong to the actual cell."
        },
        "url": "https://lemonergy.com/learn/glossary/cylindrical-cell/",
        "mentions": [
          "winding"
        ]
      }
    },
    {
      "id": "term:overcharge",
      "type": "Term",
      "label": "Overcharge",
      "properties": {
        "id": "overcharge",
        "name": "Overcharge",
        "section": "topic-charging",
        "definition": "Charging past the upper cutoff voltage. The positive electrode over-delithiates and releases oxygen, the electrolyte oxidises and lithium plates on the negative, so an unprotected overcharge can end in thermal runaway.",
        "related": [
          "cutoff-voltage",
          "thermal-runaway",
          "bms",
          "overcharge-test",
          "electrolyte-decomposition"
        ],
        "url": "https://lemonergy.com/learn/glossary/overcharge/",
        "mentions": [
          "electrode",
          "positive-electrode",
          "electrolyte"
        ]
      }
    },
    {
      "id": "term:busbar",
      "type": "Term",
      "label": "Busbar",
      "properties": {
        "id": "busbar",
        "name": "Busbar",
        "section": "topic-pack",
        "definition": "A rigid copper or aluminium conductor that joins cell terminals into series and parallel groups, and modules into the pack. Its cross-section is sized for current and heating, and its joints — welded or bolted — are a classic source of resistance and failure.",
        "related": [
          "series-parallel",
          "terminal",
          "laser-welding",
          "internal-resistance",
          "wire-bonding"
        ],
        "url": "https://lemonergy.com/learn/glossary/busbar/",
        "mentions": []
      }
    }
  ]
}