{
  "node": {
    "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": []
    }
  },
  "edges": [
    {
      "id": "edge:1695",
      "source": "term:fuse",
      "target": "topic:topic-hvsafety",
      "type": "belongsTo",
      "properties": {
        "sourceFile": "terms.json"
      }
    },
    {
      "id": "edge:1696",
      "source": "term:fuse",
      "target": "term:external-short-circuit",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:1697",
      "source": "term:fuse",
      "target": "term:pyrofuse",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:1698",
      "source": "term:fuse",
      "target": "term:battery-disconnect-unit",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:1699",
      "source": "term:fuse",
      "target": "term:series-parallel",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:1700",
      "source": "term:fuse",
      "target": "term:cell-level-fuse",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    }
  ],
  "neighbors": [
    {
      "id": "topic:topic-hvsafety",
      "type": "Topic",
      "label": "High-voltage and functional safety",
      "properties": {
        "id": "topic-hvsafety",
        "name": "High-voltage and functional safety",
        "lede": "Keeping people safe from the pack’s voltage and keeping its electronics safe when they fail: insulation, switching, fusing and the functional-safety process.",
        "context": "Relate protection to faults, detection and response.",
        "example": "Normal-operation current limits do not demonstrate correct contactor behavior under a welded-contact or sensor fault.",
        "lesson_url": "https://lemonergy.com/learn/fundamentals/battery-basics/",
        "lesson_label": "Open battery basics"
      }
    },
    {
      "id": "term:external-short-circuit",
      "type": "Term",
      "label": "External short circuit",
      "properties": {
        "id": "external-short-circuit",
        "name": "External short circuit",
        "section": "topic-safety",
        "definition": "A low-resistance connection between the terminals outside the cell, driving currents of hundreds of amperes. Fuses, the current interrupt device and a positive-temperature-coefficient element are the layers of protection against it.",
        "related": [
          "internal-short-circuit",
          "fuse",
          "current-interrupt-device",
          "ptc",
          "short-circuit-test"
        ],
        "url": "https://lemonergy.com/learn/glossary/external-short-circuit/",
        "mentions": []
      }
    },
    {
      "id": "term:pyrofuse",
      "type": "Term",
      "label": "Pyrofuse",
      "properties": {
        "id": "pyrofuse",
        "name": "Pyrofuse",
        "aka": [
          "pyrotechnic disconnect"
        ],
        "section": "topic-hvsafety",
        "definition": "A high-voltage disconnect fired by a small pyrotechnic charge on command, typically from the airbag controller in a crash. It cuts the pack from the vehicle in milliseconds, faster and more reliably than a contactor can open under fault current.",
        "related": [
          "fuse",
          "contactor",
          "battery-disconnect-unit",
          "high-voltage-interlock"
        ],
        "url": "https://lemonergy.com/learn/glossary/pyrofuse/",
        "mentions": []
      }
    },
    {
      "id": "term:battery-disconnect-unit",
      "type": "Term",
      "label": "Battery disconnect unit",
      "properties": {
        "id": "battery-disconnect-unit",
        "name": "Battery disconnect unit",
        "abbr": "BDU",
        "aka": [
          "battery junction box"
        ],
        "section": "topic-hvsafety",
        "definition": "The box inside the pack that holds the contactors, pre-charge circuit, main fuse or pyrofuse and current sensor, where the pack’s high-voltage connections are made and broken.",
        "related": [
          "contactor",
          "pre-charge",
          "fuse",
          "pyrofuse",
          "current-sensor"
        ],
        "url": "https://lemonergy.com/learn/glossary/battery-disconnect-unit/",
        "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: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"
        ]
      }
    }
  ]
}