{
  "node": {
    "id": "term:fmvss-305a",
    "type": "Term",
    "label": "FMVSS 305a",
    "properties": {
      "id": "fmvss-305a",
      "name": "FMVSS 305a",
      "aka": [
        "FMVSS No. 305a"
      ],
      "section": "topic-standards-vehicle",
      "definition": "The US vehicle safety standard that replaces FMVSS 305 and largely adopts GTR 20. Besides protection against electric shock and electrolyte spillage, it adds requirements for the traction battery itself — overcharge, short-circuit and over-temperature protection, management of vented gases, water exposure — and extends coverage to heavy vehicles. The December 2024 final rule applies from September 2027 for light vehicles and 2028 for heavy ones.",
      "related": [
        "gtr-20",
        "un-r100",
        "rechargeable-energy-storage-system",
        "thermal-propagation",
        "electric-vehicle"
      ],
      "url": "https://lemonergy.com/learn/glossary/fmvss-305a/",
      "mentions": [
        "electrolyte",
        "overcharge",
        "vehicle-crash-test"
      ]
    }
  },
  "edges": [
    {
      "id": "edge:6216",
      "source": "term:fmvss-305a",
      "target": "topic:topic-standards-vehicle",
      "type": "belongsTo",
      "properties": {
        "sourceFile": "terms.json"
      }
    },
    {
      "id": "edge:6217",
      "source": "term:fmvss-305a",
      "target": "term:gtr-20",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:6218",
      "source": "term:fmvss-305a",
      "target": "term:un-r100",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:6219",
      "source": "term:fmvss-305a",
      "target": "term:rechargeable-energy-storage-system",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:6220",
      "source": "term:fmvss-305a",
      "target": "term:thermal-propagation",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:6221",
      "source": "term:fmvss-305a",
      "target": "term:electric-vehicle",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:mentions/fmvss-305a/electrolyte",
      "source": "term:fmvss-305a",
      "target": "term:electrolyte",
      "type": "mentions",
      "properties": {
        "sourceFile": "terms.json",
        "method": "build_glossary.mention_index + mentions",
        "field": "definition",
        "meaning": "Text mention; not a causal claim"
      }
    },
    {
      "id": "edge:mentions/fmvss-305a/overcharge",
      "source": "term:fmvss-305a",
      "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/fmvss-305a/vehicle-crash-test",
      "source": "term:fmvss-305a",
      "target": "term:vehicle-crash-test",
      "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-standards-vehicle",
      "type": "Topic",
      "label": "Vehicle and transport standards",
      "properties": {
        "id": "topic-standards-vehicle",
        "name": "Vehicle and transport standards",
        "lede": "The regulations and standards a vehicle battery must meet to be approved, and the rules for shipping batteries by road, sea and air.",
        "context": "Check issuing organization, edition, scope and market.",
        "example": "Shipping tests and vehicle battery approval tests address different uses; passing one does not automatically satisfy another.",
        "lesson_url": "https://lemonergy.com/learn/fundamentals/battery-basics/",
        "lesson_label": "Open battery basics"
      }
    },
    {
      "id": "term:gtr-20",
      "type": "Term",
      "label": "GTR 20",
      "properties": {
        "id": "gtr-20",
        "name": "GTR 20",
        "aka": [
          "UN GTR No. 20",
          "EVS-GTR"
        ],
        "section": "topic-standards-vehicle",
        "definition": "The UN Global Technical Regulation on electric vehicle safety, the basis of national rules in Europe, China, Japan and elsewhere. Its thermal propagation clause requires a warning to occupants at least five minutes before a hazardous condition in the cabin.",
        "related": [
          "propagation-test",
          "thermal-propagation",
          "iec-62660",
          "un-r100-03"
        ],
        "url": "https://lemonergy.com/learn/glossary/gtr-20/",
        "mentions": [
          "electric-vehicle"
        ]
      }
    },
    {
      "id": "term:un-r100",
      "type": "Term",
      "label": "UN Regulation No. 100",
      "properties": {
        "id": "un-r100",
        "name": "UN Regulation No. 100",
        "abbr": "R100",
        "aka": [
          "ECE R100",
          "UN ECE R100"
        ],
        "section": "topic-standards-vehicle",
        "definition": "The UNECE type-approval regulation for the electric powertrain of cars, buses and trucks, covering protection against electric shock and, in part II, the rechargeable energy storage system itself. A vehicle sold in the EU and most of the world must carry an R100 approval for its battery.",
        "related": [
          "un-r100-part-2",
          "un-r100-03",
          "gtr-20",
          "rechargeable-energy-storage-system",
          "insulation-resistance",
          "high-voltage-interlock"
        ],
        "url": "https://lemonergy.com/learn/glossary/un-r100/",
        "mentions": []
      }
    },
    {
      "id": "term:rechargeable-energy-storage-system",
      "type": "Term",
      "label": "Rechargeable energy storage system",
      "properties": {
        "id": "rechargeable-energy-storage-system",
        "name": "Rechargeable energy storage system",
        "abbr": "REESS",
        "section": "topic-standards-vehicle",
        "definition": "The regulatory name, in UN R100 and GTR 20, for the whole traction battery as installed: cells, housing, management electronics, connectors and cooling. Tests apply to the REESS as a unit, which is why a cell approval alone is not a vehicle approval.",
        "related": [
          "un-r100",
          "pack",
          "bms",
          "gtr-20"
        ],
        "url": "https://lemonergy.com/learn/glossary/rechargeable-energy-storage-system/",
        "mentions": []
      }
    },
    {
      "id": "term:thermal-propagation",
      "type": "Term",
      "label": "Thermal propagation",
      "properties": {
        "id": "thermal-propagation",
        "name": "Thermal propagation",
        "section": "topic-safety",
        "definition": "Thermal runaway spreading from one cell to its neighbours through conducted heat, hot gas and flame. Pack designs are judged by whether, and how slowly, a single failing cell takes the rest with it.",
        "related": [
          "thermal-runaway",
          "thermal-barrier",
          "venting",
          "module",
          "propagation-test"
        ],
        "url": "https://lemonergy.com/learn/glossary/thermal-propagation/",
        "mentions": []
      }
    },
    {
      "id": "term:electric-vehicle",
      "type": "Term",
      "label": "Electric vehicle",
      "properties": {
        "id": "electric-vehicle",
        "name": "Electric vehicle",
        "abbr": "EV",
        "aka": [
          "BEV",
          "battery electric vehicle"
        ],
        "section": "topic-applications",
        "definition": "A vehicle driven by an electric motor from a battery charged from the grid. A battery electric vehicle has no engine; it is the largest market for lithium-ion cells and the driver of most pack technology.",
        "related": [
          "hybrid-vehicle",
          "range",
          "pack",
          "regenerative-braking",
          "maritime-battery",
          "industrial-vehicle-battery"
        ],
        "url": "https://lemonergy.com/learn/glossary/electric-vehicle/",
        "mentions": []
      }
    },
    {
      "id": "term:electrolyte",
      "type": "Term",
      "label": "Electrolyte",
      "properties": {
        "id": "electrolyte",
        "name": "Electrolyte",
        "section": "topic-electrolytes",
        "definition": "The ion-conducting medium between the electrodes. In a liquid-electrolyte cell it fills the pores of both electrodes and the separator, so it is not a separate structural layer.",
        "related": [
          "lithium-salt",
          "carbonate-solvent",
          "electrolyte-additive",
          "ionic-conductivity",
          "solid-electrolyte",
          "ionic-liquid-electrolyte"
        ],
        "lesson": "fundamentals/cell-architecture/#electrolyte",
        "example": {
          "title": "Ions and electrons",
          "text": "Electrolyte carries ions between electrodes; the external circuit carries electrons. The two paths serve different roles."
        },
        "url": "https://lemonergy.com/learn/glossary/electrolyte/",
        "mentions": [
          "separator"
        ]
      }
    },
    {
      "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:vehicle-crash-test",
      "type": "Term",
      "label": "Vehicle crash test",
      "properties": {
        "id": "vehicle-crash-test",
        "name": "Vehicle crash test",
        "aka": [
          "crash test",
          "post-crash safety",
          "FMVSS 305"
        ],
        "section": "topic-testing",
        "definition": "Crashing a complete vehicle into a barrier, or striking it with a moving one, then checking that the battery stays in place, spills no electrolyte into the cabin and leaves no electric-shock hazard — voltage below 60 V DC or isolation intact. UN R94 and R95 and the US FMVSS 305 set these post-crash requirements.",
        "related": [
          "crush-test",
          "un-r100-part-2",
          "enclosure",
          "insulation-resistance",
          "pyrofuse",
          "fmvss-305a"
        ],
        "url": "https://lemonergy.com/learn/glossary/vehicle-crash-test/",
        "mentions": [
          "electrolyte"
        ]
      }
    }
  ]
}