{
  "node": {
    "id": "term:critical-self-heating-temperature",
    "type": "Term",
    "label": "Critical self-heating temperature",
    "properties": {
      "id": "critical-self-heating-temperature",
      "name": "Critical self-heating temperature",
      "aka": [
        "critical temperature",
        "point of no return"
      ],
      "section": "topic-safety",
      "definition": "The highest temperature from which a cell, in its actual surroundings, can still cool back down; above it, self-heating outruns heat loss and thermal runaway follows even if the heat source is removed. Unlike the onset temperature, which is measured adiabatically, it depends on the installation: better cooling raises it, while larger cells and higher SOC lower it.",
      "related": [
        "onset-temperature",
        "thermal-runaway",
        "accelerating-rate-calorimetry",
        "thermal-management",
        "heat-generation"
      ],
      "url": "https://lemonergy.com/learn/glossary/critical-self-heating-temperature/",
      "mentions": [
        "state-of-charge"
      ]
    }
  },
  "edges": [
    {
      "id": "edge:6607",
      "source": "term:critical-self-heating-temperature",
      "target": "topic:topic-safety",
      "type": "belongsTo",
      "properties": {
        "sourceFile": "terms.json"
      }
    },
    {
      "id": "edge:6608",
      "source": "term:critical-self-heating-temperature",
      "target": "term:onset-temperature",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:6609",
      "source": "term:critical-self-heating-temperature",
      "target": "term:thermal-runaway",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:6610",
      "source": "term:critical-self-heating-temperature",
      "target": "term:accelerating-rate-calorimetry",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:6611",
      "source": "term:critical-self-heating-temperature",
      "target": "term:thermal-management",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:6612",
      "source": "term:critical-self-heating-temperature",
      "target": "term:heat-generation",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:mentions/critical-self-heating-temperature/state-of-charge",
      "source": "term:critical-self-heating-temperature",
      "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-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:onset-temperature",
      "type": "Term",
      "label": "Onset temperature",
      "properties": {
        "id": "onset-temperature",
        "name": "Onset temperature",
        "aka": [
          "self-heating onset"
        ],
        "section": "topic-safety",
        "definition": "The temperature at which a cell begins to generate heat by itself, as the SEI starts to decompose, typically 80–120 °C. Measured in an accelerating rate calorimeter, it marks the start of the path to thermal runaway, not the runaway itself.",
        "unit": "°C",
        "related": [
          "thermal-runaway",
          "accelerating-rate-calorimetry",
          "sei",
          "separator-shutdown",
          "critical-self-heating-temperature"
        ],
        "url": "https://lemonergy.com/learn/glossary/onset-temperature/",
        "mentions": []
      }
    },
    {
      "id": "term:thermal-runaway",
      "type": "Term",
      "label": "Thermal runaway",
      "properties": {
        "id": "thermal-runaway",
        "name": "Thermal runaway",
        "section": "topic-safety",
        "definition": "Self-accelerating heating in a cell: heat speeds up reactions that release more heat, until the cell vents, catches fire or ruptures. An internal short, overcharge or external heating can trigger it.",
        "related": [
          "onset-temperature",
          "thermal-propagation",
          "venting",
          "separator-shutdown",
          "thermal-runaway-energy",
          "exothermic"
        ],
        "lesson": "fundamentals/cell-anatomy/#short-circuit",
        "url": "https://lemonergy.com/learn/glossary/thermal-runaway/",
        "mentions": [
          "overcharge"
        ]
      }
    },
    {
      "id": "term:accelerating-rate-calorimetry",
      "type": "Term",
      "label": "Accelerating rate calorimetry",
      "properties": {
        "id": "accelerating-rate-calorimetry",
        "name": "Accelerating rate calorimetry",
        "abbr": "ARC",
        "section": "topic-safety",
        "definition": "A test in which a cell sits in an adiabatic chamber that follows its temperature, so any self-heating is not lost to the surroundings. It measures the onset temperature, the self-heating rate and the temperature at which runaway becomes unstoppable.",
        "related": [
          "onset-temperature",
          "thermal-runaway",
          "differential-scanning-calorimetry"
        ],
        "url": "https://lemonergy.com/learn/glossary/accelerating-rate-calorimetry/",
        "mentions": [
          "adiabatic-isothermal"
        ]
      }
    },
    {
      "id": "term:thermal-management",
      "type": "Term",
      "label": "Thermal management",
      "properties": {
        "id": "thermal-management",
        "name": "Thermal management",
        "abbr": "TMS",
        "aka": [
          "battery thermal management system",
          "BTMS"
        ],
        "section": "topic-thermal",
        "definition": "Keeping cells in their comfortable range, roughly 15–35 °C, and within a few degrees of each other: liquid cooling plates, refrigerant plates or immersion for heat removal, and heaters or waste heat for warming before fast charging in the cold.",
        "related": [
          "cooling-plate",
          "thermal-interface-material",
          "operating-temperature",
          "heat-generation",
          "preconditioning",
          "temperature-sensor"
        ],
        "url": "https://lemonergy.com/learn/glossary/thermal-management/",
        "mentions": [
          "fast-charging"
        ]
      }
    },
    {
      "id": "term:heat-generation",
      "type": "Term",
      "label": "Heat generation",
      "properties": {
        "id": "heat-generation",
        "name": "Heat generation",
        "aka": [
          "Bernardi equation"
        ],
        "section": "topic-thermal",
        "definition": "The heat a cell produces in operation: an irreversible part equal to current times overpotential, and a reversible part from the entropy change, I·T·dE/dT. The Bernardi equation sums them and feeds every thermal model.",
        "formula": "q = I(V − E_OCV) + I·T·(dE/dT)",
        "unit": "W",
        "related": [
          "entropy-coefficient",
          "internal-resistance",
          "thermal-model",
          "thermal-management",
          "exothermic"
        ],
        "example": {
          "title": "Keep reversible and irreversible heat separate",
          "text": "With charging current +5 A and terminal voltage 0.10 V above OCV, the irreversible term is 0.50 W. At 300 K with dE/dT = +0.1 mV/K, the reversible contribution is +0.15 W, giving 0.65 W under this sign convention."
        },
        "url": "https://lemonergy.com/learn/glossary/heat-generation/",
        "mentions": [
          "overpotential"
        ]
      }
    },
    {
      "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"
        ]
      }
    }
  ]
}