{
  "node": {
    "id": "term:soc-indicator",
    "type": "Term",
    "label": "State-of-charge indicator",
    "properties": {
      "id": "soc-indicator",
      "name": "State-of-charge indicator",
      "aka": [
        "LED fuel gauge",
        "battery level indicator",
        "push-button gauge",
        "SOCI"
      ],
      "section": "topic-pack",
      "definition": "The row of LEDs or small display on a battery pack that shows remaining charge, often lit by a push button to save energy. Four or five LEDs, each worth 20–25 %, are usual. It is only as accurate as the fuel gauge behind it; a voltage-only gauge reads badly on a flat curve such as LFP’s.",
      "related": [
        "fuel-gauge",
        "state-of-charge",
        "gpio",
        "lfp"
      ],
      "url": "https://lemonergy.com/learn/glossary/soc-indicator/",
      "mentions": []
    }
  },
  "edges": [
    {
      "id": "edge:belongsTo/term:soc-indicator/topic:topic-pack",
      "source": "term:soc-indicator",
      "target": "topic:topic-pack",
      "type": "belongsTo",
      "properties": {
        "sourceFile": "terms.json"
      }
    },
    {
      "id": "edge:relatedTo/term:soc-indicator/term:fuel-gauge",
      "source": "term:soc-indicator",
      "target": "term:fuel-gauge",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:relatedTo/term:soc-indicator/term:state-of-charge",
      "source": "term:soc-indicator",
      "target": "term:state-of-charge",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:relatedTo/term:soc-indicator/term:gpio",
      "source": "term:soc-indicator",
      "target": "term:gpio",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:relatedTo/term:soc-indicator/term:lfp",
      "source": "term:soc-indicator",
      "target": "term:lfp",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; 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:fuel-gauge",
      "type": "Term",
      "label": "Fuel gauge",
      "properties": {
        "id": "fuel-gauge",
        "name": "Fuel gauge",
        "aka": [
          "gas gauge"
        ],
        "section": "topic-pack",
        "definition": "The single chip in a phone, laptop or power tool that does the BMS’s state-estimation job for one or a few cells: coulomb counting corrected by an OCV model, with impedance tracking in better parts. It reports remaining capacity over SMBus or I²C.",
        "related": [
          "coulomb-counting",
          "state-of-charge",
          "smbus",
          "consumer-electronics",
          "afe",
          "soc-indicator"
        ],
        "url": "https://lemonergy.com/learn/glossary/fuel-gauge/",
        "mentions": [
          "coulomb",
          "impedance",
          "open-circuit-voltage",
          "bms"
        ]
      }
    },
    {
      "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"
        ]
      }
    },
    {
      "id": "term:gpio",
      "type": "Term",
      "label": "GPIO",
      "properties": {
        "id": "gpio",
        "name": "GPIO",
        "aka": [
          "general-purpose input/output",
          "GPIO pin"
        ],
        "section": "topic-data",
        "definition": "A microcontroller pin that firmware can configure as a digital input or output for whatever the design needs. In a battery pack GPIOs drive LED gauges, read a button or presence contact, enable a charger or regulator and switch between battery banks, so one pack design can serve several products.",
        "related": [
          "mcu",
          "firmware",
          "soc-indicator",
          "i2c",
          "embedded-charger"
        ],
        "url": "https://lemonergy.com/learn/glossary/gpio/",
        "mentions": [
          "charger"
        ]
      }
    },
    {
      "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"
        ]
      }
    }
  ]
}