{
  "node": {
    "id": "term:thermoelectric-error",
    "type": "Term",
    "label": "Thermoelectric voltage error",
    "properties": {
      "id": "thermoelectric-error",
      "name": "Thermoelectric voltage error",
      "aka": [
        "Seebeck error",
        "thermal EMF",
        "thermocouple effect"
      ],
      "section": "topic-data",
      "definition": "A small voltage, the Seebeck effect, that appears wherever two different metals meet at different temperatures. Negligible for cell voltages, it matters for shunt current sensing: on a 100 µΩ shunt each microvolt reads as 10 mA, which coulomb counting integrates into SOC drift. Manganin is used for shunts partly because its thermal EMF against copper is under 1 µV/K.",
      "related": [
        "current-sensor",
        "coulomb-counting",
        "adc",
        "kelvin-sensing",
        "state-of-charge"
      ],
      "url": "https://lemonergy.com/learn/glossary/thermoelectric-error/",
      "mentions": [
        "coulomb"
      ]
    }
  },
  "edges": [
    {
      "id": "edge:5277",
      "source": "term:thermoelectric-error",
      "target": "topic:topic-data",
      "type": "belongsTo",
      "properties": {
        "sourceFile": "terms.json"
      }
    },
    {
      "id": "edge:5278",
      "source": "term:thermoelectric-error",
      "target": "term:current-sensor",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:5279",
      "source": "term:thermoelectric-error",
      "target": "term:coulomb-counting",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:5280",
      "source": "term:thermoelectric-error",
      "target": "term:adc",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:5281",
      "source": "term:thermoelectric-error",
      "target": "term:kelvin-sensing",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:5282",
      "source": "term:thermoelectric-error",
      "target": "term:state-of-charge",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:mentions/thermoelectric-error/coulomb",
      "source": "term:thermoelectric-error",
      "target": "term:coulomb",
      "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-data",
      "type": "Topic",
      "label": "Data, communication and electronics",
      "properties": {
        "id": "topic-data",
        "name": "Data, communication and electronics",
        "lede": "The control units, chips, protocols and file formats through which a battery is measured, controlled and logged.",
        "context": "Separate quantities from encoding and transport.",
        "example": "2500 in a log might mean 25.00 °C, 2.5 V or raw counts. Units and scale must accompany the value.",
        "lesson_url": "https://lemonergy.com/learn/fundamentals/battery-basics/",
        "lesson_label": "Open battery basics"
      }
    },
    {
      "id": "term:current-sensor",
      "type": "Term",
      "label": "Current sensor",
      "properties": {
        "id": "current-sensor",
        "name": "Current sensor",
        "aka": [
          "shunt",
          "Hall sensor"
        ],
        "section": "topic-pack",
        "definition": "The device that measures pack current for coulomb counting and protection: a precision shunt resistor read by an amplifier, or a Hall-effect sensor around the cable. Offset error in this sensor is what makes SOC drift between OCV corrections.",
        "related": [
          "coulomb-counting",
          "bms",
          "battery-disconnect-unit",
          "state-of-charge"
        ],
        "url": "https://lemonergy.com/learn/glossary/current-sensor/",
        "mentions": [
          "coulomb",
          "open-circuit-voltage"
        ]
      }
    },
    {
      "id": "term:coulomb-counting",
      "type": "Term",
      "label": "Coulomb counting",
      "properties": {
        "id": "coulomb-counting",
        "name": "Coulomb counting",
        "aka": [
          "ampere-hour counting"
        ],
        "section": "topic-state",
        "definition": "Estimating state of charge by integrating the measured current over time. Simple and fast, but sensor offset accumulates, so it is corrected against the OCV–SOC curve at rest or fused with it in a Kalman filter.",
        "formula": "SOC(t) = SOC₀ − ∫ I dt / Q",
        "related": [
          "state-of-charge",
          "ocv-soc-curve",
          "kalman-filter",
          "current-sensor"
        ],
        "example": {
          "title": "Integrate a discharge step",
          "text": "Starting at 80% SOC with a 5 Ah available capacity, an ideal 2 A discharge for 30 min removes 1 Ah and lowers SOC to 60%. This example takes discharge current as positive and ignores efficiency and sensor error."
        },
        "url": "https://lemonergy.com/learn/glossary/coulomb-counting/",
        "mentions": [
          "open-circuit-voltage"
        ]
      }
    },
    {
      "id": "term:adc",
      "type": "Term",
      "label": "Analog-to-digital converter",
      "properties": {
        "id": "adc",
        "name": "Analog-to-digital converter",
        "abbr": "ADC",
        "section": "topic-data",
        "definition": "The circuit that turns a voltage into a number. In a BMS its resolution, offset and drift set the floor for voltage and current accuracy: one millivolt of cell-voltage error is several percent of SOC on a flat LFP curve.",
        "related": [
          "afe",
          "current-sensor",
          "voltage-sense",
          "coulomb-counting",
          "ocv-soc-curve"
        ],
        "url": "https://lemonergy.com/learn/glossary/adc/",
        "mentions": [
          "state-of-charge",
          "bms"
        ]
      }
    },
    {
      "id": "term:kelvin-sensing",
      "type": "Term",
      "label": "Kelvin sensing",
      "properties": {
        "id": "kelvin-sensing",
        "name": "Kelvin sensing",
        "aka": [
          "four-wire sensing",
          "four-terminal sensing",
          "4-wire measurement",
          "separate sense and balancing leads"
        ],
        "section": "topic-data",
        "definition": "Measuring voltage through a separate pair of leads that carry no current, so the drop along current-carrying wires and joints is left out. In a BMS, 100 mA of balancing current through 0.5 Ω of sense wire would add a 50 mV error, so designs either give balancing its own leads or pause balancing while measuring.",
        "related": [
          "voltage-sense",
          "cell-balancing",
          "current-sensor",
          "contact-resistance",
          "dcir",
          "thermoelectric-error"
        ],
        "url": "https://lemonergy.com/learn/glossary/kelvin-sensing/",
        "mentions": [
          "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:coulomb",
      "type": "Term",
      "label": "Coulomb",
      "properties": {
        "id": "coulomb",
        "name": "Coulomb",
        "abbr": "C",
        "section": "topic-units",
        "definition": "The SI unit of electric charge; one ampere flowing for one second. Battery engineers prefer the ampere-hour, which is 3600 coulombs, because cells deliver their charge over hours.",
        "unit": "C",
        "related": [
          "ampere-hour",
          "faradays-constant"
        ],
        "url": "https://lemonergy.com/learn/glossary/coulomb/",
        "mentions": [
          "ampere",
          "electric-charge"
        ]
      }
    }
  ]
}