{
  "node": {
    "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"
      ]
    }
  },
  "edges": [
    {
      "id": "edge:159",
      "source": "term:current-sensor",
      "target": "workflow:ohm-circuit",
      "type": "usedIn",
      "properties": {
        "sourceFile": "wiki-blocks.json"
      }
    },
    {
      "id": "edge:2872",
      "source": "term:current-sensor",
      "target": "topic:topic-pack",
      "type": "belongsTo",
      "properties": {
        "sourceFile": "terms.json"
      }
    },
    {
      "id": "edge:2873",
      "source": "term:current-sensor",
      "target": "term:coulomb-counting",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:2874",
      "source": "term:current-sensor",
      "target": "term:bms",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:2875",
      "source": "term:current-sensor",
      "target": "term:battery-disconnect-unit",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:2876",
      "source": "term:current-sensor",
      "target": "term:state-of-charge",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:mentions/current-sensor/coulomb",
      "source": "term:current-sensor",
      "target": "term:coulomb",
      "type": "mentions",
      "properties": {
        "sourceFile": "terms.json",
        "method": "build_glossary.mention_index + mentions",
        "field": "definition",
        "meaning": "Text mention; not a causal claim"
      }
    },
    {
      "id": "edge:mentions/current-sensor/open-circuit-voltage",
      "source": "term:current-sensor",
      "target": "term:open-circuit-voltage",
      "type": "mentions",
      "properties": {
        "sourceFile": "terms.json",
        "method": "build_glossary.mention_index + mentions",
        "field": "definition",
        "meaning": "Text mention; not a causal claim"
      }
    },
    {
      "id": "edge:2879",
      "source": "term:current-sensor",
      "target": "reference:ti-bms",
      "type": "cites",
      "properties": {
        "sourceFile": "wiki-references.json",
        "scope": "direct technical reference"
      }
    }
  ],
  "neighbors": [
    {
      "id": "workflow:ohm-circuit",
      "type": "Workflow",
      "label": "Relate current and voltage",
      "properties": {
        "id": "ohm-circuit",
        "title": "Relate current and voltage",
        "kind": "studio",
        "summary": "Conserving components solve constitutive relations and node balance.",
        "steps": [
          "Inspect source and resistor in the RC example.",
          "Compare branch current with resistor voltage."
        ],
        "example": "A 1 V drop across 2 Ω implies 0.5 A.",
        "observe": "Topology sets individual element voltages.",
        "limits": "The RC example includes a capacitor: transient current varies and source voltage is not always resistor voltage.",
        "url": "https://design.lemonergy.com/cosim.html?example=physical-rc",
        "label": "Open the electrical circuit",
        "evidence": [
          "js/physical-network.js",
          "js/studio-examples.js"
        ]
      }
    },
    {
      "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: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:bms",
      "type": "Term",
      "label": "Battery management system",
      "properties": {
        "id": "bms",
        "name": "Battery management system",
        "abbr": "BMS",
        "section": "topic-pack",
        "definition": "The electronics and software that keep a battery inside its safe window: measuring every cell voltage and many temperatures, estimating SOC and SOH, balancing cells, computing current limits, controlling the contactors and reporting over the vehicle network.",
        "related": [
          "state-of-charge",
          "cell-balancing",
          "state-of-power",
          "cell-supervision-circuit",
          "contactor",
          "can-bus"
        ],
        "lesson": "fundamentals/battery-basics/#cell-module-pack",
        "url": "https://lemonergy.com/learn/glossary/bms/",
        "mentions": [
          "state-of-health",
          "cell-voltage"
        ]
      }
    },
    {
      "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: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"
        ]
      }
    },
    {
      "id": "term:open-circuit-voltage",
      "type": "Term",
      "label": "Open-circuit voltage",
      "properties": {
        "id": "open-circuit-voltage",
        "name": "Open-circuit voltage",
        "abbr": "OCV",
        "section": "topic-state",
        "definition": "The voltage across a cell’s terminals when no current flows and the cell has rested long enough for the voltage to settle. It depends on state of charge and temperature, and a cell whose open-circuit voltage falls unusually fast in storage may have an internal short.",
        "unit": "V",
        "related": [
          "ocv-soc-curve",
          "relaxation",
          "voltage-hysteresis",
          "k-value",
          "internal-short-circuit"
        ],
        "lesson": "fundamentals/cell-production/#finishing",
        "url": "https://lemonergy.com/learn/glossary/open-circuit-voltage/",
        "mentions": [
          "state-of-charge"
        ]
      }
    },
    {
      "id": "reference:ti-bms",
      "type": "Reference",
      "label": "Getting Started with the BQ76925",
      "properties": {
        "title": "Getting Started with the BQ76925",
        "publisher": "Texas Instruments",
        "url": "https://www.ti.com/lit/an/slua619b/slua619b.pdf",
        "type": "Application report",
        "scope": "A concrete BMS analog front-end example: cell voltage, current, temperature measurement and MCU integration.",
        "year": 2019,
        "accessed": "2026-10-27"
      }
    }
  ]
}