{
  "node": {
    "id": "term:parallel-string-current-sharing",
    "type": "Term",
    "label": "Current sharing between parallel strings",
    "properties": {
      "id": "parallel-string-current-sharing",
      "name": "Current sharing between parallel strings",
      "aka": [
        "cross-string current sharing",
        "string current imbalance",
        "circulating current"
      ],
      "section": "topic-pack",
      "definition": "How current divides between strings connected in parallel. A string with lower resistance or a different OCV takes more than its share and ages faster, and connecting strings at different voltages drives a circulating current between them. Systems therefore match voltages before closing a string’s contactors and limit total current to what the weakest string can carry.",
      "related": [
        "string",
        "series-parallel",
        "internal-resistance",
        "open-circuit-voltage",
        "contactor",
        "cell-to-cell-variation"
      ],
      "url": "https://lemonergy.com/learn/glossary/parallel-string-current-sharing/",
      "mentions": []
    }
  },
  "edges": [
    {
      "id": "edge:5010",
      "source": "term:parallel-string-current-sharing",
      "target": "topic:topic-pack",
      "type": "belongsTo",
      "properties": {
        "sourceFile": "terms.json"
      }
    },
    {
      "id": "edge:5011",
      "source": "term:parallel-string-current-sharing",
      "target": "term:string",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:5012",
      "source": "term:parallel-string-current-sharing",
      "target": "term:series-parallel",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:5013",
      "source": "term:parallel-string-current-sharing",
      "target": "term:internal-resistance",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:5014",
      "source": "term:parallel-string-current-sharing",
      "target": "term:open-circuit-voltage",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:5015",
      "source": "term:parallel-string-current-sharing",
      "target": "term:contactor",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:5016",
      "source": "term:parallel-string-current-sharing",
      "target": "term:cell-to-cell-variation",
      "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:string",
      "type": "Term",
      "label": "String",
      "properties": {
        "id": "string",
        "name": "String",
        "aka": [
          "battery string",
          "series string"
        ],
        "section": "topic-pack",
        "definition": "A chain of cells or modules connected in series to reach the system voltage, the basic electrical unit of a large battery. In stationary storage each rack is usually one string of about 1000–1500 V with its own contactors and BMS, and many strings are paralleled on a common DC bus.",
        "related": [
          "series-parallel",
          "pack-voltage",
          "stationary-storage",
          "parallel-string-current-sharing",
          "bms-architecture",
          "contactor"
        ],
        "url": "https://lemonergy.com/learn/glossary/string/",
        "mentions": [
          "bms"
        ]
      }
    },
    {
      "id": "term:series-parallel",
      "type": "Term",
      "label": "Series and parallel connection",
      "properties": {
        "id": "series-parallel",
        "name": "Series and parallel connection",
        "aka": [
          "xSyP"
        ],
        "section": "topic-pack",
        "definition": "Cells in series add their voltages; cells in parallel add their capacities and share current. A pack is described as, for example, 96s4p: 96 groups in series, each of 4 cells in parallel. Series strings need balancing; parallel groups self-balance through their shared terminals.",
        "formula": "V = n_s·V_cell, Q = n_p·Q_cell",
        "related": [
          "module",
          "cell-balancing",
          "pack-voltage",
          "volt",
          "fuse"
        ],
        "lesson": "fundamentals/battery-basics/#cell-module-pack",
        "example": {
          "title": "Assemble an ideal 4s2p pack",
          "text": "Eight identical 3.6 V, 5 Ah cells arranged as four series groups with two cells in parallel give 14.4 V nominal, 10 Ah and 144 Wh. Interconnect losses, cell variation and usable voltage limits are additional constraints."
        },
        "url": "https://lemonergy.com/learn/glossary/series-parallel/",
        "mentions": []
      }
    },
    {
      "id": "term:internal-resistance",
      "type": "Term",
      "label": "Internal resistance",
      "properties": {
        "id": "internal-resistance",
        "name": "Internal resistance",
        "abbr": "IR",
        "aka": [
          "DC resistance",
          "DCIR"
        ],
        "section": "topic-units",
        "definition": "The resistance a cell presents to current, from its foils, electrolyte, interfaces and the reactions themselves. It converts part of the delivered energy into heat, sets the voltage drop under load, and rises as the cell ages; a large automotive cell has about a milliohm, a small cylindrical cell tens.",
        "unit": "mΩ",
        "related": [
          "ohms-law",
          "ir-drop",
          "impedance-rise",
          "dcir",
          "area-specific-resistance",
          "resistance-capacity-product"
        ],
        "lesson": "fundamentals/battery-basics/#datasheet",
        "url": "https://lemonergy.com/learn/glossary/internal-resistance/",
        "mentions": [
          "electrolyte",
          "cylindrical-cell"
        ]
      }
    },
    {
      "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": "term:contactor",
      "type": "Term",
      "label": "Contactor",
      "properties": {
        "id": "contactor",
        "name": "Contactor",
        "section": "topic-hvsafety",
        "definition": "A heavy-duty electrically operated switch that connects the pack to the vehicle or inverter and opens it on fault or shutdown. Packs use at least two, one per pole, plus a pre-charge path to avoid welding them on the first connection.",
        "related": [
          "pre-charge",
          "battery-disconnect-unit",
          "pyrofuse",
          "bms"
        ],
        "url": "https://lemonergy.com/learn/glossary/contactor/",
        "mentions": [
          "inverter"
        ]
      }
    },
    {
      "id": "term:cell-to-cell-variation",
      "type": "Term",
      "label": "Cell-to-cell variation",
      "properties": {
        "id": "cell-to-cell-variation",
        "name": "Cell-to-cell variation",
        "section": "topic-state",
        "definition": "The spread in capacity, resistance and self-discharge between nominally identical cells, from manufacturing and from unequal temperatures in service. It is why packs need balancing and why grading matches cells before assembly.",
        "related": [
          "cell-balancing",
          "grading",
          "end-of-line-testing",
          "thermal-management"
        ],
        "url": "https://lemonergy.com/learn/glossary/cell-to-cell-variation/",
        "mentions": [
          "self-discharge"
        ]
      }
    }
  ]
}