{
  "node": {
    "id": "term:cell-reversal",
    "type": "Term",
    "label": "Cell reversal",
    "properties": {
      "id": "cell-reversal",
      "name": "Cell reversal",
      "section": "topic-charging",
      "definition": "A weak cell in a series string being driven below zero volts by its neighbours as the string is discharged past the weak cell’s empty point. It causes rapid, permanent damage, and preventing it is one reason a BMS monitors every cell.",
      "related": [
        "over-discharge",
        "series-parallel",
        "bms",
        "polarity"
      ],
      "url": "https://lemonergy.com/learn/glossary/cell-reversal/",
      "mentions": [
        "string"
      ]
    }
  },
  "edges": [
    {
      "id": "edge:3586",
      "source": "term:cell-reversal",
      "target": "topic:topic-charging",
      "type": "belongsTo",
      "properties": {
        "sourceFile": "terms.json"
      }
    },
    {
      "id": "edge:3587",
      "source": "term:cell-reversal",
      "target": "term:over-discharge",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:3588",
      "source": "term:cell-reversal",
      "target": "term:series-parallel",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:3589",
      "source": "term:cell-reversal",
      "target": "term:bms",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:3590",
      "source": "term:cell-reversal",
      "target": "term:polarity",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:mentions/cell-reversal/string",
      "source": "term:cell-reversal",
      "target": "term:string",
      "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-charging",
      "type": "Topic",
      "label": "Charging and discharging",
      "properties": {
        "id": "topic-charging",
        "name": "Charging and discharging",
        "lede": "How current goes in and comes out, and the limits that stop it.",
        "context": "Separate regulation from availability.",
        "example": "The same CC–CV law can operate overnight or during a short depot stop.",
        "lesson_url": "https://lemonergy.com/learn/fundamentals/capacity-and-c-rate/",
        "lesson_label": "Open charging quantities"
      }
    },
    {
      "id": "term:over-discharge",
      "type": "Term",
      "label": "Over-discharge",
      "properties": {
        "id": "over-discharge",
        "name": "Over-discharge",
        "aka": [
          "deep discharge"
        ],
        "section": "topic-charging",
        "definition": "Discharging below the lower cutoff voltage. Near 1.5 V the copper current collector begins to dissolve, and on the next charge it can redeposit as metal that shorts the cell, so a deeply discharged cell should not simply be recharged.",
        "related": [
          "cutoff-voltage",
          "copper-dissolution",
          "internal-short-circuit",
          "bms",
          "low-voltage-disconnect"
        ],
        "url": "https://lemonergy.com/learn/glossary/over-discharge/",
        "mentions": [
          "current-collector"
        ]
      }
    },
    {
      "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: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:polarity",
      "type": "Term",
      "label": "Polarity",
      "properties": {
        "id": "polarity",
        "name": "Polarity",
        "aka": [
          "reverse polarity"
        ],
        "section": "topic-units",
        "definition": "Which terminal is positive and which negative. Connecting a cell or charger the wrong way round, reverse polarity, drives current backwards through it and can destroy the cell, the charger or both within seconds.",
        "related": [
          "terminal",
          "cell-reversal",
          "charger"
        ],
        "url": "https://lemonergy.com/learn/glossary/polarity/",
        "mentions": []
      }
    },
    {
      "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"
        ]
      }
    }
  ]
}