{
  "node": {
    "id": "term:vrla",
    "type": "Term",
    "label": "Valve-regulated lead–acid",
    "properties": {
      "id": "vrla",
      "name": "Valve-regulated lead–acid",
      "abbr": "VRLA",
      "aka": [
        "sealed lead–acid",
        "SLA",
        "AGM",
        "gel battery"
      ],
      "section": "topic-other-chemistries",
      "definition": "A lead–acid battery whose electrolyte is immobilised in glass-fibre mats (AGM) or a gel, with a pressure valve instead of open vents, so it can be used in any orientation without maintenance. It recombines the gases of overcharge internally.",
      "related": [
        "lead-acid",
        "flooded-lead-acid",
        "sulfation",
        "auxiliary-battery"
      ],
      "url": "https://lemonergy.com/learn/glossary/vrla/",
      "mentions": [
        "electrolyte",
        "overcharge"
      ]
    }
  },
  "edges": [
    {
      "id": "edge:3602",
      "source": "term:vrla",
      "target": "topic:topic-other-chemistries",
      "type": "belongsTo",
      "properties": {
        "sourceFile": "terms.json"
      }
    },
    {
      "id": "edge:3603",
      "source": "term:vrla",
      "target": "term:lead-acid",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:3604",
      "source": "term:vrla",
      "target": "term:flooded-lead-acid",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:3605",
      "source": "term:vrla",
      "target": "term:sulfation",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:3606",
      "source": "term:vrla",
      "target": "term:auxiliary-battery",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:mentions/vrla/electrolyte",
      "source": "term:vrla",
      "target": "term:electrolyte",
      "type": "mentions",
      "properties": {
        "sourceFile": "terms.json",
        "method": "build_glossary.mention_index + mentions",
        "field": "definition",
        "meaning": "Text mention; not a causal claim"
      }
    },
    {
      "id": "edge:mentions/vrla/overcharge",
      "source": "term:vrla",
      "target": "term:overcharge",
      "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-other-chemistries",
      "type": "Topic",
      "label": "Other and emerging chemistries",
      "properties": {
        "id": "topic-other-chemistries",
        "name": "Other and emerging chemistries",
        "lede": "Batteries beyond today’s lithium-ion: lead, nickel and primary cells, flow and metal–air batteries, solid-state and lithium-metal cells, and the multivalent and sodium chemistries in development.",
        "context": "Do not carry lithium-ion assumptions into every chemistry.",
        "example": "Two chemistries can meet the same energy target with different voltage windows and charge termination.",
        "lesson_url": "https://lemonergy.com/learn/fundamentals/cell-anatomy/",
        "lesson_label": "Open cell anatomy"
      }
    },
    {
      "id": "term:lead-acid",
      "type": "Term",
      "label": "Lead–acid battery",
      "properties": {
        "id": "lead-acid",
        "name": "Lead–acid battery",
        "section": "topic-other-chemistries",
        "definition": "The oldest rechargeable chemistry, lead and lead dioxide electrodes in sulfuric acid, at 2 V per cell. Heavy and short-lived in deep cycling but cheap, recyclable and good at cold cranking, it still starts most cars and backs up most telecom sites.",
        "related": [
          "nominal-voltage",
          "recycling",
          "specific-energy"
        ],
        "lesson": "labs/battery-materials-lab/#bml-market",
        "url": "https://lemonergy.com/learn/glossary/lead-acid/",
        "mentions": []
      }
    },
    {
      "id": "term:flooded-lead-acid",
      "type": "Term",
      "label": "Flooded lead–acid",
      "properties": {
        "id": "flooded-lead-acid",
        "name": "Flooded lead–acid",
        "aka": [
          "vented lead–acid",
          "wet cell"
        ],
        "section": "topic-other-chemistries",
        "definition": "The traditional lead–acid construction with free liquid electrolyte, vents and removable caps for topping up with water. It is cheap and tolerant of overcharge but must stay upright and be maintained.",
        "related": [
          "lead-acid",
          "vrla",
          "equalization-charge",
          "sulfation"
        ],
        "url": "https://lemonergy.com/learn/glossary/flooded-lead-acid/",
        "mentions": [
          "electrolyte",
          "overcharge"
        ]
      }
    },
    {
      "id": "term:sulfation",
      "type": "Term",
      "label": "Sulfation",
      "properties": {
        "id": "sulfation",
        "name": "Sulfation",
        "section": "topic-other-chemistries",
        "definition": "The growth of hard lead sulfate crystals on lead–acid plates when a battery is left discharged, which no longer convert back on charging. It is the usual way a neglected lead–acid battery dies, and has no counterpart in lithium-ion.",
        "related": [
          "lead-acid",
          "vrla",
          "flooded-lead-acid",
          "storage-soc"
        ],
        "url": "https://lemonergy.com/learn/glossary/sulfation/",
        "mentions": []
      }
    },
    {
      "id": "term:auxiliary-battery",
      "type": "Term",
      "label": "Auxiliary battery",
      "properties": {
        "id": "auxiliary-battery",
        "name": "Auxiliary battery",
        "aka": [
          "12 V battery",
          "low-voltage battery"
        ],
        "section": "topic-pack",
        "definition": "The small 12 V or 48 V battery in an electric vehicle that powers the controllers, lights and locks and wakes the BMS, kept charged from the high-voltage pack through a DC/DC converter. A flat auxiliary battery immobilises the car however full the main pack is.",
        "related": [
          "dc-dc-converter",
          "lead-acid",
          "pack",
          "lin-bus"
        ],
        "url": "https://lemonergy.com/learn/glossary/auxiliary-battery/",
        "mentions": [
          "bms",
          "electric-vehicle"
        ]
      }
    },
    {
      "id": "term:electrolyte",
      "type": "Term",
      "label": "Electrolyte",
      "properties": {
        "id": "electrolyte",
        "name": "Electrolyte",
        "section": "topic-electrolytes",
        "definition": "The ion-conducting medium between the electrodes. In a liquid-electrolyte cell it fills the pores of both electrodes and the separator, so it is not a separate structural layer.",
        "related": [
          "lithium-salt",
          "carbonate-solvent",
          "electrolyte-additive",
          "ionic-conductivity",
          "solid-electrolyte",
          "ionic-liquid-electrolyte"
        ],
        "lesson": "fundamentals/cell-architecture/#electrolyte",
        "example": {
          "title": "Ions and electrons",
          "text": "Electrolyte carries ions between electrodes; the external circuit carries electrons. The two paths serve different roles."
        },
        "url": "https://lemonergy.com/learn/glossary/electrolyte/",
        "mentions": [
          "separator"
        ]
      }
    },
    {
      "id": "term:overcharge",
      "type": "Term",
      "label": "Overcharge",
      "properties": {
        "id": "overcharge",
        "name": "Overcharge",
        "section": "topic-charging",
        "definition": "Charging past the upper cutoff voltage. The positive electrode over-delithiates and releases oxygen, the electrolyte oxidises and lithium plates on the negative, so an unprotected overcharge can end in thermal runaway.",
        "related": [
          "cutoff-voltage",
          "thermal-runaway",
          "bms",
          "overcharge-test",
          "electrolyte-decomposition"
        ],
        "url": "https://lemonergy.com/learn/glossary/overcharge/",
        "mentions": [
          "electrode",
          "positive-electrode",
          "electrolyte"
        ]
      }
    }
  ]
}