{
"node": {
"id": "term:capacitor",
"type": "Term",
"label": "Capacitor",
"properties": {
"id": "capacitor",
"name": "Capacitor",
"section": "topic-units",
"definition": "A component that stores energy as charge on two conducting plates separated by an insulator; its voltage rises in proportion to the charge, unlike a battery’s nearly flat curve. The large DC-link capacitors at an inverter’s input draw a huge inrush current when connected to a pack, which is why a pre-charge circuit fills them first.",
"formula": "Q = C·V; E = ½·C·V²",
"unit": "F (farad)",
"related": [
"pre-charge",
"inverter",
"supercapacitor",
"double-layer",
"contactor"
],
"example": {
"title": "Calculate stored charge and energy",
"text": "An ideal 100 F capacitor charged to 2 V stores 200 C and 200 J. Doubling voltage quadruples its stored energy when capacitance remains constant."
},
"url": "https://lemonergy.com/learn/glossary/capacitor/",
"mentions": [
"inrush-current"
]
}
},
"edges": [
{
"id": "edge:165",
"source": "term:capacitor",
"target": "workflow:rc-response",
"type": "usedIn",
"properties": {
"sourceFile": "wiki-blocks.json"
}
},
{
"id": "edge:5668",
"source": "term:capacitor",
"target": "topic:topic-units",
"type": "belongsTo",
"properties": {
"sourceFile": "terms.json"
}
},
{
"id": "edge:5669",
"source": "term:capacitor",
"target": "term:pre-charge",
"type": "relatedTo",
"properties": {
"sourceFile": "terms.json",
"meaning": "Related context; not a causal claim"
}
},
{
"id": "edge:5670",
"source": "term:capacitor",
"target": "term:inverter",
"type": "relatedTo",
"properties": {
"sourceFile": "terms.json",
"meaning": "Related context; not a causal claim"
}
},
{
"id": "edge:5671",
"source": "term:capacitor",
"target": "term:supercapacitor",
"type": "relatedTo",
"properties": {
"sourceFile": "terms.json",
"meaning": "Related context; not a causal claim"
}
},
{
"id": "edge:5672",
"source": "term:capacitor",
"target": "term:double-layer",
"type": "relatedTo",
"properties": {
"sourceFile": "terms.json",
"meaning": "Related context; not a causal claim"
}
},
{
"id": "edge:5673",
"source": "term:capacitor",
"target": "term:contactor",
"type": "relatedTo",
"properties": {
"sourceFile": "terms.json",
"meaning": "Related context; not a causal claim"
}
},
{
"id": "edge:mentions/capacitor/inrush-current",
"source": "term:capacitor",
"target": "term:inrush-current",
"type": "mentions",
"properties": {
"sourceFile": "terms.json",
"method": "build_glossary.mention_index + mentions",
"field": "definition",
"meaning": "Text mention; not a causal claim"
}
},
{
"id": "edge:5675",
"source": "term:capacitor",
"target": "visual:capacitor",
"type": "illustratedBy",
"properties": {
"sourceFile": "visual-pages.json"
}
}
],
"neighbors": [
{
"id": "workflow:rc-response",
"type": "Workflow",
"label": "Observe an RC time constant",
"properties": {
"id": "rc-response",
"title": "Observe an RC time constant",
"kind": "studio",
"summary": "An RC circuit uses source, resistor, capacitor and reference blocks.",
"steps": [
"Keep R = 1 Ω and C = 1 F.",
"Inspect capacitor voltage after one and two time constants."
],
"example": "From zero initial voltage with a 1 V step, ideal capacitor voltage is about 0.632 V at 1 s and 0.865 V at 2 s.",
"observe": "Doubling resistance or capacitance doubles the time constant.",
"limits": "This generic circuit does not identify cell parameters from measurements.",
"url": "https://design.lemonergy.com/cosim.html?example=physical-rc",
"label": "Open the RC example",
"evidence": [
"js/physical-network.js",
"js/studio-examples.js"
]
}
},
{
"id": "topic:topic-units",
"type": "Topic",
"label": "Units and electrical basics",
"properties": {
"id": "topic-units",
"name": "Units and electrical basics",
"lede": "The quantities every datasheet is written in, and how they relate.",
"context": "Use consistent units and cell/pack basis.",
"example": "10 A for 30 min transfers 5 Ah. At constant 3.6 V this is 18 Wh; varying voltage requires integration.",
"lesson_url": "https://lemonergy.com/learn/fundamentals/capacity-and-c-rate/",
"lesson_label": "Open capacity and C-rate"
}
},
{
"id": "term:pre-charge",
"type": "Term",
"label": "Pre-charge circuit",
"properties": {
"id": "pre-charge",
"name": "Pre-charge circuit",
"section": "topic-hvsafety",
"definition": "A resistor and small contactor that charge the inverter’s capacitors slowly before the main contactor closes. Without it the inrush into empty capacitors can reach thousands of amperes and weld the main contactor shut.",
"related": [
"contactor",
"battery-disconnect-unit",
"inverter"
],
"url": "https://lemonergy.com/learn/glossary/pre-charge/",
"mentions": [
"inrush-current"
]
}
},
{
"id": "term:inverter",
"type": "Term",
"label": "Inverter",
"properties": {
"id": "inverter",
"name": "Inverter",
"aka": [
"power conversion system",
"PCS"
],
"section": "topic-pack",
"definition": "The power electronics that turn the battery’s DC into AC for a motor or the grid, and back again for charging. In stationary storage it is called the power conversion system and its rating in kW or MW sets the system’s power independently of the battery’s energy.",
"related": [
"pre-charge",
"dc-dc-converter",
"stationary-storage",
"energy-management-system",
"direct-current",
"iec-62477-1"
],
"url": "https://lemonergy.com/learn/glossary/inverter/",
"mentions": []
}
},
{
"id": "term:supercapacitor",
"type": "Term",
"label": "Supercapacitor",
"properties": {
"id": "supercapacitor",
"name": "Supercapacitor",
"aka": [
"ultracapacitor",
"EDLC"
],
"section": "topic-electrochemistry",
"definition": "A device that stores charge in the electric double layer on high-surface-area carbon rather than in a reaction. It delivers very high power and lasts a million cycles but stores only a few watt-hours per kilogram.",
"related": [
"double-layer",
"specific-power",
"ragone-plot",
"hybrid-energy-storage-system"
],
"url": "https://lemonergy.com/learn/glossary/supercapacitor/",
"mentions": []
}
},
{
"id": "term:double-layer",
"type": "Term",
"label": "Electric double layer",
"properties": {
"id": "double-layer",
"name": "Electric double layer",
"section": "topic-electrochemistry",
"definition": "The thin region at an electrode surface where ions in the electrolyte line up against the charge on the electrode, behaving like a capacitor. It stores a little charge without any reaction and shapes the high-frequency part of an impedance spectrum.",
"related": [
"charge-transfer",
"electrochemical-impedance-spectroscopy",
"supercapacitor"
],
"url": "https://lemonergy.com/learn/glossary/double-layer/",
"mentions": [
"impedance",
"electrode",
"electrolyte",
"capacitor"
]
}
},
{
"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:inrush-current",
"type": "Term",
"label": "Inrush current",
"properties": {
"id": "inrush-current",
"name": "Inrush current",
"aka": [
"inrush",
"surge current",
"switch-on surge"
],
"section": "topic-hvsafety",
"definition": "The brief current peak when a circuit is first energised, before its capacitors have charged or its magnetic parts have settled. Connected straight to a pack, an inverter’s empty DC-link capacitors would draw thousands of amperes, so a pre-charge circuit brings them to about 95% of pack voltage before the main contactor closes.",
"related": [
"pre-charge",
"contactor",
"inverter",
"blanking-delay",
"fuse-coordination"
],
"url": "https://lemonergy.com/learn/glossary/inrush-current/",
"mentions": [
"pack-voltage"
]
}
},
{
"id": "visual:capacitor",
"type": "Visual",
"label": "Capacitor charge and energy",
"properties": {
"title": "Capacitor charge and energy",
"summary": "Charge rises linearly with voltage; energy rises with voltage squared.",
"readout": "At 5 V: 25 C and 62.5 J.",
"formula": "Q = CV; E = ½CV²",
"note": "Ideal constant capacitance; leakage, series resistance and voltage rating excluded.",
"software": {
"status": "reference",
"label": "Reference concept",
"body": "Q = CV and E = ½CV² explain capacitor storage. The battery nominal-energy helper alone does not simulate capacitor precharge.",
"href": "../fundamentals/battery-basics/"
},
"html": "Stored charge