{
"node": {
"id": "term:cutoff-voltage",
"type": "Term",
"label": "Cutoff voltage",
"properties": {
"id": "cutoff-voltage",
"name": "Cutoff voltage",
"section": "topic-charging",
"definition": "The terminal-voltage limit that ends a discharge, or caps a charge — in constant-current, constant-voltage (CC-CV) charging the cell is then held at that voltage until the current falls to a cutoff. A real discharge ends at the lower cutoff, which is why actual runtime can differ from the ideal duration.",
"unit": "V",
"related": [
"voltage-window",
"cc-cv-charging",
"ideal-duration",
"over-discharge",
"overcharge"
],
"lesson": "fundamentals/capacity-and-c-rate/#real-cells",
"url": "https://lemonergy.com/learn/glossary/cutoff-voltage/",
"mentions": [
"service-life"
]
}
},
"edges": [
{
"id": "edge:39",
"source": "term:cutoff-voltage",
"target": "workflow:cccv",
"type": "usedIn",
"properties": {
"sourceFile": "wiki-blocks.json"
}
},
{
"id": "edge:1093",
"source": "term:cutoff-voltage",
"target": "topic:topic-charging",
"type": "belongsTo",
"properties": {
"sourceFile": "terms.json"
}
},
{
"id": "edge:1094",
"source": "term:cutoff-voltage",
"target": "term:voltage-window",
"type": "relatedTo",
"properties": {
"sourceFile": "terms.json",
"meaning": "Related context; not a causal claim"
}
},
{
"id": "edge:1095",
"source": "term:cutoff-voltage",
"target": "term:cc-cv-charging",
"type": "relatedTo",
"properties": {
"sourceFile": "terms.json",
"meaning": "Related context; not a causal claim"
}
},
{
"id": "edge:1096",
"source": "term:cutoff-voltage",
"target": "term:ideal-duration",
"type": "relatedTo",
"properties": {
"sourceFile": "terms.json",
"meaning": "Related context; not a causal claim"
}
},
{
"id": "edge:1097",
"source": "term:cutoff-voltage",
"target": "term:over-discharge",
"type": "relatedTo",
"properties": {
"sourceFile": "terms.json",
"meaning": "Related context; not a causal claim"
}
},
{
"id": "edge:1098",
"source": "term:cutoff-voltage",
"target": "term:overcharge",
"type": "relatedTo",
"properties": {
"sourceFile": "terms.json",
"meaning": "Related context; not a causal claim"
}
},
{
"id": "edge:mentions/cutoff-voltage/service-life",
"source": "term:cutoff-voltage",
"target": "term:service-life",
"type": "mentions",
"properties": {
"sourceFile": "terms.json",
"method": "build_glossary.mention_index + mentions",
"field": "definition",
"meaning": "Text mention; not a causal claim"
}
},
{
"id": "edge:1100",
"source": "term:cutoff-voltage",
"target": "lesson:fundamentals/capacity-and-c-rate/",
"type": "explainedIn",
"properties": {
"sourceFile": "terms.json",
"url": "https://lemonergy.com/learn/fundamentals/capacity-and-c-rate/#real-cells"
}
},
{
"id": "edge:1101",
"source": "term:cutoff-voltage",
"target": "visual:charging-cccv",
"type": "illustratedBy",
"properties": {
"sourceFile": "visual-pages.json"
}
}
],
"neighbors": [
{
"id": "workflow:cccv",
"type": "Workflow",
"label": "Build CC–CV charging",
"properties": {
"id": "cccv",
"title": "Build CC–CV charging",
"kind": "studio",
"summary": "Native current and voltage regulation act against an explicit battery.",
"steps": [
"Open home charging and inspect settings.",
"Choose immediate charging; inspect mode and completion."
],
"example": "An illustrative 100 Ah battery with a 420 V ceiling can use a 32 A cap. At the ceiling, current falls as OCV rises.",
"observe": "Completion needs current below cutoff at the CV ceiling for the configured dwell. Site-limited low current is different.",
"limits": "The battery uses linear OCV and fixed resistance. It does not automatically add aging, thermal dynamics or balancing.",
"url": "https://design.lemonergy.com/cosim.html?example=charging-home",
"label": "Open the Studio example",
"evidence": [
"js/charging-control.js",
"js/charging-scenarios.js",
"docs/CHARGING_BLOCKS_SPEC.md"
]
}
},
{
"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:voltage-window",
"type": "Term",
"label": "Voltage window",
"properties": {
"id": "voltage-window",
"name": "Voltage window",
"aka": [
"operating voltage range"
],
"section": "topic-ratings",
"definition": "The range between a cell’s lower and upper cutoff voltages, such as 2.5–4.2 V for an NMC/graphite cell. Staying inside it is what keeps the electrodes and electrolyte from degrading quickly.",
"unit": "V",
"related": [
"cutoff-voltage",
"overcharge",
"over-discharge",
"electrochemical-stability-window"
],
"url": "https://lemonergy.com/learn/glossary/voltage-window/",
"mentions": [
"graphite",
"electrolyte"
]
}
},
{
"id": "term:cc-cv-charging",
"type": "Term",
"label": "CC-CV charging",
"properties": {
"id": "cc-cv-charging",
"name": "CC-CV charging",
"aka": [
"constant current constant voltage"
],
"section": "topic-charging",
"definition": "The standard lithium-ion charge protocol: constant current until the cell reaches its upper cutoff voltage, then that voltage held constant while the current tapers. The charge ends when the current falls to a set fraction, often C/20.",
"related": [
"constant-current",
"constant-voltage",
"cutoff-voltage",
"taper-current",
"fast-charging",
"cp-cv"
],
"lesson": "fundamentals/capacity-and-c-rate/#real-cells",
"example": {
"title": "Follow a two-stage charge",
"text": "For an illustrative 5 Ah cell, a 2.5 A current request is 0.5C. During CC the voltage rises. At the selected upper voltage, CV regulation holds voltage while current tapers. Completion requires the taper current to fall below the selected cutoff for the configured dwell."
},
"notes": [
"Choose voltage, current and temperature limits from the actual cell specification. These example values do not define a charging recipe."
],
"url": "https://lemonergy.com/learn/glossary/cc-cv-charging/",
"mentions": []
}
},
{
"id": "term:ideal-duration",
"type": "Term",
"label": "Ideal duration",
"properties": {
"id": "ideal-duration",
"name": "Ideal duration",
"section": "topic-ratings",
"definition": "t = 1 / C-rate: how long a constant current would take to transfer the full nominal capacity. A definition, not a prediction of real runtime.",
"formula": "t = 1 / C-rate",
"unit": "h",
"related": [
"c-rate",
"cutoff-voltage",
"rate-capability"
],
"lesson": "fundamentals/capacity-and-c-rate/#area",
"example": {
"title": "Estimate an ideal duration",
"text": "At 0.5C, an ideal full-capacity constant-current discharge takes 1 / 0.5 = 2 h. A real discharge can end earlier at its voltage limit; CC-CV charging includes a taper and does not follow this duration alone."
},
"url": "https://lemonergy.com/learn/glossary/ideal-duration/",
"mentions": [
"nominal-capacity",
"constant-current",
"service-life"
]
}
},
{
"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: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"
]
}
},
{
"id": "term:service-life",
"type": "Term",
"label": "Service life",
"properties": {
"id": "service-life",
"name": "Service life",
"aka": [
"runtime"
],
"section": "topic-ratings",
"definition": "The total time a battery stays useful in its application, set by whichever of calendar life and cycle life runs out first. Runtime, by contrast, is the time a single charge lasts under a given load.",
"related": [
"calendar-life",
"cycle-life",
"end-of-life",
"warranty"
],
"url": "https://lemonergy.com/learn/glossary/service-life/",
"mentions": []
}
},
{
"id": "lesson:fundamentals/capacity-and-c-rate/",
"type": "Lesson",
"label": "Lesson 2 · Capacity and C-rate",
"properties": {
"url": "https://lemonergy.com/learn/fundamentals/capacity-and-c-rate/"
}
},
{
"id": "visual:charging-cccv",
"type": "Visual",
"label": "Compare charging profiles",
"properties": {
"title": "Compare charging profiles",
"summary": "See which quantity is held constant, when the phase changes and how charging ends.",
"readout": "Current holds at 5 A until the example 4.15 V threshold; voltage then holds while current tapers. The stop marker is a separate low-current termination condition.",
"formula": "CC: I = I_set · CV: V = V_limit",
"note": "Positive current charges the cell. Time is normalized; selected thresholds are not cell-specific recommendations. The voltage trace ends at termination; post-stop relaxation is excluded.",
"software": {
"status": "studio",
"label": "Lemonergy Studio charging controller",
"body": "The native controller regulates CC-CV charging. Its battery model uses charge balance, linear OCV and constant resistance. These authored profiles are explanatory, not its simulation output.",
"href": "https://design.lemonergy.com/cosim.html?example=charging-home"
},
"html": "Current profile