{ "node": { "id": "term:derating", "type": "Term", "label": "Derating", "properties": { "id": "derating", "name": "Derating", "section": "topic-pack", "definition": "Reducing the allowed charge or discharge power as the battery approaches a limit — low temperature, high temperature, high or low SOC, or age. It is how a BMS keeps the cells safe while letting the vehicle do as much as it can.", "related": [ "state-of-power", "bms", "operating-temperature", "fast-charging", "limp-home-mode" ], "url": "https://lemonergy.com/learn/glossary/derating/", "mentions": [ "state-of-charge" ] } }, "edges": [ { "id": "edge:150", "source": "term:derating", "target": "workflow:bounded-screen", "type": "usedIn", "properties": { "sourceFile": "wiki-blocks.json" } }, { "id": "edge:2974", "source": "term:derating", "target": "topic:topic-pack", "type": "belongsTo", "properties": { "sourceFile": "terms.json" } }, { "id": "edge:2975", "source": "term:derating", "target": "term:state-of-power", "type": "relatedTo", "properties": { "sourceFile": "terms.json", "meaning": "Related context; not a causal claim" } }, { "id": "edge:2976", "source": "term:derating", "target": "term:bms", "type": "relatedTo", "properties": { "sourceFile": "terms.json", "meaning": "Related context; not a causal claim" } }, { "id": "edge:2977", "source": "term:derating", "target": "term:operating-temperature", "type": "relatedTo", "properties": { "sourceFile": "terms.json", "meaning": "Related context; not a causal claim" } }, { "id": "edge:2978", "source": "term:derating", "target": "term:fast-charging", "type": "relatedTo", "properties": { "sourceFile": "terms.json", "meaning": "Related context; not a causal claim" } }, { "id": "edge:2979", "source": "term:derating", "target": "term:limp-home-mode", "type": "relatedTo", "properties": { "sourceFile": "terms.json", "meaning": "Related context; not a causal claim" } }, { "id": "edge:mentions/derating/state-of-charge", "source": "term:derating", "target": "term:state-of-charge", "type": "mentions", "properties": { "sourceFile": "terms.json", "method": "build_glossary.mention_index + mentions", "field": "definition", "meaning": "Text mention; not a causal claim" } }, { "id": "edge:2981", "source": "term:derating", "target": "visual:derating", "type": "illustratedBy", "properties": { "sourceFile": "visual-pages.json" } } ], "neighbors": [ { "id": "workflow:bounded-screen", "type": "Workflow", "label": "Stop at a declared limit", "properties": { "id": "bounded-screen", "title": "Stop at a declared limit", "kind": "protocol", "summary": "A discharge can end at temperature or voltage thresholds.", "steps": [ "Open Bounded discharge screening.", "Inspect endings and the reported stop reason." ], "example": "The template uses 30 A, 1800 s maximum, 45 °C and a 3.0 V cell floor to illustrate stopping.", "observe": "A threshold can end the run early.", "limits": "This simulated screen is not abuse testing or proof that the battery or protection system is safe.", "url": "https://design.lemonergy.com/", "label": "Open Design → Protocol bench", "evidence": [ "js/test-protocol.js" ] } }, { "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:state-of-power", "type": "Term", "label": "State of power", "properties": { "id": "state-of-power", "name": "State of power", "abbr": "SOP", "section": "topic-state", "definition": "The maximum charge or discharge power a battery can deliver for the next few seconds without breaking a voltage, current or temperature limit. The BMS recomputes it continuously from SOC, temperature and resistance and sends it to the motor controller.", "unit": "W", "related": [ "power", "state-of-charge", "continuous-current", "derating", "bms", "state-of-function" ], "url": "https://lemonergy.com/learn/glossary/state-of-power/", "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:operating-temperature", "type": "Term", "label": "Operating temperature", "properties": { "id": "operating-temperature", "name": "Operating temperature", "section": "topic-ratings", "definition": "The temperature range a cell may be charged and discharged in, typically 0–45 °C for charging and −20–60 °C for discharging. Charging below 0 °C risks lithium plating; above the range the cell ages fast and may vent.", "unit": "°C", "related": [ "lithium-plating", "arrhenius", "thermal-management", "datasheet" ], "lesson": "fundamentals/battery-aging/#temperature", "url": "https://lemonergy.com/learn/glossary/operating-temperature/", "mentions": [] } }, { "id": "term:fast-charging", "type": "Term", "label": "Fast charging", "properties": { "id": "fast-charging", "name": "Fast charging", "section": "topic-charging", "definition": "Charging intended to replenish a specified amount of energy or state of charge in a short time. There is no universal C-rate threshold: performance depends on cell chemistry, temperature, starting state and power limits. High current can increase heating and lithium-plating risk, requiring appropriate limits.", "related": [ "lithium-plating", "c-rate", "cc-cv-charging", "dc-fast-charging", "thermal-management", "mscc" ], "url": "https://lemonergy.com/learn/glossary/fast-charging/", "mentions": [ "state-of-charge" ] } }, { "id": "term:limp-home-mode", "type": "Term", "label": "Limp-home mode", "properties": { "id": "limp-home-mode", "name": "Limp-home mode", "aka": [ "limp mode", "fallback mode", "degraded mode" ], "section": "topic-data", "definition": "A reduced-performance state the vehicle or BMS enters after a fault that is not severe enough to shut down, such as a lost temperature sensor or a failed balancing channel. Power and charging are derated so the driver can reach safety or a workshop, and a fault code records why.", "related": [ "derating", "dtc", "state-of-power", "bms", "functional-safety" ], "url": "https://lemonergy.com/learn/glossary/limp-home-mode/", "mentions": [ "temperature-sensor" ] } }, { "id": "term:state-of-charge", "type": "Term", "label": "State of charge", "properties": { "id": "state-of-charge", "name": "State of charge", "abbr": "SOC", "section": "topic-state", "definition": "How full a cell is, as a fraction of its available capacity. State of charge, like temperature, affects how fast a stored cell ages.", "unit": "%", "related": [ "depth-of-discharge", "ocv-soc-curve", "coulomb-counting", "state-of-health", "bms" ], "lesson": "fundamentals/battery-aging/#storage-soc", "example": { "title": "Interpret a charge inventory", "text": "If available capacity is 5 Ah and 3 Ah remains by the chosen estimator, SOC is 60%. A different estimate of available capacity changes this percentage, so compare SOC values only with the capacity convention recorded." }, "url": "https://lemonergy.com/learn/glossary/state-of-charge/", "mentions": [ "usable-capacity" ] } }, { "id": "visual:derating", "type": "Visual", "label": "The limit sets the permitted current", "properties": { "title": "The limit sets the permitted current", "summary": "A requested current is clipped wherever an active limit is lower.", "readout": "Requested current: 8 A. At 50 °C the chosen limit permits 5 A.", "formula": "I_command = min(I_requested, I_limit)", "note": "Breakpoints are invented teaching values, not operating limits for a particular battery.", "software": { "status": "reference", "label": "Reference concept", "body": "A BMS can combine temperature, voltage and equipment limits. The selected breakpoints illustrate logic only; actual limits must be cell-specific.", "href": "https://lemonergy.com/wiki/charging-strategies/" }, "html": "
Illustrative temperature current limit
Illustrative temperature current limitTemperature (°C) versus Current (A). Limit; Permitted command. Interpretation follows the graphs.0-1037.5625942.51260Temperature (°C)Current (A)
LimitPermitted command (dashed)
" } } ] }