{ "node": { "id": "term:battery-heating", "type": "Term", "label": "Battery heating", "properties": { "id": "battery-heating", "name": "Battery heating", "aka": [ "battery heater", "pulse heating", "AC heating", "internal heating", "self-heating cell" ], "section": "topic-thermal", "definition": "Warming a cold battery before charging or use. External methods use electric heaters, a heat pump or warm coolant; internal methods heat the cell through its own resistance with alternating current or rapid charge–discharge pulses. Experimental self-heating cells embed a nickel foil that takes them from −20 °C to 0 °C in about 20 seconds.", "related": [ "preconditioning", "heat-pump", "joule-heating", "lithium-plating", "operating-temperature", "thermal-management" ], "url": "https://lemonergy.com/learn/glossary/battery-heating/", "mentions": [] } }, "edges": [ { "id": "edge:115", "source": "term:battery-heating", "target": "workflow:charge-thermal", "type": "usedIn", "properties": { "sourceFile": "wiki-blocks.json" } }, { "id": "edge:4761", "source": "term:battery-heating", "target": "topic:topic-thermal", "type": "belongsTo", "properties": { "sourceFile": "terms.json" } }, { "id": "edge:4762", "source": "term:battery-heating", "target": "term:preconditioning", "type": "relatedTo", "properties": { "sourceFile": "terms.json", "meaning": "Related context; not a causal claim" } }, { "id": "edge:4763", "source": "term:battery-heating", "target": "term:heat-pump", "type": "relatedTo", "properties": { "sourceFile": "terms.json", "meaning": "Related context; not a causal claim" } }, { "id": "edge:4764", "source": "term:battery-heating", "target": "term:joule-heating", "type": "relatedTo", "properties": { "sourceFile": "terms.json", "meaning": "Related context; not a causal claim" } }, { "id": "edge:4765", "source": "term:battery-heating", "target": "term:lithium-plating", "type": "relatedTo", "properties": { "sourceFile": "terms.json", "meaning": "Related context; not a causal claim" } }, { "id": "edge:4766", "source": "term:battery-heating", "target": "term:operating-temperature", "type": "relatedTo", "properties": { "sourceFile": "terms.json", "meaning": "Related context; not a causal claim" } }, { "id": "edge:4767", "source": "term:battery-heating", "target": "term:thermal-management", "type": "relatedTo", "properties": { "sourceFile": "terms.json", "meaning": "Related context; not a causal claim" } }, { "id": "edge:4768", "source": "term:battery-heating", "target": "visual:thermal", "type": "illustratedBy", "properties": { "sourceFile": "visual-pages.json" } } ], "neighbors": [ { "id": "workflow:charge-thermal", "type": "Workflow", "label": "Inspect pack temperature", "properties": { "id": "charge-thermal", "title": "Inspect pack temperature", "kind": "protocol", "summary": "The separate Charge session can include a lumped thermal node.", "steps": [ "Provide thermal mass and conductance.", "Compare two ambient temperatures." ], "example": "100 kJ/K thermal mass and 100 W/K conductance give a 1000 s no-source temperature-difference time constant.", "observe": "Temperature limits can pause charge; heater and mass are separate.", "limits": "One node does not resolve gradients, coolant geometry or runaway. Studio’s native charger instead uses external temperature.", "url": "https://design.lemonergy.com/", "label": "Open Design → Charge session", "evidence": [ "js/charger.js" ] } }, { "id": "topic:topic-thermal", "type": "Topic", "label": "Thermal management and heat transfer", "properties": { "id": "topic-thermal", "name": "Thermal management and heat transfer", "lede": "How heat is made, moved and removed in cells and packs, and the hardware that keeps a battery at the right temperature.", "context": "Select spatial detail for the question.", "example": "Equal total heat in different layouts can produce different gradients. Average temperature can miss a hot spot.", "lesson_url": "https://lemonergy.com/learn/fundamentals/battery-aging/", "lesson_label": "Open temperature and aging" } }, { "id": "term:preconditioning", "type": "Term", "label": "Preconditioning", "properties": { "id": "preconditioning", "name": "Preconditioning", "section": "topic-thermal", "definition": "Warming or cooling the battery to its preferred temperature before a fast charge or a hard drive, using the vehicle’s own heaters and pumps. Navigating to a charger triggers it in many cars, because a cold pack cannot accept high current safely.", "related": [ "thermal-management", "fast-charging", "lithium-plating", "operating-temperature" ], "url": "https://lemonergy.com/learn/glossary/preconditioning/", "mentions": [ "charger" ] } }, { "id": "term:heat-pump", "type": "Term", "label": "Heat pump", "properties": { "id": "heat-pump", "name": "Heat pump", "aka": [ "coefficient of performance" ], "section": "topic-thermal", "definition": "A refrigerant circuit run to move heat from a colder place to a warmer one, delivering two to three units of heat per unit of electricity in mild winter conditions. In an electric vehicle it warms the cabin and battery from outside air and the waste heat of the motor and inverter, saving winter range compared with resistive heaters.", "related": [ "refrigerant-loop", "battery-heating", "preconditioning", "range", "chiller", "thermoelectric-cooling" ], "url": "https://lemonergy.com/learn/glossary/heat-pump/", "mentions": [ "inverter", "electric-vehicle" ] } }, { "id": "term:joule-heating", "type": "Term", "label": "Joule heating", "properties": { "id": "joule-heating", "name": "Joule heating", "aka": [ "ohmic heating", "resistive heating", "I²R loss" ], "section": "topic-thermal", "definition": "Heat produced by current flowing through a resistance, equal to the current squared times the resistance. Doubling the current quadruples it: a 1 mΩ cell gives 10 W at 100 A but 40 W at 200 A. It dominates heat generation at high C-rates and also warms busbars, welds and connectors.", "formula": "P = I²·R", "unit": "W", "related": [ "heat-generation", "internal-resistance", "busbar", "hot-spot", "ohms-law" ], "example": { "title": "See the squared-current penalty", "text": "A 10 mΩ resistance dissipates 1 W at 10 A and 4 W at 20 A. Doubling current quadruples resistive heat when resistance stays constant." }, "url": "https://lemonergy.com/learn/glossary/joule-heating/", "mentions": [] } }, { "id": "term:lithium-plating", "type": "Term", "label": "Lithium plating", "properties": { "id": "lithium-plating", "name": "Lithium plating", "section": "topic-aging", "definition": "Lithium metal depositing on the negative-electrode surface instead of intercalating into it. It is promoted by charging at low temperature or high current.", "related": [ "dendrite", "fast-charging", "intercalation", "np-ratio", "dead-lithium", "electrodeposition" ], "lesson": "fundamentals/battery-aging/#plating", "url": "https://lemonergy.com/learn/glossary/lithium-plating/", "mentions": [] } }, { "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:thermal-management", "type": "Term", "label": "Thermal management", "properties": { "id": "thermal-management", "name": "Thermal management", "abbr": "TMS", "aka": [ "battery thermal management system", "BTMS" ], "section": "topic-thermal", "definition": "Keeping cells in their comfortable range, roughly 15–35 °C, and within a few degrees of each other: liquid cooling plates, refrigerant plates or immersion for heat removal, and heaters or waste heat for warming before fast charging in the cold.", "related": [ "cooling-plate", "thermal-interface-material", "operating-temperature", "heat-generation", "preconditioning", "temperature-sensor" ], "url": "https://lemonergy.com/learn/glossary/thermal-management/", "mentions": [ "fast-charging" ] } }, { "id": "visual:thermal", "type": "Visual", "label": "Heat approaches an equilibrium", "properties": { "title": "Heat approaches an equilibrium", "summary": "Thermal resistance sets the steady temperature rise; thermal mass sets the response time.", "readout": "Steady rise: 10 K. Time constant: 8.333 min.", "formula": "ΔT = P R_th [1 − exp(−t / (C_th R_th))]", "note": "C_th = 500 J/K, fixed ambient and heat input, uniform temperature.", "software": { "status": "reference", "label": "Reference concept", "body": "Analysis → Charge session supports optional lumped thermal behavior. This independent explanation uses a 500 J/K thermal mass and constant heat input; it is not an application simulation result.", "href": "https://design.lemonergy.com/" }, "html": "
Temperature above ambient
Temperature above ambientTime (min) versus Temperature rise (K). Lumped response. Interpretation follows the graphs.001515303045456060Time (min)Temperature rise (K)
Lumped response
" } } ] }