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Additional checks are listed below.", "observe": "Inspect the outputs and numerical checks on the block reference page.", "limits": "This endpoint-normalized index is not the same quantity as capacity retention. The endpoint choice determines its interpretation. The example verifies numerical behavior for synthetic parameters. Cell characterization and validation for an intended use are separate tasks.", "url": "https://design.lemonergy.com/cosim.html?example=block-battery-capacity-health", "label": "Open Studio example", "evidence": [ "docs/glossary/native-block-verification.json" ] } }, { "id": "workflow:native-battery-resistance-health", "type": "Workflow", "label": "Resistance health index worked example", "properties": { "id": "native-battery-resistance-health", "title": "Resistance health index worked example", "kind": "studio", "summary": "Endpoint-normalized health index with raw value and out-of-reference flag.", "steps": [ "Review the block inputs, units and model limits.", "Open the Studio example and run its bundled model.", "Compare the output channels with the numerical checks; change one input and run again." ], "example": "Use the defaults below with Measured resistance (ohm) = 0.075 1. At 0 s, Clipped health index is 0.5 1 (fraction). Additional checks are listed below.", "observe": "Inspect the outputs and numerical checks on the block reference page.", "limits": "This endpoint-normalized index is not the same quantity as capacity retention. The endpoint choice determines its interpretation. The example verifies numerical behavior for synthetic parameters. 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Additional checks are listed below.", "observe": "Inspect the outputs and numerical checks on the block reference page.", "limits": "SOC and integrated charge must describe the same windows. Biased SOC or current measurements bias the fit; this operation does not collect or qualify those measurements. The example verifies numerical behavior for synthetic parameters. 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At 0 s, Fitted capacity (Ah) is 2 Ah. Additional checks are listed below.", "observe": "Inspect the outputs and numerical checks on the block reference page.", "limits": "SOC and integrated charge must describe the same windows. Biased SOC or current measurements bias the fit; this operation does not collect or qualify those measurements. The example verifies numerical behavior for synthetic parameters. 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At 0 s, Estimated capacity (Ah) is 1.96 Ah. Additional checks are listed below.", "observe": "Inspect the outputs and numerical checks on the block reference page.", "limits": "Capacity is observable only with informative SOC changes. Feeding the same capacity-dependent SOC calculation back into the observer can create circular evidence. The example verifies numerical behavior for synthetic parameters. Cell characterization and validation for an intended use are separate tasks.", "url": "https://design.lemonergy.com/cosim.html?example=block-battery-capacity-observer", "label": "Open Studio example", "evidence": [ "docs/glossary/native-block-verification.json" ] } }, { "id": "workflow:native-battery-controlled-discharger", "type": "Workflow", "label": "Controlled discharger worked example", "properties": { "id": "native-battery-controlled-discharger", "title": "Controlled discharger worked example", "kind": "studio", "summary": "Triggered discharge request with low-voltage/time cutoff, recorded charge and latched completion.", "steps": [ "Review the block inputs, units and model limits.", "Open the Studio example and run its bundled model.", "Compare the output channels with the numerical checks; change one input and run again." ], "example": "Use the defaults below with Measured terminal voltage = 3.8 V, Measured discharge current = 1 A, Start trigger = 1 true / false, Enable = 1 true / false. At 0 s, Discharge-current request is 1 A. Additional checks are listed below.", "observe": "Inspect the outputs and numerical checks on the block reference page.", "limits": "The controller requests current; a separate plant or physical sink performs the discharge. The synthetic example is not a standardized cell test. The example verifies numerical behavior for synthetic parameters. Cell characterization and validation for an intended use are separate tasks.", "url": "https://design.lemonergy.com/cosim.html?example=block-battery-controlled-discharger", "label": "Open Studio example", "evidence": [ "docs/glossary/native-block-verification.json" ] } }, { "id": "topic:topic-ratings", "type": "Topic", "label": "Capacity, energy, power and ratings", "properties": { "id": "topic-ratings", "name": "Capacity, energy, power and ratings", "lede": "The numbers that size a cell and let two cells be compared.", "context": "Separate nameplate ratings from test results.", "example": "5 Ah at 3.6 V gives 18 Wh nominally. Integrated measured terminal power may give a different result.", "lesson_url": "https://lemonergy.com/learn/fundamentals/capacity-and-c-rate/", "lesson_label": "Open capacity and C-rate" } }, { "id": "term:ampere-hour", "type": "Term", "label": "Ampere-hour", "properties": { "id": "ampere-hour", "name": "Ampere-hour", "abbr": "Ah", "aka": [ "amp-hour" ], "section": "topic-units", "definition": "A unit of electric charge: one ampere flowing for one hour, or 3600 coulombs. Battery capacity is rated in ampere-hours, which measure charge, not energy.", "unit": "Ah", "related": [ "nominal-capacity", "milliampere-hour", "watt-hour" ], "lesson": "fundamentals/capacity-and-c-rate/#nominal-capacity", "url": "https://lemonergy.com/learn/glossary/ampere-hour/", "mentions": [ "ampere", "electric-charge" ] } }, { "id": "term:c-rate", "type": "Term", "label": "C-rate", "properties": { "id": "c-rate", "name": "C-rate", "section": "topic-ratings", "definition": "Current divided by nominal capacity, in reciprocal hours. 1C on a 20 Ah cell is 20 A; 2C is 40 A. C-rate lets you compare loads on cells of different sizes. The C here is not the coulomb, whose symbol is also C.", "formula": "C-rate = I / Q_nominal", "unit": "h⁻¹", "related": [ "nominal-capacity", "ideal-duration", "current", "e-rate", "fast-charging", "standard-charge-current" ], "lesson": "fundamentals/capacity-and-c-rate/#c-rate", "example": { "title": "Convert a rating into amperes", "text": "For a 5 Ah cell, 0.5C means 2.5 A, 1C means 5 A and 2C means 10 A. Dividing 2.5 A by 5 Ah returns 0.5 h⁻¹, conventionally written 0.5C." }, "url": "https://lemonergy.com/learn/glossary/c-rate/", "mentions": [ "coulomb" ] } }, { "id": "term:capacity-test", "type": "Term", "label": "Capacity test", "properties": { "id": "capacity-test", "name": "Capacity test", "section": "topic-testing", "definition": "A defined capacity test with specified charge, rest, discharge and cutoff conditions, usually a full CC-CV charge, a rest, and a C/3 or lower discharge to the lower cutoff at 25 °C. The delivered ampere-hours are the cell’s measured capacity.", "related": [ "nominal-capacity", "cc-cv-charging", "cutoff-voltage", "reference-performance-test", "rate-test" ], "lesson": "fundamentals/capacity-and-c-rate/#nominal-capacity", "url": "https://lemonergy.com/learn/glossary/capacity-test/", "mentions": [] } }, { "id": "term:usable-capacity", "type": "Term", "label": "Usable capacity", "properties": { "id": "usable-capacity", "name": "Usable capacity", "aka": [ "available capacity" ], "section": "topic-ratings", "definition": "The part of a cell’s capacity that a system actually lets it use, after the BMS reserves margins at the top and bottom of the state-of-charge window. An electric-car pack may use 90–95 % of its gross capacity.", "related": [ "nominal-capacity", "depth-of-discharge", "state-of-charge", "bms" ], "url": "https://lemonergy.com/learn/glossary/usable-capacity/", "mentions": [] } }, { "id": "term:state-of-health", "type": "Term", "label": "State of health", "properties": { "id": "state-of-health", "name": "State of health", "abbr": "SOH", "section": "topic-state", "definition": "A summary of how far a cell has aged, often expressed through remaining capacity or increased resistance compared with when it was new. By convention a cell has reached end of life at 80 % of its rated capacity.", "unit": "%", "related": [ "capacity-fade", "impedance-rise", "end-of-life", "remaining-useful-life", "state-of-charge", "state-of-certified-energy" ], "lesson": "fundamentals/capacity-and-c-rate/#real-cells", "url": "https://lemonergy.com/learn/glossary/state-of-health/", "mentions": [ "nominal-capacity" ] } }, { "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:capacity", "type": "Visual", "label": "C-rate, current and duration", "properties": { "title": "C-rate, current and duration", "summary": "A C-rate becomes an actual current only when capacity is known.", "readout": "5 Ah × 1C = 5 A. Ideal duration: 1 h (60 min).", "formula": "I = Q × C-rate; t_ideal = 1 / C-rate", "note": "Voltage cutoff, losses, temperature and rate-dependent capacity are excluded.", "software": { "status": "implemented", "label": "Implemented in battery-core", "body": "current_from_c_rate calculates I = Q × C-rate; ideal_duration_hours calculates 1 / C-rate. Neither predicts voltage-cutoff time or real usable capacity.", "href": "../fundamentals/capacity-and-c-rate/" }, "html": "
Ideal remaining charge
Ideal remaining chargeTime (h) versus Remaining charge (Ah). 1C. Interpretation follows the graphs.001.2512.523.75354Time (h)Remaining charge (Ah)
1C
" } }, { "id": "reference:inl-ev-tests", "type": "Reference", "label": "Battery Test Manual For Electric Vehicles, Revision 3", "properties": { "title": "Battery Test Manual For Electric Vehicles, Revision 3", "publisher": "Idaho National Laboratory", "url": "https://inldigitallibrary.inl.gov/sites/sti/sti/6492291.pdf", "type": "Test manual", "scope": "Performance characterization, pulse resistance/power, life testing and reference performance tests; historical 2015 edition.", "year": 2015, "authors": [ "Jon P. Christopherson" ], "accessed": "2026-10-27" } }, { "id": "reference:sandia-performance", "type": "Reference", "label": "DOE Energy Storage Handbook, Chapter 16: Energy Storage Performance Testing", "properties": { "title": "DOE Energy Storage Handbook, Chapter 16: Energy Storage Performance Testing", "publisher": "Sandia National Laboratories", "url": "https://www.sandia.gov/app/uploads/sites/163/2021/09/ESHB_Ch16_Testing_Rosewater.pdf", "type": "Technical handbook chapter", "scope": "Section 2.1.2.1 explains capacity, C-rate and the distinction between capacity and energy; also covers pulse characterization.", "accessed": "2026-10-27" } } ] }