{ "node": { "id": "term:calendar-life", "type": "Term", "label": "Calendar life", "properties": { "id": "calendar-life", "name": "Calendar life", "aka": [ "shelf life" ], "section": "topic-ratings", "definition": "How long a cell lasts in years, regardless of cycling, before it reaches its end-of-life criterion. It is set by calendar aging, which runs fastest at high temperature and high state of charge.", "unit": "years", "related": [ "calendar-aging", "cycle-life", "end-of-life", "self-discharge", "calendar-life-test" ], "url": "https://lemonergy.com/learn/glossary/calendar-life/", "mentions": [ "state-of-charge" ] } }, "edges": [ { "id": "edge:1014", "source": "term:calendar-life", "target": "topic:topic-ratings", "type": "belongsTo", "properties": { "sourceFile": "terms.json" } }, { "id": "edge:1015", "source": "term:calendar-life", "target": "term:calendar-aging", "type": "relatedTo", "properties": { "sourceFile": "terms.json", "meaning": "Related context; not a causal claim" } }, { "id": "edge:1016", "source": "term:calendar-life", "target": "term:cycle-life", "type": "relatedTo", "properties": { "sourceFile": "terms.json", "meaning": "Related context; not a causal claim" } }, { "id": "edge:1017", "source": "term:calendar-life", "target": "term:end-of-life", "type": "relatedTo", "properties": { "sourceFile": "terms.json", "meaning": "Related context; not a causal claim" } }, { "id": "edge:1018", "source": "term:calendar-life", "target": "term:self-discharge", "type": "relatedTo", "properties": { "sourceFile": "terms.json", "meaning": "Related context; not a causal claim" } }, { "id": "edge:1019", "source": "term:calendar-life", "target": "term:calendar-life-test", "type": "relatedTo", "properties": { "sourceFile": "terms.json", "meaning": "Related context; not a causal claim" } }, { "id": "edge:mentions/calendar-life/state-of-charge", "source": "term:calendar-life", "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:1021", "source": "term:calendar-life", "target": "visual:film", "type": "illustratedBy", "properties": { "sourceFile": "visual-pages.json" } } ], "neighbors": [ { "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:calendar-aging", "type": "Term", "label": "Calendar aging", "properties": { "id": "calendar-aging", "name": "Calendar aging", "section": "topic-aging", "definition": "Degradation that happens with time even when a cell is not cycled — in storage, for example. It is driven mainly by side reactions such as SEI growth and accelerates with temperature.", "related": [ "cycle-aging", "sei", "arrhenius", "square-root-of-time", "calendar-life" ], "lesson": "fundamentals/battery-aging/#whole-cell", "url": "https://lemonergy.com/learn/glossary/calendar-aging/", "mentions": [] } }, { "id": "term:cycle-life", "type": "Term", "label": "Cycle life", "properties": { "id": "cycle-life", "name": "Cycle life", "section": "topic-ratings", "definition": "The number of full charge–discharge cycles a cell completes before its capacity falls to a stated fraction, usually 80 %, of its initial value under defined conditions. LFP cells reach several thousand cycles; high-energy NMC fewer.", "unit": "cycles", "related": [ "end-of-life", "capacity-fade", "depth-of-discharge", "calendar-life", "equivalent-full-cycle", "cycle-life-test" ], "url": "https://lemonergy.com/learn/glossary/cycle-life/", "mentions": [] } }, { "id": "term:end-of-life", "type": "Term", "label": "End of life", "properties": { "id": "end-of-life", "name": "End of life", "abbr": "EOL", "section": "topic-state", "definition": "The point at which a cell no longer meets its application’s requirement, conventionally 80 % of initial capacity or a doubling of resistance. It is a definition for warranties and tests, not a point where the cell stops working.", "related": [ "state-of-health", "beginning-of-life", "cycle-life", "second-life", "knee-point" ], "url": "https://lemonergy.com/learn/glossary/end-of-life/", "mentions": [] } }, { "id": "term:self-discharge", "type": "Term", "label": "Self-discharge", "properties": { "id": "self-discharge", "name": "Self-discharge", "section": "topic-charging", "definition": "The slow loss of stored charge while a cell is not in use. An unexpected rise can signal a leakage path or a soft internal short.", "unit": "%/month", "related": [ "internal-short-circuit", "calendar-aging", "k-value", "calendar-life", "self-discharge-test" ], "lesson": "fundamentals/battery-aging/#check-yourself", "url": "https://lemonergy.com/learn/glossary/self-discharge/", "mentions": [] } }, { "id": "term:calendar-life-test", "type": "Term", "label": "Calendar-life test", "properties": { "id": "calendar-life-test", "name": "Calendar-life test", "aka": [ "storage test" ], "section": "topic-testing", "definition": "Storing cells at a matrix of temperatures and states of charge, typically 25–60 °C and 30–100 % SOC, with periodic reference tests, to fit the calendar-aging model. Months of data at high temperature are extrapolated to years at ambient through the Arrhenius law.", "related": [ "calendar-aging", "calendar-life", "arrhenius", "storage-soc", "accelerated-aging" ], "url": "https://lemonergy.com/learn/glossary/calendar-life-test/", "mentions": [ "state-of-charge" ] } }, { "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:film", "type": "Visual", "label": "Diffusion-limited film growth", "properties": { "title": "Diffusion-limited film growth", "summary": "Four times the elapsed time gives twice the film thickness in this model.", "readout": "At four reference time units, thickness is 2× the reference thickness.", "formula": "δ / δ_ref = √[(t / t_ref) A]", "note": "Normalized analytical relation, not a capacity-loss or SOH prediction.", "software": { "status": "implemented", "label": "Implemented in battery-core", "body": "parabolic_film_thickness uses reference thickness × √(relative time × acceleration). Converting film thickness to capacity loss requires a calibrated relationship.", "href": "../fundamentals/battery-aging/" }, "html": "
Relative film growth
Relative film growthTime / reference time versus Thickness / reference thickness. Selected acceleration; Reference conditions. Interpretation follows the graphs.002448612816Time / reference timeThickness / referencethickness
Selected accelerationReference conditions (dashed)
" } } ] }