{ "node": { "id": "term:series-parallel", "type": "Term", "label": "Series and parallel connection", "properties": { "id": "series-parallel", "name": "Series and parallel connection", "aka": [ "xSyP" ], "section": "topic-pack", "definition": "Cells in series add their voltages; cells in parallel add their capacities and share current. A pack is described as, for example, 96s4p: 96 groups in series, each of 4 cells in parallel. Series strings need balancing; parallel groups self-balance through their shared terminals.", "formula": "V = n_s·V_cell, Q = n_p·Q_cell", "related": [ "module", "cell-balancing", "pack-voltage", "volt", "fuse" ], "lesson": "fundamentals/battery-basics/#cell-module-pack", "example": { "title": "Assemble an ideal 4s2p pack", "text": "Eight identical 3.6 V, 5 Ah cells arranged as four series groups with two cells in parallel give 14.4 V nominal, 10 Ah and 144 Wh. Interconnect losses, cell variation and usable voltage limits are additional constraints." }, "url": "https://lemonergy.com/learn/glossary/series-parallel/", "mentions": [] } }, "edges": [ { "id": "edge:2817", "source": "term:series-parallel", "target": "topic:topic-pack", "type": "belongsTo", "properties": { "sourceFile": "terms.json" } }, { "id": "edge:2818", "source": "term:series-parallel", "target": "term:module", "type": "relatedTo", "properties": { "sourceFile": "terms.json", "meaning": "Related context; not a causal claim" } }, { "id": "edge:2819", "source": "term:series-parallel", "target": "term:cell-balancing", "type": "relatedTo", "properties": { "sourceFile": "terms.json", "meaning": "Related context; not a causal claim" } }, { "id": "edge:2820", "source": "term:series-parallel", "target": "term:pack-voltage", "type": "relatedTo", "properties": { "sourceFile": "terms.json", "meaning": "Related context; not a causal claim" } }, { "id": "edge:2821", "source": "term:series-parallel", "target": "term:volt", "type": "relatedTo", "properties": { "sourceFile": "terms.json", "meaning": "Related context; not a causal claim" } }, { "id": "edge:2822", "source": "term:series-parallel", "target": "term:fuse", "type": "relatedTo", "properties": { "sourceFile": "terms.json", "meaning": "Related context; not a causal claim" } }, { "id": "edge:2823", "source": "term:series-parallel", "target": "lesson:fundamentals/battery-basics/", "type": "explainedIn", "properties": { "sourceFile": "terms.json", "url": "https://lemonergy.com/learn/fundamentals/battery-basics/#cell-module-pack" } }, { "id": "edge:2824", "source": "term:series-parallel", "target": "visual:pack", "type": "illustratedBy", "properties": { "sourceFile": "visual-pages.json" } } ], "neighbors": [ { "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:module", "type": "Term", "label": "Module", "properties": { "id": "module", "name": "Module", "section": "topic-pack", "definition": "A group of cells connected in series and parallel, mechanically held together with its own voltage and temperature sensing, built as the unit from which a pack is assembled and serviced. Cell-to-pack designs do away with it.", "related": [ "cell", "pack", "series-parallel", "cell-to-pack", "cell-supervision-circuit" ], "lesson": "fundamentals/battery-basics/#cell-module-pack", "url": "https://lemonergy.com/learn/glossary/module/", "mentions": [] } }, { "id": "term:cell-balancing", "type": "Term", "label": "Cell balancing", "properties": { "id": "cell-balancing", "name": "Cell balancing", "section": "topic-state", "definition": "Equalising the state of charge of cells in series, since the pack is limited by its emptiest cell on discharge and its fullest on charge. Passive balancing bleeds charge from high cells through resistors; active balancing moves it between cells.", "related": [ "bms", "series-parallel", "state-of-charge", "cell-to-cell-variation" ], "example": { "title": "Pack average versus cell limits", "text": "Average pack SOC can look acceptable while one series cell reaches its voltage limit. One aggregate SOC state does not demonstrate cell balancing." }, "url": "https://lemonergy.com/learn/glossary/cell-balancing/", "mentions": [ "active-balancing" ] } }, { "id": "term:pack-voltage", "type": "Term", "label": "Pack voltage", "properties": { "id": "pack-voltage", "name": "Pack voltage", "aka": [ "400 V system", "800 V system" ], "section": "topic-pack", "definition": "The nominal voltage of the full series string, about 400 V in most electric cars and 800 V in newer ones. Doubling the voltage halves the current for the same power, so cables, connectors and losses shrink and charging can be faster.", "unit": "V", "related": [ "series-parallel", "dc-fast-charging", "high-voltage-interlock", "insulation-resistance" ], "url": "https://lemonergy.com/learn/glossary/pack-voltage/", "mentions": [ "nominal-voltage", "string" ] } }, { "id": "term:volt", "type": "Term", "label": "Volt", "properties": { "id": "volt", "name": "Volt", "abbr": "V", "section": "topic-units", "definition": "The SI unit of electric potential difference: one joule of energy per coulomb of charge. A lithium-ion cell sits around 3–4 V; packs reach hundreds of volts by putting cells in series.", "unit": "V", "related": [ "voltage", "nominal-voltage", "series-parallel" ], "url": "https://lemonergy.com/learn/glossary/volt/", "mentions": [ "coulomb", "joule" ] } }, { "id": "term:fuse", "type": "Term", "label": "Fuse", "properties": { "id": "fuse", "name": "Fuse", "section": "topic-hvsafety", "definition": "A link that melts and opens the circuit when current exceeds its rating. Packs use a main fuse in the high-voltage path and often a small fuse on each parallel cell connection, so one shorted cell does not drain its neighbours into the fault.", "related": [ "external-short-circuit", "pyrofuse", "battery-disconnect-unit", "series-parallel", "cell-level-fuse" ], "url": "https://lemonergy.com/learn/glossary/fuse/", "mentions": [] } }, { "id": "lesson:fundamentals/battery-basics/", "type": "Lesson", "label": "Lesson 0 · Battery basics", "properties": { "url": "https://lemonergy.com/learn/fundamentals/battery-basics/" } }, { "id": "visual:pack", "type": "Visual", "label": "Series voltage and parallel capacity", "properties": { "title": "Series voltage and parallel capacity", "summary": "Count series and parallel connections separately.", "readout": "4S2P: 8 cells, 14.8 V, 10 Ah, 148 Wh.", "formula": "V_pack = Ns V_cell; Q_pack = Np Q_cell", "note": "Identical 3.7 V, 5 Ah cells; ideal equal current sharing and no losses.", "software": { "status": "reference", "label": "Reference concept", "body": "Ideal pack ratings use V_pack = Ns V_cell and Q_pack = Np Q_cell. The core energy helper can multiply these ratings. Imbalance and current sharing require additional models.", "href": "../fundamentals/capacity-and-c-rate/" }, "html": "
Voltage along one series string
Voltage along one series stringSeries cells versus Voltage (V). 3.7 V per cell. Interpretation follows the graphs.0011.1322.2633.3944.412Series cellsVoltage (V)
3.7 V per cell
\n
Capacity from parallel cells
Capacity from parallel cellsParallel cells versus Capacity (Ah). 5 Ah per cell. Interpretation follows the graphs.007.51.515322.54.5306Parallel cellsCapacity (Ah)
5 Ah per cell
" } } ] }