This simulator builds a reconfigurable pack from generic 3 Ah NMC-style teaching cells. Reconfigure the terminal links between series and parallel arrangements and compare how pack voltage, ampere-hour capacity, per-cell current sharing and equivalent pack resistance change as you vary the series count (Ns) and parallel string count (Np).
• A real-time 3D pack that rebuilds its cell geometry live as you change series and parallel counts — cell module, welded busbars and terminal joints, an insulating cell carrier, positive/negative pack terminals and a pack electronic load — with home view, focus-selected-part, full-enclosure toggle, exploded view, auto-rotate, expand and label controls. • Experiment controls for initial SOC (new trial), pack current from −6 A charge to +12 A discharge, ambient temperature, cells in series (Ns, 1–6) and parallel strings (Np, 1–4). • Live readouts for pack voltage, pack capacity (Ah), pack current, cell C-rate, pack resistance and cell SOC, plus an operating-sequence readout, switch-state panel and cell-readings table. • Playback controls: pause/resume, advance 1 s or 60 s, and a speed selector from real time up to 1 hour per second. • An Analysis tab with two charts and the pack equations (Vpack = Ns·Vcell, Qpack = Np·Qcell, Icell = Ipack/Np, Rpack = Ns·Rcell/Np) plus snapshot measurements. • A Test & diagnose tab with four guided experiments (4-series/1-string, 4s2p, comparing 4s2p against 2s4p at equal cell count, and a high-current 4s4p case), a model-verification bench, and a timestamped event log with report export. • A Learn & assess tab covering how series wiring adds voltage, how parallel wiring adds capacity, why total stored energy is set by cell count rather than arrangement, and the limits of the equal-sharing assumption, plus a two-question knowledge-check quiz and a written model-scope statement.
Wiring cells in series stacks their voltages while every cell in the string carries the same current — so an Ns-cell series string still has the ampere-hour capacity of a single cell, just at Ns times the voltage. Wiring strings in parallel instead divides the total pack current across the strings and adds their capacities together, while pack voltage stays at a single string's voltage. The simulator's 4s2p versus 2s4p experiment holds cell count fixed at eight and lets you see directly that the 2s4p pack has half the voltage and twice the ampere-hour capacity of the 4s2p pack — the two arrangements store the same total energy but deliver it at different voltage/current combinations.
The model assumes identical cells and symmetric interconnects, so current divides evenly among parallel strings and pack resistance follows Rpack = Ns·Rcell/Np exactly. Real packs with unequal cell SOC, aging or interconnect resistance do not automatically share current equally — a weaker or higher-resistance string can end up carrying disproportionate current, which is a common cause of imbalance in real packs. This is a teaching model: it excludes diffusion, aging, hysteresis, lithium plating and gas generation, and reconfiguring the pack in the simulator is a numerical fixture rather than a live wiring procedure.
No. Series wiring adds cell voltages together while every cell in the string carries the same current, so an all-series pack retains the single-cell ampere-hour capacity — only its voltage rises. Capacity only increases when you add parallel strings.
Both contain the same eight cells and store the same total energy, but the 4s2p pack (four in series, two strings in parallel) has roughly twice the voltage and half the ampere-hour capacity of the 2s4p pack (two in series, four strings in parallel). The simulator lets you compare both arrangements directly at the same initial SOC.
Per-cell current equals pack current divided by the number of parallel strings (Icell = Ipack/Np), and pack resistance equals Ns times single-cell resistance divided by Np (Rpack = Ns·Rcell/Np). These equations assume all cells are identical and share current equally.
The model assumes equal cells and equal current sharing within each parallel group, and reconfiguring series/parallel counts is a numerical fixture rather than a real wiring procedure. It excludes cell-to-cell mismatch effects, aging, diffusion, hysteresis, lithium plating and gas generation.