Battery Charge/Discharge: Voltage vs State-of-Charge (2D)

This is the 2D-native counterpart to the 3D lithium-ion battery cutaway simulator. Rather than orbiting a rendered cell with animated ions and electrons, it draws the two curves that actually govern a charge/discharge cycle: a live schematic of the cell's fill level, current direction and voltage readout, and a rolling voltage-vs-time chart tracing both the open-circuit voltage (OCV) — the classic Li-ion curve with steep knees near empty and full and a broad plateau in between — and the terminal voltage you'd actually measure once the internal-resistance drop from C-rate, capacity and resistance sliders is subtracted or added. Push the C-rate or resistance up and watch the terminal-voltage line pull away from the OCV line, sometimes far enough to trip the cell's voltage cutoff before it's actually empty or full — the same electrochemistry as the 3D version, just plotted instead of rendered.