1. Series/Parallel Relationships: $V_{\text{pack}} = S \cdot V_{\text{cell}}, \quad C_{\text{pack}} = P \cdot C_{\text{cell}}, \quad E_{\text{pack}} = V_{\text{pack}} \cdot C_{\text{pack}}$

2. Internal Resistance: $R_{\text{pack}} = \frac{S}{P} \cdot R_{\text{cell}}, \quad P_{\text{loss}} = I_{\text{load}}^2 \cdot R_{\text{pack}}$

3. Safe C-Rate Sizing: $I_{\text{cell}} = \frac{I_{\text{load}}}{P} \le C_{\text{max}} \cdot C_{\text{cell}}$