The procedure is to perform current or voltage pulses of size i cell or ∆V in our HPPC analysis with alternating pulses and rest states (Algorithm 1). Knowledge of the open circuit voltage curve OCV(c 0 ) is necessary for this design structure, which may be difficult to validate once degradation occurs in a full cell. To ensure closeness to the true open circuit voltage curve, we perform voltage holds in between states of charge to ensure minimal influence of kinetics . The rest and pulse times can vary with different battery material and design.