Fractional order model validation for the lead-acid battery resistance estimation: application to cranking capability

The electrical signals generated by a vehicle cranking offer an interesting way to estimate the lead-acid battery resistance. Since resistance and power are correlated, the cranking signals can thus be used to evaluate the battery cranking capability, and possibly to define a new battery SOF (State Of Function). This paper shows how a simple fractional model is suitable for simulating the battery dynamical behavior and especially for measuring its resistance in high-frequencies. The application of the model validation technique to fractional systems is then presented to provide a resistance estimation solution. Finally, a simpler method, meeting the automotive requirements, has been developed and validated with experimental data.