Battery - Determination and Forecast via Synergetics

A rechargeable battery can be considered as a complex system which is self-organizing under charging, discharging and relaxation. Depending of the type of battery and the kind of external influences, the battery is stressed in many different ways. This leads to an alteration of the internal self-organization processes which are indicative for the present internal state and the future development of the battery. To get detailed information about the State-Of-Charge (SOC) and the State-Of-Health (SOH) of such electrochemical systems we carried out on the one hand internal spatio-temporal measurements of the half-cell potentials within lead-acid batteries. By this, significant structure formation can be observed and is represented using several methods of synergetics. On the other hand, we performed external short-time measurements of the battery's voltage with differently triggered charging and discharging currents. The response curves of repeated excitations are characteristic for the dynamic behavior of the electrochemical system providing information on the battery's aging state. The fits of these curves are comprehended in a small set of significant parameters.