The battery open circuit voltage Uocv has the certain correspondence relationship with the battery SOC under certainconditions,whichisoftenusedtosetuptheinitial.
BATTERY EQUIVALENT CIRCUIT MODELS 2.1 Thevenin model The Thevenin model, shown in Fig. 1, is obtained by adding a parallel RC network to the Rint model in order to include the polarization effect and to better describe the charging/discharging and recovery periods.
Lead-acid batteries are fully charged if one can measure an open-circuit voltage of fully discharged battery cell (s). The term discharged means that all free charges within the battery are zero and the only voltage source is the cell (s) voltage, V 0 (Fuchs and Masoum, 2011).
The voltage of a typical single lead-acid cell is ∼ 2 V. As the battery discharges, lead sulfate (PbSO 4) is deposited on each electrode, reducing the area available for the reactions. Near the fully discharged state (see Figure 3), cell voltage drops, and internal resistance increases.
Electrochemical battery models (Doyle, Fuller, and Newman, 1993; Haran, Popov, and White, 1998) are based on partial differential equations accounting for the dynamics of particles inside the battery. Albeit highly accurate, these models are quite complex and require knowledge of a large number of parameters which are difficult to obtain.
A lead-acid battery cell consists of a positive electrode made of lead dioxide (PbO 2) and a negative electrode made of porous metallic lead (Pb), both of which are immersed in a sulfuric acid (H 2 SO 4) water solution. This solution forms an electrolyte with free (H+ and SO42-) ions. Chemical reactions take place at the electrodes:
Electrochemical battery models (Doyle, Fuller, and Newman, 1993; Haran, Popov, and White, 1998) are base on partial differential equations accounting for the dynamics of particles inside the battery. Albeit highly accur te, these mode s are quite complex and require knowledge of a larg number of parameters which are difficult to obtain.