Simple model of a battery with constant no-load voltage and inner resistance. Additionally, the current is integrated to obtain charge (and state of charge) of the battery, and the power is integrated to show the exchanged amount of energy.
OCV is specified with respect to nominal OCV = VDC.
Dependency of OCV (open circuit voltage) versus SOC (state of charge) is either defined by a linear dependency [SoCmin, VDCmin/VDC; 1,1]
or as a table on file with first column = SOC in the range [SoCmin, 1] and second column = OCV in the range [VDCmin/VDC, 1].