A battery information processing system includes a storage device configured to store an equivalent circuit model which expresses an AC impedance of a battery module with a plurality of circuit constants. The plurality of circuit constants include first to eighth circuit constants. The first circuit constant is a junction inductance.
The second circuit constant is a junction resistance. The third circuit constant is a solution resistance and the fourth circuit constant is a charge transfer resistance. The fifth circuit constant is a CPE index of a diffusion resistance. The sixth circuit constant is a CPE constant of the diffusion resistance. The seventh circuit constant is a CPE index of an electric double layer capacitance. The eighth circuit constant is a CPE constant of the electric double layer capacitance.