BATTERY STATE ESTIMATING APPARATUS, BATTERY STATE ESTIMATING METHOD, NON-TRANSITORY COMPUTER READABLE MEDIUM, CONTROL CIRCUIT AND POWER STORAGE SYSTEM

A battery state estimating apparatus as an embodiment of the present invention includes a state estimator, a power estimator, and a determiner. The state estimator estimates a state of a battery. The power estimator estimates first power amount charged/discharged by the battery within a charging/discharging period, based on the state. The determiner compares the first power amount with second power amount inputted/outputted to/from the battery within the charging/discharging period and thereby determines validity of the state.