BATTERY STATE ESTIMATION DEVICE, BATTERY CONTROL DEVICE, BATTERY SYSTEM, AND BATTERY STATE ESTIMATION METHOD

摘要

PROBLEM TO BE SOLVED: To estimate a state of charge of a battery with satisfactory accuracy in response to a change in charge characteristics due to a battery temperature, particularly, a change in charge characteristics at a low temperature.SOLUTION: A battery state estimation device according to the present invention performs weighted addition to a state of charge calculated based on a battery voltage and a state of charge calculated by integrating battery currents, and increases the proportion of the state of charge calculated by integrating the battery currents when a battery temperature is a predetermined temperature threshold value or below and the battery current is a predetermined current threshold value or less.