BATTERY PURE RESISTANCE MEASURING METHOD AND APPARATUS

摘要

[PROBLEMS] To provide a method and an apparatus for measuring the pure resistance of a battery during occurrence of a low-rate discharge. [MEANS FOR SOLVING PROBLEMS] The discharge current of a battery discharging at a low rate and the corresponding terminal voltage thereof are periodically actually measured. A first approximate expression representative of the terminal voltage corresponding to the discharge current in the increase direction and a second approximate expression representative of the terminal voltage corresponding to the discharge current in the decrease direction are obtained based on the actually measured discharge current and terminal voltage. The pure resistance existential range is restricted based on the first and second approximate expressions, and a point within the restricted existential range is regarded as a dummy pure resistance. A time point at which the dummy polarization corresponding to the dummy pure resistance is maximum is obtained from the second approximate expression and dummy pure resistance. Then, the true pure resistance is obtained based on two relational expressions representative of the relationships between the true pure resistance, the true maximum-polarization time point and the dummy maximum-polarization time point.