Patent ID: 8659266

Claim:
An available charging/discharging current calculation method that estimates available maximum current values in charging/discharging operations of batteries based on at least one of battery current, voltage and temperature, the method comprising the steps of: calculating a resistance value based on an average current value and an average voltage obtained in a predetermined time period; dividing the calculated resistance value into a physical resistance component and a chemical resistance component; correcting the chemical resistance component based on the pulse discharging or charging operation time from the past to the present; acquiring voltage variation values in the history of the past charging/discharging operations; correcting the physical resistance component based on a detected battery temperature and a detected battery remaining capacity; estimating battery open-circuit voltages based on the physical and chemical resistance components, and a current, a voltage and the voltage variation values; obtaining corrected battery open-circuit voltages corresponding to a plurality of setting currents in order to predict the available maximum current values in a particular time; acquiring predicted reaching voltages corresponding to the plurality of setting currents based on said corrected physical resistance component, said corrected chemical resistance component and said corrected battery open-circuit voltages; and creating a battery current-voltage curve based on said setting currents and said predicted reaching voltages to acquire upper and lower limit voltages and upper and lower limit currents at a temperature whereby assigning the upper and lower limit currents to the available maximum current values in charging operation and discharging operation, respectively.