DEVICE FOR MEASURING VOLTAGE AND INTERNAL RESISTANCE OF LITHIUM ION BATTERY

摘要

PURPOSE: A device for measuring voltage and internal resistance of a lithium ion battery is provided to carry out the progress of grading by measuring the terminal voltage and the internal resistance of a battery after charging a lithium ion battery. CONSTITUTION: A device for measuring voltage and internal resistance of a lithium ion battery includes an oscillating portion(11), a constant current portion(12), a battery(13), an open battery voltage detecting portion(14), an alternating current amplifying portion(15), an effective value rectifying portion(16) and a central control portion(19). The oscillating portion(11) generates the signal of the alternating current sine wave. The constant current portion(12) limits the amplitude of the sine wave of the oscillating portion(11) with the regular level and supplies it to the battery.(13). The open battery voltage detecting portion(14) detects the open battery voltage of the battery(13). The alternating current amplifying portion(15) amplifies the open battery voltage detected from the open battery voltage detecting portion(14). The effective value rectifying portion(16) outputs the effective value of the signal amplified from the alternating current amplifying portion(15). The central control portion(19) produces the internal resistance with the current of the constant current portion(12) and the effective value.