PURPOSE: A charging device of a lithium ion battery is provided to prevent the explosion generated due to the overcharge by stopping the charging if voltages of both ends of the battery exceed a predetermined voltage. CONSTITUTION: A current controlling section(14) maintains the current supplied to a battery by bifurcating the current at the front end of a shunt resistance between a charging power source supplying section and the battery. A voltage controlling section(16) controls a current controlling device connected between a charging power source supplying section and the battery. A charging safety section(23) outputs an error signal if a detected voltage is larger than a reference voltage. A battery protecting section(20) interrupts the battery and the charging power source supplying section by an error signal outputted at the charging safety section. A central controlling section(17) outputs an error display signal if the current and the voltage detected at a current and voltage detecting section differ from predetermined current and voltage and the temperature detected at a temperature detecting section(12) exceeds a predetermined temperature. A display section(21) displays the error display signal.
