BATTERY CHARGING APPARATUS CAPABLE OF MAINTAINING FULL CHARGE STATE OF BATTERY BY SWITCHING TO SUSTAIN CHARGE MODE WHEN VOLTAGE LEVEL OF BATTERY IS HIGHER THAN PREDETERMINED LEVEL

摘要

PURPOSE: A battery charging apparatus is provided to perform a quick charging operation in an early stage of battery charging operation and switch to a sustain charge mode when the voltage level of the battery is higher than a predetermined level. CONSTITUTION: A battery charging apparatus comprises a charger circuit(22), a first resistance, a second resistance, a current control switch(23), a battery(26), and a terminal modem(24). The charger circuit receives DC power from an AC/DC adaptor(21), and allows for constant flow of current based on a reference voltage. The first resistance limits the current of a sustain charging operation by the reference voltage. The second resistance is connected in parallel to the first resistance, and limits the current of a quick charging operation by the reference voltage. The current control switch cuts off the current of the quick charging operation by turning off the second resistance during sustain charging operation. The battery is charged with the current limited by the first resistance and the second resistance. The terminal modem senses the voltage level of the battery, and turns off the current control switch when the sensed voltage level is higher than a predetermined level.