Patent ID: 8120328

Claim:
A charging system for charging a battery mounted on a portable terminal, comprising: a charging control unit that performs supply and control of a charging electric current and a charging voltage to said battery; a first temperature monitoring unit that monitors a device temperature inside said portable terminal; and a second temperature monitoring unit that monitors a battery temperature of said battery, wherein said charging control unit controls said charging electric current to be supplied to said battery according to said device temperature monitored by said first temperature monitoring unit and controls said charging voltage to be supplied to said battery according to said battery temperature monitored by said second temperature monitoring unit, the charging system further comprises: a temperature-corresponding electric current value storing unit that stores electric current values in correspondence with a plurality of set temperatures of said device temperature, wherein said charging control unit obtains, from said temperature-corresponding electric current value storing unit, an electric current value corresponding to said device temperature monitored by said first temperature monitoring unit, so as to control said charging electric current to be supplied to said battery; and a timer that monitors lapse of a predetermined period of time, wherein said temperature-corresponding electric current value storing unit stores said plurality of set temperatures of said device temperature including a first set temperature and a second set temperature lower than said first set temperature, and a first electric current value and a second electric current value respectively corresponding to said first set temperature and said second set temperature and the second electric current value being higher than the first electric current value, said first temperature monitoring unit monitors said device temperature each time said predetermined period of time monitored by said timer passes, and said charging control unit: makes access to said temperature-corresponding electric current value storing unit, supplies to said battery a charging electric current of said second electric current value for each cycle of lapse of said predetermined period of time of said timer when said device temperature is lower than or equal to said second set temperature, supplies to said battery a charging electric current of said first electric current value for every other cycle of lapse of said predetermined period of time of said timer when said device temperature is lower than said first set temperature and higher than said second set temperature, and stops supply of said charging electric current when said device temperature is higher than or equal to said first set temperature.