A method of charging a battery includes performing a first charging operation in a first period, performing a second charging operation in a second period, and performing a third charging operation in a third period. Each of the first, second, and third periods includes a constant current supplying period and a constant voltage supplying period. Different currents are supplied in the constant current supplying periods of at least two of the first, second, and third periods. Different voltages are supplied in the constant voltage supplying periods of at least two of the first, second, and third periods. The second period is between the first and third periods, and the second period is longer than the first and third periods.