A charging system and method for charging a communication terminal are provided which supply to a battery a compensation current equivalent to an amount of current input to a communication terminal. The charging method includes detecting a value of current flowing to a communication terminal when a battery attached to the communication terminal is being charged by a charging device, outputting to the charging device a data signal corresponding to the detected current value, and adding a compensation current to the current input to the battery based on the detected current value. Regardless of an operation of the communication terminal, a constant current is supplied to the battery being charged, and thus, time taken for completing charging of the battery can be reduced.