Abstract: A method of activating a battery is applied to an electronic device having a controller that keeps counting system time to acquire a system date. The method includes: (1) acquiring data of the battery, including states, an activation number and a last activation date; (2) performing an activation process and setting the battery in an activation state when determining, based on the data, that the battery is in an inactivation state, the activation number is smaller than a predetermined activation number, and an interval between the last activation date and the system date is greater than a predetermined activation interval; (3) discharging the battery, and charging the battery when determining that a battery power level is less than a predetermined power level; and (4) setting the battery in the inactivation state after the activation process is finished. Therefore, a curing problem of the battery is overcome.