A power managing method, applied to an electronic system comprising a power providing device and one or more system modules (SM_1, SM_2, SM_n), the power providing device comprising at least one battery, the method comprising: (a) determining a total power budget of the power providing device; (b) obtaining system information of the electronic system; (c) determining an available power budget according to the total power budget and the system information; and (d) allocating the available power budget to the one or more system modules (SM_1, SM_2, SM_n) according to the system information; wherein the system information comprises real-time system operating information about one or more respective real-time operation requests of the one or more system modules (SM_1, SM_2, SM_n), and the step (d) comprises allocating the available power budget to the one or more system modules (SM_1, SM_2, SM_n) according to the real-time system request information; characterized in that allocating the available power budget to the one or more system modules (SM_1, SM_2, SM_n) according to the real-time system request information is performed by: generating a respective power budget for each of the one or more system modules (SM_1, SM_2, SM_n) or for each of one or more tasks associated with one or more requests generated by the one or more system modules (SM_1, SM_2, SM_n) by multiplying the available power budget by a ratio between the respective real-time operation request of the respective system module (SM_1, SM_2, SM_n), and a total system real-time operation requirement obtained by summing the one or more respective real-time operation requests of the one or more system modules (SM_1, SM_2, SM_n); wherein the system information comprises current leakage information indicating leakage for the one or more of the system modules (SM_1, SM_2, SM_n) that are currently activated and for the one or more of the system modules (SM_1, SM_2, SM_n) that are not currently activated, and the step (c) comprises determining the available power budget according to the total power budget and the current leakage information. (a) determining a total power budget of the power providing device; (b) obtaining system information of the electronic system; (c) determining an available power budget according to the total power budget and the system information; and (d) allocating the available power budget to the one or more system modules (SM_1, SM_2, SM_n) according to the system information; generating a respective power budget for each of the one or more system modules (SM_1, SM_2, SM_n) or for each of one or more tasks associated with one or more requests generated by the one or more system modules (SM_1, SM_2, SM_n) by multiplying the available power budget by a ratio between the respective real-time operation request of the respective system module (SM_1, SM_2, SM_n), and a total system real-time operation requirement obtained by summing the one or more respective real-time operation requests of the one or more system modules (SM_1, SM_2, SM_n); wherein the system information comprises current leakage information indicating leakage for the one or more of the system modules (SM_1, SM_2, SM_n) that are currently activated and for the one or more of the system modules (SM_1, SM_2, SM_n) that are not currently activated, and the step (c) comprises determining the available power budget according to the total power budget and the current leakage information.