A battery managing apparatus includes a battery controller configured to determine a time when a battery enters a steady state based on a charge and discharge current of the battery that is measured in response to a switching of a charge and discharge circuit connected to the battery. The apparatus further includes a time controller configured to wake up the battery controller based on the time when the battery enters the steady state, the battery controller being controlled based on the switching of the charge and discharge circuit. The battery controller is configured to control the battery in response to the time controller waking up the battery controller.