Method for operating an energy store comprising at least one energy storage module (EM m) which has a plurality of energy storage cells (EZ m,z) which are each electrically coupled to a monitoring unit which is designed to discharge the energy storage cell (EZ m,z) with a predefined symmetrical current (I S) in an active operating state, in which the method comprises the following steps: - detecting an open-circuit voltage (OCV m,z) of the respective energy storage cell (EZ m,z), - determining a discharge time duration (t_aktiv m,z) for the respective energy storage cell (EZ m,z) depending on - - the predefined symmetrical current (Is), - - the open-circuit voltage (OCV m,z) of the energy storage cell (EZ m,z), - - a predefined target discharge voltage value (U_global_min) for the energy store, - - a predefined gradient of an open-circuit voltage characteristic (OCV_SOC) of the energy storage cell (EZ m,z), wherein the open-circuit voltage characteristic (OCV_SOC) describes a profile of the open-circuit voltage (OCV m,z) of the energy storage cell (EZ m,z) depending on a state of charge of the energy storage cell (EZ m,z), - - an operating current (I SG) of the monitoring unit which said monitoring unit takes from the energy storage cell (EZ m,z) during a waking phase, and - - a maximum cell voltage (U_modul_max,m) for the respective energy storage module (EM m), wherein the maximum cell voltage (U_modul_max,m) is determined depending on the open-circuit voltages (OCV m,z) of the respective energy storage cells (EZ m,z) of the energy storage module (EM m), and - driving the respective monitoring unit to discharge the respective energy storage cell (EZ m,z) with the predefined symmetrical current (Is) for the discharge time duration (t_aktiv m,z) assigned to the respective energy storage cell (EZ m,z). - detecting an open-circuit voltage (OCV m,z) of the respective energy storage cell (EZ m,z), - determining a discharge time duration (t_aktiv m,z) for the respective energy storage cell (EZ m,z) depending on - - the predefined symmetrical current (Is), - - the open-circuit voltage (OCV m,z) of the energy storage cell (EZ m,z), - - a predefined target discharge voltage value (U_global_min) for the energy store, - - a predefined gradient of an open-circuit voltage characteristic (OCV_SOC) of the energy storage cell (EZ m,z), wherein the open-circuit voltage characteristic (OCV_SOC) describes a profile of the open-circuit voltage (OCV m,z) of the energy storage cell (EZ m,z) depending on a state of charge of the energy storage cell (EZ m,z), - - an operating current (I SG) of the monitoring unit which said monitoring unit takes from the energy storage cell (EZ m,z) during a waking phase, and - - a maximum cell voltage (U_modul_max,m) for the respective energy storage module (EM m), wherein the maximum cell voltage (U_modul_max,m) is determined depending on the open-circuit voltages (OCV m,z) of the respective energy storage cells (EZ m,z) of the energy storage module (EM m), and - - the predefined symmetrical current (Is), - - the open-circuit voltage (OCV m,z) of the energy storage cell (EZ m,z), - - a predefined target discharge voltage value (U_global_min) for the energy store, - - a predefined gradient of an open-circuit voltage characteristic (OCV_SOC) of the energy storage cell (EZ m,z), wherein the open-circuit voltage characteristic (OCV_SOC) describes a profile of the open-circuit voltage (OCV m,z) of the energy storage cell (EZ m,z) depending on a state of charge of the energy storage cell (EZ m,z), - - an operating current (I SG) of the monitoring unit which said monitoring unit takes from the energy storage cell (EZ m,z) during a waking phase, and - - a maximum cell voltage (U_modul_max,m) for the respective energy storage module (EM m), wherein the maximum cell voltage (U_modul_max,m) is determined depending on the open-circuit voltages (OCV m,z) of the respective energy storage cells (EZ m,z) of the energy storage module (EM m), and - driving the respective monitoring unit to discharge the respective energy storage cell (EZ m,z) with the predefined symmetrical current (Is) for the discharge time duration (t_aktiv m,z) assigned to the respective energy storage cell (EZ m,z).