Method for balancing an energy storage system, wherein the energy storage system comprises a series circuit of storage modules (2,21), wherein the capacitive storage module has a capacitor, a double-layer capacitor or a lithium capacitor, wherein the series circuit of storage modules (2, 21) has at least two capacitive storage modules, wherein the capacitive storage modules are connected to a balancing device such that, by means of a flow of current between the balancing device and the capacitive storage modules, a charge of the capacitive storage modules can be influenced in each case, wherein the capacitive storage modules each have a capacitance (C i), wherein the method comprises the following steps: - ascertaining the capacitance (C i) of each of the capacitive storage modules, wherein in each case the capacitance (C i) of the individual capacitive storage modules is determined from the change in the voltage (U i) of the respective capacitive storage module and the current through the series circuit of the capacitive storage module, or is determined from the voltage (U i) of the respective capacitive storage module or from a current through a resistor, wherein the individual capacitive storage modules are each linked to a resistor, - determining a module charge (Q eq_i) for each of the capacitive storage modules at least from a voltage (U i) and the capacitance (C i) of the respective capacitive storage module and a predefinable balancing voltage (U eq_i), - determining a reference charge (Q ref) at least from the module charges (Q eq_i) of the capacitive storage modules, - determining a balancing charge (Q sym_i) for each of the capacitive storage modules at least from the reference charge (Q ref) and the module charge (Q eq_i) of the respective capacitive storage module and - influencing the charge of the capacitive storage modules by exchanging the respective balancing charge (Q sym_i) between the respective capacitive storage module and the balancing device. - ascertaining the capacitance (C i) of each of the capacitive storage modules, wherein in each case the capacitance (C i) of the individual capacitive storage modules is determined from the change in the voltage (U i) of the respective capacitive storage module and the current through the series circuit of the capacitive storage module, or is determined from the voltage (U i) of the respective capacitive storage module or from a current through a resistor, wherein the individual capacitive storage modules are each linked to a resistor, - determining a module charge (Q eq_i) for each of the capacitive storage modules at least from a voltage (U i) and the capacitance (C i) of the respective capacitive storage module and a predefinable balancing voltage (U eq_i), - determining a reference charge (Q ref) at least from the module charges (Q eq_i) of the capacitive storage modules, - determining a balancing charge (Q sym_i) for each of the capacitive storage modules at least from the reference charge (Q ref) and the module charge (Q eq_i) of the respective capacitive storage module and - influencing the charge of the capacitive storage modules by exchanging the respective balancing charge (Q sym_i) between the respective capacitive storage module and the balancing device.