A storage battery equalization device is provided with: a battery pack including a plurality of storage battery modules; a plurality of equalization circuits corresponding to the respective storage battery modules, each including a DC/AC mutual converter circuit, a variable capacitor, and a transformer; external wirings interconnecting secondary windings of the transformers; voltage monitors each being connected across both electrodes of a corresponding storage battery module; and an equalization control unit. The equalization control unit determines equalization groups, each including one or more storage battery modules for discharging and one or more storage battery modules for charging, sets one of electrostatic capacitance values to the variable capacitors for each equalization group, the electrostatic capacitances corresponding to resonance frequencies of the equalization circuits, and controls a frequency of an alternating current outputted from the DC/AC mutual converter circuit of each equalization circuit, to be the resonance frequency of the equalization circuit.