ISG to be controlled by the structure of (Integrated Starter Generator) applies 42V conventional batteries and super capacitor is a simple two energy storage device voltage balance in a hybrid energy storage device that is applied is connected in parallel with the system in a hybrid electric vehicle for which relates to a voltage balancing device for a hybrid-type energy storage device, Integral with the starter and generator of ISG, if ISG to operate in the motor by controlling the respective phase voltages, and having a MCU to handle the generated voltage when operating the engine torque to the secondary, and the generator in accordance with the braking control to the constant voltage, different connecting a general battery with super capacitor has an energy storage characteristics in parallel and connecting the MCU and the super capacitor and, and all electric loads are connected to operate on the voltage of conventional batteries, are connected between the conventional batteries and super cap and the diode to maintain the voltage balance, is connected to the diode in parallel, when the voltage balance by the turn-on of the diode remains switched on under the control of the controller to continue to maintain the pressure equalization balance between super capacitor and the conventional battery and it characterized in that it comprises a switch. Super Cap, hives polycyclic energy storage devices, conventional batteries, ISG