Balanced judgment and supplementary device of energy transfer type battery pack and method thereof

The invention relates to a balanced judgment and supplementary device of an energy transfer type battery pack and a method thereof, which are mainly used on occasions when numerous batteries are connected in series for use in industry. The device comprises balancing modules and a measurement and control module, wherein the balancing modules are connected in turns, are connected with each single battery, and charge the single battery by using the energy of the battery pack or the energy of an external power supply; the measurement and control module is connected with the battery pack and each single battery therein, and measures and compares the single battery. The method comprises the following steps of: measuring and controlling the total voltage of battery packs connected in series and the voltage of each single battery; calculating the average voltage of the batteries of the battery packs connected in series; sending starting/stopping signals; and making the voltage of the single battery approach to the average voltage of the battery packs. The device and the method have the advantages of having the function of ensuring the voltage balancing, which is performed in a mode of energy transfer, of the single batteries of the battery packs connected in series in use, having small losses, and being favorable to be applied to middle or large-capacity battery packs.