A battery equalization system, comprising: a collection circuit , configured to collect parameter information of cells in a battery pack ; a controller , connected to the collection circuit ; a charging branch circuit, connected to a charging device and the battery pack , and configured to charge the battery pack ; and a first power supply branch circuit , connected to the charging device and the battery equalization system, and configured to supply power to the battery equalization system; wherein the charging branch circuit is connected to a high-voltage direct current output terminal of the charging device, and the first power supply branch circuit is connected to a low-voltage direct current output terminal of the charging device; and the battery equalization system comprises an equalization circuit , configured to perform equalization processing on the cells in the battery pack ; wherein the controller is connected to the equalization circuit , and configured to: when it is determined, according to the parameter information of the cells in the battery pack , that a cell in the battery pack needs enabling of equalization, control the equalization circuit to perform equalization processing on the cell that needs enabling of equalization; wherein when a state-of-charge of the battery pack is full and a cell in the battery pack needs enabling of equalization, the controller controls the charging branch circuit to disconnect, and controls the first power supply branch circuit to keep connected, so that the equalization circuit performs equalization processing on the cell that needs enabling of equalization; wherein the equalization processing on the cell that needs enabling of equalization is performed in a passive equalization manner by discharging the cell that needs enabling of equalization. a collection circuit , configured to collect parameter information of cells in a battery pack ; a controller , connected to the collection circuit ; a charging branch circuit, connected to a charging device and the battery pack , and configured to charge the battery pack ; and a first power supply branch circuit , connected to the charging device and the battery equalization system, and configured to supply power to the battery equalization system; wherein the charging branch circuit is connected to a high-voltage direct current output terminal of the charging device, and the first power supply branch circuit is connected to a low-voltage direct current output terminal of the charging device; and the battery equalization system comprises an equalization circuit , configured to perform equalization processing on the cells in the battery pack ; wherein the controller is connected to the equalization circuit , and configured to: when it is determined, according to the parameter information of the cells in the battery pack , that a cell in the battery pack needs enabling of equalization, control the equalization circuit to perform equalization processing on the cell that needs enabling of equalization; wherein when a state-of-charge of the battery pack is full and a cell in the battery pack needs enabling of equalization, the controller controls the charging branch circuit to disconnect, and controls the first power supply branch circuit to keep connected, so that the equalization circuit performs equalization processing on the cell that needs enabling of equalization; wherein the equalization processing on the cell that needs enabling of equalization is performed in a passive equalization manner by discharging the cell that needs enabling of equalization. <EOS>