Charging method for battery set and battery management system using the same

A battery management system for charging a battery set with a plurality of battery cells, comprising:

• a controller;
• a balancing power source, electrically connected to the controller;
• and
• switch modules, connected to the battery cells, the controller and the balancing power source;
• wherein the controller, the balancing power source and the switch modules cooperate to perform a charging method comprising:
• performing a serial charging on the battery cells;
• determining whether one of the battery cells reaches a saturation voltage;
• and
• performing a uniform separate charging on the battery cells when one of the battery cells reaches the saturation voltage, wherein the uniform separate charging comprises:
• sorting the battery cells according to cell voltages of the battery cells;
• and
• sequentially and separately charging the sorted battery cells to a Nth segmented voltage in a Nth segmentation, wherein N is a positive integer from 1 to K, and K is a positive integer larger than 1;
• wherein the battery cell with a minimum cell voltage is firstly charged to the Nth segmented voltage in the Nth segmentation, then the battery cell with a sub minimum cell voltage is charged to the Nth segmented voltage in the Nth segmentation, and then, in this manner, the next battery cell with the cell voltage less than the Nth segmented voltage is charged to the Nth segmented voltage in the Nth segmentation.