Lithium ion cell multi-module capacity detection device and method

The invention relates to a capacity detection device and method for a lithium ion battery cell multi-module. The capacity detection device comprises an upper computer control system, a battery management system, charging and discharging equipment, a battery pack and a battery module, the upper computer control system is connected with the battery management system through a communication line, the battery management system is connected with the battery pack through a sampling line tool, the battery management system is connected with the charging and discharging device through a sampling line tool, and the battery pack is connected with the charging and discharging device through a high-voltage cable. And the battery modules are connected in series through a high-voltage cable to form a battery pack. According to the invention, through high-voltage series connection of a plurality of modules in the same set of system, data is transmitted to the battery management system through the sampling line on each batte