BUSBAR DIAGNOSIS DEVICE, BATTERY PACK, ENERGY STORAGE SYSTEM, AND BUSBAR DIAGNOSIS METHOD

A busbar diagnosis apparatus includes a plurality of voltage sensing pins, a battery monitoring circuit, a voltage sensing channel, a bypass unit and a control circuit to diagnose s busbar. A voltage of each of a plurality of battery cells of a first battery module and a plurality of battery cells of a second battery module is detected using a potential difference of every two adjacent voltage sensing pins, and the busbar is diagnosed based on a voltage history of each of the plurality of battery cells.