The invention discloses a battery connecting piece. The battery connecting piece comprises a PCB, a fuse, a first series part electrically connected with a first battery, a second series part electrically connected with a second battery, and a parallel part electrically connected with the first series part; the fuse, the first series part and the parallel part are arranged on the top surface of the PCB; the second series part is arranged on the bottom surface of the PCB; first penetration holes are formed in the PCB; the first series part is electrically connected with the first end of the fuse; and the second end of the fuse passes through the first penetration holes to be electrically connected with the second series part. By virtue of the structure, when the battery suffers from a fault, the electric connection relation of the battery is disconnected, and electrical connection of circumjacent batteries can be maintained through the parallel part, so that accident caused by series-parallel connection of the faulty batteries can be avoided, while influence of the faulty batteries to the performance of the power battery pack can be lowered, thereby improving stability of the powerbattery pack and ensuring personal safety of passengers. The invention also provides a battery and a battery array.