Method for Balancing Parallel Battery Packs Using Pre-Charging Circuit and Apparatus and System for the Same

Provided is a method in an electricity-driven apparatus to be driven by receiving power through a plurality of battery packs in a parallel type. The method includes detecting a state of charge (SOC) of each of the plurality of battery packs, calculating a voltage difference between the plurality of battery packs based on the detected SOC, and performing battery pack balancing based on the calculated voltage difference exceeding a threshold value. The battery pack balancing is performed by a pre-charging circuit including a balancing relay.