The Battery Charging Hub for Phantom 3 Quadcopter from DJI allows you to sequentially charge up to four batteries. By connecting to the quadcopter's charger and power cord, the hub automatically begins charging the battery with the highest charge first, then moves on to the next most charged battery, and continues the process for all batteries. Each battery's status is monitored and displayed via LED indicators, giving you a clear view of the charging progress. This convenient hub streamlines the process of keeping your batteries charged and ready for flight.