Technical solutions are described for conserving battery consumption in tracking devices when tracking a plurality of shipment items. An example method includes receiving, by a first tracking device that is associated with a first shipment item, a tracking information of a second shipment item, the tracking information being transmitted by a second tracking device. The method also includes transmitting, by the first tracking device, a tracking message that includes the tracking information of the second shipment item and a tracking information of the first shipment item.