Since its introduction, consumer GPS has made the tracking of critical items in the transportation chain more popular. Shipment of items via rail car is one link in the chain that serves to benefit from GPS technology. This paper discusses a wireless communications system suitable for tracking rail cars. In particular, the power source selection and system testing are described. The system was limited to one device and one power source, a battery. Findings show that the lithium battery selected will power the device for one to three years, depending on transmission activity. Recommended areas of additional research include: battery recharging techniques, effects of connecting sensors to the device, and investigating other communications devices as they become available.