In almost all cases, if both a GPS and a VHF transmitter are part of the device, it will have a separate battery to power each of the devices. When working with wildlife, there is nothing more frustrating than coming back from the field having been unsuccessful in getting a GPS data download or receiving the VHF signal.

Batteries are extremely reliable but in the event either or the other system fails prematurely, it is nice to have access to the other system. By not powering the different systems using the same battery, we can minimize the risk of the worst case scenario for wildlife biologists in the field.