This evaluation board from Analog Devices features reliable and uninterruptible power supply for vehicle tracking system. Link here (PDF)
A vehicle tracking system (VTS) is typically installed in cars and trucks. A VTS provides real-time information about the speed, location, and direction of the vehicle using technology, such as a global positioning system (GPS).
For a VTS to work reliably, it needs to have a robust dc-to-dc power supply. A power supply must be designed to protect the system from common automotive fault conditions like load dump, cold crank, reverse polarity, and other potential destructive transients described in the ISO 7637-2 and ISO 16750-2 standards.
In addition, in the absence of power coming from the vehicle, the system must be able to switch to the backup battery to ensure continuous operation. Ultimately, an automotive power supply must comply with automotive electromagnetic interference (EMI) standards, specifically CISPR 25.