a technique for controlling the state of a power supply in a mobile asset such as a cargo trailer . the technique detects motion status such as may be provided by a vibration sensor . the motion status signal is filtered by other signals , such as with inputs from a global positioning system sensor , and is then further used to select a power consumption mode . the power consumption mode may be further controlled based on configuration information that may indicate that a vibration source such as a refrigeration unit is present on the trailer .