US Patent 7680479 Urgent message apparatus and system

An urgent message apparatus mounted in a vehicle, for transmitting, in an emergency, an urgent message with a backup battery with the use of a low-earth orbit orbiting satellite, detects a current position of the vehicle; a obtaining part obtaining a communication not-possible time zone of the low-earth orbit orbiting satellite, for the current position of the vehicle detected by the position detecting part; calculates a power amount to be consumed when the backup battery is maintained in a transmission standby state during the communication not-possible time zone obtained by the obtaining part; measures remaining power of the backup battery; compares a sum of a power amount required for transmitting the urgent message and the power amount calculated by the calculating part, with the remaining power measured by the measuring part; and determines that charging or replacement of the backup battery is required when the sum is larger.