Vehicular power supply system

A vehicular power supply system including a sensor unit that detects a battery state of a storage battery that is capable of supplying electrical power to an electrical load, and a control unit that receives the battery state from the sensor unit via a communication path and performs instruction to perform energization and interruption of the energization between the storage battery and the electrical load based on the received battery state, wherein

• the sensor unit includes:
• a detection unit that detects the battery state of the storage battery;
• and
• a switch drive unit that performs drive control of a switch unit provided between the storage battery and the electrical load based on the instruction of the control unit to switch between the energization and the interruption of the energization between the storage battery and the electrical load,
• the control unit is configured to, in a normal state, output a notification signal indicating the normal state every time a certain time period has elapsed,
• if receiving the notification signal from the control unit every time the certain time period has elapsed, the switch drive unit maintains the energization between the storage battery and the electrical load, and if not receiving the notification signal from the control unit every time the certain time period has elapsed, the switch drive unit performs drive control of the switch unit to interrupt the energization between the storage battery and the electrical load after a predetermined allowable time has elapsed,
• the detection unit includes a first current detection unit that detects a first current value at a first point on an electrical path between the storage battery and the electrical load and a second current detection unit that detects a second current value at a second point different from the first point on the electrical path,
• if the first current value is a first threshold value or greater and the second current value is a second threshold value or greater, the switch drive unit performs drive control of the switch unit to interrupt the energization between the storage battery and the electrical load, and
• if the number of times the first current value is the first threshold value or more is a predetermined first number of times or more and if the number of times the second current value is the second threshold value or more is a second number of times, which is different from the first number of times, or more, the switch drive unit performs drive control of the switch unit to interrupt the energization between the storage battery and the electrical load.