A battery depletion prevention system for a vehicle includes a turn-off control apparatus, a power-supply monitoring apparatus, and a first switch. The power-supply monitoring apparatus is configured to monitor a value of a current flowing through a battery. The first switch is provided between the battery and an in-vehicle apparatus and not between the battery and a communication apparatus. The turn-off control apparatus is configured to determine, based on the detected value of the current whether current value abnormality is occurring. The turn-off control apparatus is configured to, upon determining that the current value abnormality is occurring, turn off the first switch and thereby achieve a first coupling state. The turn-off control apparatus is configured to, upon determining that the current value abnormality is no longer occurring in the first coupling state, perform abnormality notification to a user terminal of a user of the vehicle via the communication apparatus.