A control system of a vehicle includes: an engine; a plurality of accessories including an air conditioner; a battery; a generator; and an ECU configured to automatically stop the engine, control the generator to charge or discharge the battery, inhibit the engine from being automatically stopped, calculate a first stop time as a length of time for which the engine can be automatically stopped, during operation of the air conditioner, calculate a first electric quantity as an estimated quantity of electricity consumed, calculate a second stop time as a length of time for which the vehicle is predicted to be stopped in the future, calculate a second electric quantity as an estimated quantity of electricity consumed, and determine the SOC target value, based on the first electric quantity and the second electric quantity.