A vehicle comprising: a chargeable and dischargeable secondary battery ( B1, B2); a current sensor ( 11-1, 11-2) for detecting electric current of said secondary battery (B1, B2); and a controller for estimating a state of charge of said secondary battery (B1, B2) and controlling charging and discharging of said secondary battery (B1, B2) based on said state of charge, characterized in that in a first operation mode in which a charging cycle and a discharging cycle are repeated, said controller estimating the state of charge of said secondary battery (B1, B2) by a first estimation method of estimating an open-circuit voltage of said secondary battery ( B1, B2) and determining said state of charge based on a value obtained by correcting said open-circuit voltage based on polarization, in a second operation mode in which one of charging and discharging is continued, said controller estimating the state of charge of said secondary battery (B1, B2) by a second estimation method different from said first estimation method, following said second estimation method, said controller determining said state of charge based on a result of integration of the electric current detected by said current sensor ( 11-1, 11-2), said vehicle being configured to be able to perform external charging by which said secondary battery (B1, B2) is charged from a source external to the vehicle, said vehicle further comprising an air conditioning apparatus capable of executing pre-ride air conditioning using electric power supplied from said secondary battery (B1, B2), said second operation mode being selected when said external charging is performed and when said pre-ride air conditioning is performed, and when one of said external charging and said pre-ride air conditioning is executed as a preprocess and the other of said external charging and said pre-ride air conditioning is executed as a post-process performed subsequently to said preprocess, said controller storing an offset value of said current sensor ( 11-1, 11-2) before said preprocess is executed and, when said post-process is executed, said controller using said offset value stored before said preprocess is executed, to correct the electric current detected by said current sensor ( 11-1, 11-2). a chargeable and dischargeable secondary battery ( B1, B2); a current sensor ( 11-1, 11-2) for detecting electric current of said secondary battery (B1, B2); and a controller for estimating a state of charge of said secondary battery (B1, B2) and controlling charging and discharging of said secondary battery (B1, B2) based on said state of charge, characterized in that in a first operation mode in which a charging cycle and a discharging cycle are repeated, said controller estimating the state of charge of said secondary battery (B1, B2) by a first estimation method of estimating an open-circuit voltage of said secondary battery ( B1, B2) and determining said state of charge based on a value obtained by correcting said open-circuit voltage based on polarization, in a second operation mode in which one of charging and discharging is continued, said controller estimating the state of charge of said secondary battery (B1, B2) by a second estimation method different from said first estimation method, following said second estimation method, said controller determining said state of charge based on a result of integration of the electric current detected by said current sensor ( 11-1, 11-2), said vehicle being configured to be able to perform external charging by which said secondary battery (B1, B2) is charged from a source external to the vehicle, said vehicle further comprising an air conditioning apparatus capable of executing pre-ride air conditioning using electric power supplied from said secondary battery (B1, B2), said second operation mode being selected when said external charging is performed and when said pre-ride air conditioning is performed, and when one of said external charging and said pre-ride air conditioning is executed as a preprocess and the other of said external charging and said pre-ride air conditioning is executed as a post-process performed subsequently to said preprocess, said controller storing an offset value of said current sensor ( 11-1, 11-2) before said preprocess is executed and, when said post-process is executed, said controller using said offset value stored before said preprocess is executed, to correct the electric current detected by said current sensor ( 11-1, 11-2).