A battery residual value determination system comprising: a user device and a server connected with each other by a communication network, wherein the user device includes a user device control unit, a sensor, a user device output unit, and a user device input unit, and the server includes a server control unit and a server storage unit, said server control unit being configured to read and execute predetermined programs to function as a battery information reception unit, a first residual value determination unit, an attenuation function determination unit, and a second residual value output unit, wherein said battery information reception unit is configured to receive information on a voltage, a current, a temperature, and a period of time elapsed from a time of manufacture of a battery for which a residual value is to be determined through the user device and is further configured to receive information indicating a service life thereof; said first residual value determination unit is configured to determine a current SOH (State of Health) of the battery based on the information on the voltage, the current, and the temperature of the battery received by the battery information reception unit and to determine the current SOH as a first residual value of the battery; said attenuation function determination unit is configured to determine an attenuation coefficient by using an attenuation function, said function being a function determined by the attenuation function determination unit on the basis of the information on the period of time elapsed from the time of manufacture of the battery and the information indicating the service life of the battery received by the battery information reception unit, said attenuation function indicating a time-dependent change of a SOH specific to the battery thereby to determine said attenuation coefficient used for correcting the first residual value of the battery; and said second residual value output unit is configured to determine and to output a second residual value which is obtained by correcting the first residual value by multiplying the first residual value by the attenuation coefficient and which indicates a corrected current SOH of the battery. a user device and a server connected with each other by a communication network, wherein the user device includes a user device control unit, a sensor, a user device output unit, and a user device input unit, and the server includes a server control unit and a server storage unit, said server control unit being configured to read and execute predetermined programs to function as a battery information reception unit, a first residual value determination unit, an attenuation function determination unit, and a second residual value output unit, wherein said battery information reception unit is configured to receive information on a voltage, a current, a temperature, and a period of time elapsed from a time of manufacture of a battery for which a residual value is to be determined through the user device and is further configured to receive information indicating a service life thereof; said first residual value determination unit is configured to determine a current SOH (State of Health) of the battery based on the information on the voltage, the current, and the temperature of the battery received by the battery information reception unit and to determine the current SOH as a first residual value of the battery; said attenuation function determination unit is configured to determine an attenuation coefficient by using an attenuation function, said function being a function determined by the attenuation function determination unit on the basis of the information on the period of time elapsed from the time of manufacture of the battery and the information indicating the service life of the battery received by the battery information reception unit, said attenuation function indicating a time-dependent change of a SOH specific to the battery thereby to determine said attenuation coefficient used for correcting the first residual value of the battery; and said second residual value output unit is configured to determine and to output a second residual value which is obtained by correcting the first residual value by multiplying the first residual value by the attenuation coefficient and which indicates a corrected current SOH of the battery.