A secondary battery management system comprising: a secondary battery unit (200A to 200C) comprising a secondary battery; and a secondary battery management device, which is communicably connected to the secondary battery unit (200A to 200C), which manages the secondary battery unit (200A to 200C), and which is external to the secondary battery unit (200A to 200C), wherein the secondary battery unit (200A to 200C) further comprises: a measurer configured to measure an electric current value of the secondary battery; an electric current value integrator configured to integrate electric current values measured by the measurer and calculate an integrated value of the electric current values for a predetermined period; and a remaining capacity calculator configured to calculate a remaining capacity of the secondary battery on the basis of the integrated value calculated by the electric current value integrator, wherein the secondary battery management device is configured to: request the secondary battery unit (200A to 200C) to transmit a voltage and the remaining capacity of the secondary battery; receive the voltage and the remaining capacity of the secondary battery transmitted from the secondary battery unit (200A to 200C); calculate a value of correction of the remaining capacity on the basis of the voltage and the remaining capacity which have been received; and transmit the calculated value of correction to the secondary battery unit (200A to 200C), and wherein the remaining capacity calculator is configured to correct the remaining capacity of the secondary battery on the basis of the value of correction transmitted from the secondary battery management device. a secondary battery unit (200A to 200C) comprising a secondary battery; and a secondary battery management device, which is communicably connected to the secondary battery unit (200A to 200C), which manages the secondary battery unit (200A to 200C), and which is external to the secondary battery unit (200A to 200C), wherein the secondary battery unit (200A to 200C) further comprises: a measurer configured to measure an electric current value of the secondary battery; an electric current value integrator configured to integrate electric current values measured by the measurer and calculate an integrated value of the electric current values for a predetermined period; and a remaining capacity calculator configured to calculate a remaining capacity of the secondary battery on the basis of the integrated value calculated by the electric current value integrator, a measurer configured to measure an electric current value of the secondary battery; an electric current value integrator configured to integrate electric current values measured by the measurer and calculate an integrated value of the electric current values for a predetermined period; and a remaining capacity calculator configured to calculate a remaining capacity of the secondary battery on the basis of the integrated value calculated by the electric current value integrator, wherein the secondary battery management device is configured to: request the secondary battery unit (200A to 200C) to transmit a voltage and the remaining capacity of the secondary battery; receive the voltage and the remaining capacity of the secondary battery transmitted from the secondary battery unit (200A to 200C); calculate a value of correction of the remaining capacity on the basis of the voltage and the remaining capacity which have been received; and transmit the calculated value of correction to the secondary battery unit (200A to 200C), and request the secondary battery unit (200A to 200C) to transmit a voltage and the remaining capacity of the secondary battery; receive the voltage and the remaining capacity of the secondary battery transmitted from the secondary battery unit (200A to 200C); calculate a value of correction of the remaining capacity on the basis of the voltage and the remaining capacity which have been received; and transmit the calculated value of correction to the secondary battery unit (200A to 200C), and wherein the remaining capacity calculator is configured to correct the remaining capacity of the secondary battery on the basis of the value of correction transmitted from the secondary battery management device.