A control method for a lithium ion secondary battery includes performing a charging step of charging the lithium ion secondary battery with a predetermined quantity of electricity when the battery voltage of the lithium ion secondary battery has decreased to a lower limit battery voltage that is set at a value that falls within a range higher than (B−C) V and lower than or equal to (B−C+0.2) V where a maximum value of a positive electrode potential of a flat portion in a discharge positive electrode potential curve is B (V) and a negative electrode dissolution potential is C (V). It is possible to suppress a dissolution of a negative electrode current collector of the lithium ion secondary battery to prevent the service life of the lithium ion secondary battery from shortening because of an internal short circuit.