A system comprising: a lithium ion secondary battery having a weight per unit area x [g/cm 2] of a negative electrode of the lithium ion secondary battery and a density y [g/cm 3] of the negative electrode, and a control apparatus comprising: a control unit configured to control a charging apparatus configured to perform charging of the lithium ion secondary battery, wherein the control unit is configured to perform: causing the charging apparatus to perform the charging of the lithium ion secondary battery, until a voltage of the lithium ion secondary battery becomes a predetermined voltage; causing the charging apparatus to suspend the charging of the lithium ion secondary battery, until a predetermined time t elapses, after the charging; and causing the charging apparatus to further perform the charging of the lithium ion secondary battery, after the suspending, and characterized in that the control apparatus is configured to set the predetermined time t [minute] by being configured to calculate the predetermined time t [minute] such that it satisfies a condition that is determined by Expression using the weight per unit area x [g/cm 2] of the negative electrode of the lithium ion secondary battery and the density y [g/cm 3] of the negative electrode, wherein Expression 1 is: t ≥ − A + B ∗ x + C ∗ y 50 ≤ A ≤ 70,500 ≤ B ≤ 620,30 ≤ C ≤ 36 with the unit of coefficient A being [minute], the unit of coefficient B being [minute/(g/cm 2)] and the unit of coefficient C being [minute/(g/cm 3)]. a lithium ion secondary battery having a weight per unit area x [g/cm 2] of a negative electrode of the lithium ion secondary battery and a density y [g/cm 3] of the negative electrode, and a control apparatus comprising: a control unit configured to control a charging apparatus configured to perform charging of the lithium ion secondary battery, wherein the control unit is configured to perform: causing the charging apparatus to perform the charging of the lithium ion secondary battery, until a voltage of the lithium ion secondary battery becomes a predetermined voltage; causing the charging apparatus to suspend the charging of the lithium ion secondary battery, until a predetermined time t elapses, after the charging; and causing the charging apparatus to further perform the charging of the lithium ion secondary battery, after the suspending, and characterized in that the control apparatus is configured to set the predetermined time t [minute] by being configured to calculate the predetermined time t [minute] such that it satisfies a condition that is determined by Expression using the weight per unit area x [g/cm 2] of the negative electrode of the lithium ion secondary battery and the density y [g/cm 3] of the negative electrode, wherein Expression 1 is: t ≥ − A + B ∗ x + C ∗ y 50 ≤ A ≤ 70,500 ≤ B ≤ 620,30 ≤ C ≤ 36 with the unit of coefficient A being [minute], the unit of coefficient B being [minute/(g/cm 2)] and the unit of coefficient C being [minute/(g/cm 3)]. a control unit configured to control a charging apparatus configured to perform charging of the lithium ion secondary battery, wherein the control unit is configured to perform: causing the charging apparatus to perform the charging of the lithium ion secondary battery, until a voltage of the lithium ion secondary battery becomes a predetermined voltage; causing the charging apparatus to suspend the charging of the lithium ion secondary battery, until a predetermined time t elapses, after the charging; and causing the charging apparatus to further perform the charging of the lithium ion secondary battery, after the suspending, and characterized in that the control apparatus is configured to set the predetermined time t [minute] by being configured to calculate the predetermined time t [minute] such that it satisfies a condition that is determined by Expression using the weight per unit area x [g/cm 2] of the negative electrode of the lithium ion secondary battery and the density y [g/cm 3] of the negative electrode, wherein Expression 1 is: t ≥ − A + B ∗ x + C ∗ y 50 ≤ A ≤ 70,500 ≤ B ≤ 620,30 ≤ C ≤ 36 with the unit of coefficient A being [minute], the unit of coefficient B being [minute/(g/cm 2)] and the unit of coefficient C being [minute/(g/cm 3)]. causing the charging apparatus to perform the charging of the lithium ion secondary battery, until a voltage of the lithium ion secondary battery becomes a predetermined voltage; causing the charging apparatus to suspend the charging of the lithium ion secondary battery, until a predetermined time t elapses, after the charging; and causing the charging apparatus to further perform the charging of the lithium ion secondary battery, after the suspending, and characterized in that the control apparatus is configured to set the predetermined time t [minute] by being configured to calculate the predetermined time t [minute] such that it satisfies a condition that is determined by Expression using the weight per unit area x [g/cm 2] of the negative electrode of the lithium ion secondary battery and the density y [g/cm 3] of the negative electrode, wherein Expression 1 is: t ≥ − A + B ∗ x + C ∗ y 50 ≤ A ≤ 70,500 ≤ B ≤ 620,30 ≤ C ≤ 36 with the unit of coefficient A being [minute], the unit of coefficient B being [minute/(g/cm 2)] and the unit of coefficient C being [minute/(g/cm 3)].