Electrical storage system, controller, and storage battery charging and discharging method

1. An electrical storage system, comprising: an electrical storage unit that includes one or two or more storage batteries; a storage unit that stores historical information of the electrical storage unit; and a control unit that acquires the historical information from the storage unit, and performs a control of changing a charging setting voltage value of the electrical storage unit to a low-charging voltage value lower than a typical-charging voltage value in a case where the charging setting voltage value of the electrical storage unit is set to the typical-charging voltage value and in a case where the historical information satisfies a voltage changing condition, and of returning the charging setting voltage value of the electrical storage unit to the typical-charging voltage value after the electrical storage unit performs charging and discharging with the low-charging voltage value, wherein the voltage changing condition is at least one of a condition in which the number of charging and discharging cycles, which are performed with the typical-charging voltage value, in the electrical storage unit is greater than a predetermined number of cycles, a condition in which out-of-temperature-range accumulated time, for which the electrical storage unit is used out of a typical-use temperature range, is greater than a threshold value, a condition in which internal resistance is greater than a predetermined value, a condition in which full-charging capacity is reduced from initial capacity by a predetermined value, and a condition of exceeding over passed accumulated time that is predicted by lifespan prediction; and a condition setting unit that sets a temperature T for calculation, a condition of a battery state S for calculation, and a condition of float charging, wherein the control unit performs calculation of a deterioration prediction value after (X+Y) days from initial charging from deterioration master data with respect to the electrical storage unit having a deterioration rate R at a point of time after passage of X days from the initial charging, the storage unit stores a plurality of pieces of the deterioration master data, the control unit specifies the deterioration master data by using conditions which are set by the condition setting unit, and in the deterioration master data that is specified, days of passage Xcorr, which applies the deterioration rate R, is derived, and the deterioration prediction value after (Xcorr+Y) days from the initial charging is obtained from the deterioration master data that is specified.

2. The electrical storage system according to claim 1 ,

wherein the control unit performs changing from the low-charging voltage value to the typical-charging voltage value after the electrical storage unit performs one cycle to five cycles of charging and discharging with the low-charging voltage value.

3. The electrical storage system according to claim 1 ,

wherein the predetermined number of cycles is 500 cycles to 1000 cycles.

4. The electrical storage system according to claim 1 ,

wherein the low-charging voltage value is a value that is lower than the typical voltage value by 0.1 V to 0.2 V.

5. The electrical storage system according to claim 1 ,

wherein in a case where the condition in which out-of-temperature-range accumulated time is greater than a threshold value is satisfied as the voltage changing condition,

the control unit performs changing to the typical-charging voltage value after the electrical storage unit is left in a typical-use temperature range.

6. The electrical storage system according to claim 1 , further comprising:

a display unit that displays the amount of charging of the electrical storage unit,

wherein in charging and discharging that is performed with the low-charging voltage value, display indicating full-charging is performed on the display unit when charging is completed.

7. The electrical storage system according to claim 1 ,

wherein in a case where the electrical storage unit includes two or more storage batteries,

the control is performed in a unit of storage battery.

8. The electrical storage system according to claim 1 ,

wherein in a case where the electrical storage unit includes a plurality of assembled batteries constituted by two or more storage batteries,

the control is performed in a unit of assembled battery.

9. The electrical storage system according to claim 1 ,

wherein the conditions in estimation for Y days include n conditions (Z 1 , Z 2 , . . . , Z n ) (1≤n), and

in transitioning from first deterioration master data that is specified by the condition Z n-1 into second deterioration master data that is specified by the condition Z n , the transitioning is performed so that a final deterioration rate in the first deterioration master data becomes an initiation deterioration rate in the second deterioration master data.

10. The electrical storage system according to claim 1 ,

wherein the storage battery is a lithium ion secondary battery that uses at least one of a lithium-transition metal phosphate compound having an olivine type structure, and a lithium-transition metal composite oxide having a layered rock salt structure as a positive electrode active material.

11. The electrical storage system according to claim 1 ,

wherein electric power is supplied from the electrical storage unit to a power network and/or a power generator, and the electric power is supplied from the power network and/or the power generator to the electrical storage unit.

12. A controller, comprising: a control unit that acquires the historical information of an electrical storage unit including one or two or more storage batteries, and performs a control of changing a charging setting voltage value of the electrical storage unit to a low-charging voltage value lower than a typical-charging voltage value in a case where the charging setting voltage value of the electrical storage unit is set to the typical-charging voltage value and in a case where the historical information satisfies a voltage changing condition, and of returning the charging setting voltage value of the electrical storage unit to the typical-charging voltage value after the electrical storage unit performs charging and discharging with the low-charging voltage value, wherein the voltage changing condition is at least one of a condition in which the number of charging and discharging cycles, which are performed with the typical-charging voltage value, in the electrical storage unit is greater than a predetermined number of cycles, a condition in which out-of-temperature-range accumulated time, for which the electrical storage unit is used out of a typical-use temperature range, is greater than a threshold value, a condition in which internal resistance is greater than a predetermined value, a condition in which full-charging capacity is reduced from initial capacity by a predetermined value, and a condition of exceeding over passed accumulated time that is predicted by lifespan prediction; and a condition setting unit that sets a temperature T for calculation, a condition of a battery state S for calculation, and a condition of float charging, wherein the control unit performs calculation of a deterioration prediction value after (X+Y) days from initial charging from deterioration master data with respect to the electrical storage unit having a deterioration rate R at a point of time after passage of X days from the initial charging, the storage unit stores a plurality of pieces of the deterioration master data, the control unit specifies the deterioration master data by using conditions which are set by the condition setting unit, and in the deterioration master data that is specified, days of passage Xcorr, which applies the deterioration rate R, is derived, and the deterioration prediction value after (Xcorr+Y) days from the initial charging is obtained from the deterioration master data that is specified.

13. A storage battery charging and discharging method, comprising: acquiring the historical information of an electrical storage unit including one or two or more storage batteries; and performing a control of changing a charging setting voltage value of the electrical storage unit to a low-charging voltage value lower than a typical-charging voltage value in a case where the charging setting voltage value of the electrical storage unit is set to the typical-charging voltage value and in a case where the historical information satisfies a voltage changing condition, and of returning the charging setting voltage value of the electrical storage unit to the typical-charging voltage value after the electrical storage unit performs charging and discharging with the low-charging voltage value, wherein the voltage changing condition is at least one of a condition in which the number of charging and discharging cycles, which are performed with the typical-charging voltage value, in the electrical storage unit is greater than a predetermined number of cycles, a condition in which out-of-temperature-range accumulated time, for which the electrical storage unit is used out of a typical-use temperature range, is greater than a threshold value, a condition in which internal resistance is greater than a predetermined value, a condition in which full-charging capacity is reduced from initial capacity by a predetermined value, and a condition of exceeding over passed accumulated time that is predicted by lifespan prediction; and a condition setting unit that sets a temperature T for calculation, a condition of a battery state S for calculation, and a condition of float charging, wherein the control unit performs calculation of a deterioration prediction value after (X+Y) days from initial charging from deterioration master data with respect to the electrical storage unit having a deterioration rate R at a point of time after passage of X days from the initial charging, the storage unit stores a plurality of pieces of the deterioration master data, the control unit specifies the deterioration master data by using conditions which are set by the condition setting unit, and in the deterioration master data that is specified, days of passage Xcorr, which applies the deterioration rate R, is derived, and the deterioration prediction value after (Xcorr+Y) days from the initial charging is obtained from the deterioration master data that is specified.