Patent ID: 9337654
Filing Date: 2016-05-10
CPC Classification: H01M,H02J,Y02E

Claim Text:
1. A power storage device, comprising: a grid; a plurality of operation units, each including a sodium-sulfur battery, a parallel-in/off mechanism and a power consuming body, said parallel-in/off mechanism switching between a state where said sodium-sulfur battery is paralleled in to said grid and a state where said sodium-sulfur battery is paralleled off from said grid, said power consuming body being electrically connected to said grid; a shutoff detecting mechanism that detects a power reception shutoff; a remaining capacity specifying section that specifies an index of a remaining capacity of said sodium-sulfur battery belonging to each of said plurality of operation units; a rank giving section that refers to the index of the remaining capacity specified by said remaining capacity specifying section, to give rank to each of said plurality of operation units, the rank becoming higher as the remaining capacity of said sodium-sulfur battery belonging to each of said plurality of operation units becoming greater; a selecting section that selects a first operation unit given a highest rank by said rank giving section, when said shutoff detecting mechanism detects the power reception shutoff; and a stand-alone operation executing section that controls said parallel-in/off mechanism, and executes, when the power reception shutoff is detected by said shutoff detecting mechanism, a stand-alone operation in which said parallel-in/off mechanism belonging to said first operation unit selected by said selecting section is caused to parallel in said sodium-sulfur battery to said grid, and said parallel-in/off mechanism belonging to a second operation unit not selected by said selecting section is caused to parallel off said sodium-sulfur battery from said grid.