Battery monitoring

A control apparatus configured to communicate with a power storage apparatus configured to accumulate power, comprising:

• a communication unit configured to
• receive from the power storage apparatus via a network of a consumer's facility, at least one first message indicating an existence of non-existence of a function of notifying a rated output of the power storage apparatus,
• transmit to the power storage apparatus via the network, at least one second message requesting notification of the rated output of the power storage apparatus, based on the at least one first message received from the power storage apparatus,
• receive from the power storage apparatus via the network, a third message comprising a first information element indicating a first rated output of the power storage apparatus in a grid connection state in which the power storage apparatus is connected to a grid, based on the at least one second message, and
• receive, from the power storage apparatus via the network, a fourth message comprising second rated output of the power storage apparatus in a self-sustained state in which the power storage apparatus is disconnected from the grid, based on the at least one second message;
• and
• a controller that
• controls, via the network, a charge and/or discharge of the power storage apparatus based on the first rated output in the grid connection state indicated by the third message, and
• controls, via the network, a charge and/or discharge of the power storage apparatus based on the second rated output in the self-sustained state indicated by the fourth message.

A power storage apparatus configured to accumulate power, comprising:

• a communication unit configured to
• transmit, to a control apparatus configured to communicate with the power storage apparatus via a network of a consumer's facility, at least one first message indicating an existence or non-existence of a function of notifying a rated output of the power storage apparatus,
• receive, from the control apparatus via the network, at least one second message requesting notification of the rated output of the power storage apparatus, based on the at least one first message received from the power storage apparatus,
• transmit, to the control apparatus via the network, a third message comprising a first rated output of the power storage apparatus in a grid connection state in which the power storage apparatus is connected to a grid, based on the at least one second message, and
• transmit, to the control apparatus via the network, a fourth message comprising a second rated output of the power storage apparatus in a self-sustained state in which the power storage apparatus is disconnected from the grid, based on the at least one second message;
• wherein the power storage apparatus charges or discharges according to a control by the control apparatus via the network that is based on the first rated output in the grid connection state indicated by the third message and that is based on the second rated output in the self-sustained state indicated by the fourth messages.