A power supply system is described. The power supply system can include an active power contactor, a standby power contactor, an auxiliary power contactor, a control switch, and a controller. The active power contactor is connected in series in a path of a main power supply circuit, and the standby power contactor is connected in series in a path of a standby power supply circuit. The active power contactor and the standby power contactor are interlocked through the auxiliary power contactor. The auxiliary power contactor and the control switch are connected in series. The controller is configured to when the main power supply circuit is abnormal, control the control switch to change a status of the auxiliary power contactor, to switch to the standby power supply circuit, or control the control switch to change the status of the auxiliary power contactor, to switch to the main power supply circuit.

A backup battery control module configured to supply electric power from a backup battery to a load when electric power supplied from a main battery to the load is cut off. The backup battery control module is configured to: measure an open circuit voltage of the backup battery in a state in which an ignition switch is off; derive, based on a measured open circuit voltage, an already charged rate of the backup battery; measure an internal resistance of the backup battery in a state in which the ignition switch is off; derive a deterioration degree of the backup battery based on a measured internal resistance; derive a target charging rate based on the deterioration degree; and charge the backup battery until the target charging rate is reached in a case in which it is determined that the already charged rate is smaller than the target charging rate.

A backup battery control module configured to supply electric power from a backup battery to a load when electric power supplied from a main battery to the load is cut off. The backup battery control module is configured to: measure an open circuit voltage of the backup battery in a state in which an ignition switch is off; derive, based on a measured open circuit voltage, an already charged rate of the backup battery; measure an internal resistance of the backup battery in a state in which the ignition switch is off; derive a deterioration degree of the backup battery based on a measured internal resistance; derive a target charging rate based on the deterioration degree; and charge the backup battery until the target charging rate is reached in a case in which it is determined that the already charged rate is smaller than the target charging rate.

A manually controlled coupling mechanism for onsite energy generation and storage systems includes a first contact portion having a first electrical contact for coupling to an utility grid and a second electrical contact for coupling to an on-grid AC terminal of an inverter, a second contact portion having a third electrical contact for coupling to an off-grid output terminal of the inverter, and a manually activated multi-position switch, wherein in a first position, only the first contact portion is activated to allow power transfer between the utility grid, the on-grid AC terminal of the inverter and a main electrical panel, and in the second position, only the second contact portion is activated to allow power transfer from the off-grid output terminal of the inverter to the main electrical panel.

A manually controlled coupling mechanism for onsite energy generation and storage systems includes a first contact portion having a first electrical contact for coupling to an utility grid and a second electrical contact for coupling to an on-grid AC terminal of an inverter, a second contact portion having a third electrical contact for coupling to an off-grid output terminal of the inverter, and a manually activated multi-position switch, wherein in a first position, only the first contact portion is activated to allow power transfer between the utility grid, the on-grid AC terminal of the inverter and a main electrical panel, and in the second position, only the second contact portion is activated to allow power transfer from the off-grid output terminal of the inverter to the main electrical panel.

The systems and methods herein described isolating a circuit breaker panel for a building from a grid circuit during an event disrupting the grid circuit. In one aspect, a interrupt switch system comprises a housing configured to mate with an electric meter socket on a first side and an electric meter on a second side, the housing comprising power inputs from grid power and power outputs to a circuit breaker panel and an interrupt circuit disposed within the housing and configured to interrupt a flow of electricity from the power inputs to the power outputs.

The embodiments of a “SAVUS” disclosed herein are simple, safe, low cost devices used to connect emergency power to an entire home. The embodiments of SAVUS are configured to install into most residential types of circuit breaker front panels and require only one available circuit breaker space for installation. SAVUS mechanically interlocks with the main circuit breaker and will not allow connection of an external power source to the circuit breaker box until utility power is turned off for safety.

In a relay operation state maintaining device configured to maintain an operation state of a relay when an abnormality occurs in a controller configured to control an operation of the relay, the relay operation state maintaining device includes: a memory configured to store a relay control signal output for an operation of the relay by the controller at a time the abnormality occurs and to generate and output a memory output signal based on a stored signal; a first relay driving signal generator configured to generate and output a first relay driving signal based on the relay control signal and a signal corresponding to the abnormality occurrence; and a second relay driving signal generator configured to generate and output a second relay driving signal based on the first relay driving signal and the memory output signal.

In a relay operation state maintaining device configured to maintain an operation state of a relay when an abnormality occurs in a controller configured to control an operation of the relay, the relay operation state maintaining device includes: a memory configured to store a relay control signal output for an operation of the relay by the controller at a time the abnormality occurs and to generate and output a memory output signal based on a stored signal; a first relay driving signal generator configured to generate and output a first relay driving signal based on the relay control signal and a signal corresponding to the abnormality occurrence; and a second relay driving signal generator configured to generate and output a second relay driving signal based on the first relay driving signal and the memory output signal.

A method of charging a battery and a system using the same are provided. The method includes: detecting a terminal voltage of a battery; When the terminal voltage is less than a voltage threshold, performing quick charging which includes: calculating a rising rate of the terminal voltage, comparing the rising rate with a rising rate reference value, and controlling the terminal voltage according to the comparison result; and when the terminal voltage is not less than the voltage threshold, performing low current floating charging which includes: intermittently charging the battery by a predetermined floating charging period, calculating a falling rate of the terminal voltage, comparing the falling rate with a falling rate reference value, controlling the terminal voltage according to the comparison result, in a first time duration of the floating charging period, and suspending charging in a second time duration of the floating charging period.