The cell balance circuit is a circuit connected in parallel to a secondary battery including a battery pack in which a first cell to an n.sup.th cell (n is plural) are connected in series in order from a positive electrode to a negative electrode and adjusting individual voltages of n cells. The cell balance circuit includes a switch circuit which can respectively open/close paths connected to n cells, and a cell discharge resistor respectively connected to the first cell to the n.sup.th cell via the switch circuit. The switch circuit switches to a cell balance stop state where each of the first cell to the n.sup.th cell is not connected to the cell discharge resistor in at least one state of a state where a charger is not connected to an external terminal, or a state where the secondary battery is being discharged to a load.

The present invention provides a battery equalizing apparatus and method, and an unmanned aerial vehicle (UAV). The battery equalizing apparatus includes: a battery gauge configured to monitor battery level information of a battery in a static state, a battery equalizing circuit being disposed inside the battery gauge; and a microprocessor connected to a communication port of the battery gauge and configured to: acquire the battery level information monitored by the battery gauge, and calculate a pressure difference between cells of the battery in a static state according to the battery level information, and determine whether the pressure difference is greater than a pressure difference threshold; the microprocessor sending a trigger signal to the battery gauge through the communication port when the pressure difference is greater than the pressure difference threshold, to trigger the equalizing circuit of the battery gauge to equalize the battery. Through implementation of the present invention, a space of a circuit board may be saved by using an internally integrated equalization function of the battery gauge, facilitating miniaturization of the battery.

A device, for a low-voltage circuit, includes a four-pole input connection for a three-phase AC circuit having a neutral conductor, including a first, second and third input phase pole, and an input neutral conductor pole; a two-pole output connection; a first connection between the between the input and output neutral conductor pole; a first, second and third electronic switch unit to carry out opening and closing of an electrical connection; a voltage sensor for determining the voltage level of the input phase poles; and a controller connected to the voltage sensor and the electronic switch units, designed such that, depending on the voltage level of the input phase poles, the first, second or third input phase pole is connected to the first output phase pole via the respective electronic switch unit, the first output phase pole being connected to the respective input phase pole having the highest voltage level.

Disclosed are a communication method between a master controller and slave controllers, a slave controller for the communication method, and a battery management system using the communication method and the slave controller, in which the master controller receives safety information about battery cells through a plurality of channels even when each of a plurality of slave controllers includes only one micro controller unit, thereby minimizing the increase in the cost and enhancing the safety of the battery management system. The communication method includes performing bidirectional communication between a master controller and first to N.sup.th (where N is an integer equal to or more than two) slave controllers through a first communication channel, and receiving, by the master controller, an indication signal through a second communication signal via the first to N.sup.th slave controllers.

Provided is a power supply device which includes a plurality of battery modules and in which the battery modules are connected in series with one another in accordance with a gate driving signal from a controller. The power supply device includes a disconnecting part configured to forcibly isolate the battery module from a series connection regardless of the gate driving signal, and limits, in accordance with a target output voltage value, a number of the battery modules to be forcibly isolated by the disconnecting part.

A battery management apparatus according to the present disclosure may include a sensing unit detachably mounted to a battery system and configured to measure a voltage of a cell assembly included in a battery pack, which is electrically connected to another battery pack in parallel, when being mounted to the battery system; a balancing circuit having a balancing resistor connected to a charging and discharging path of the cell assembly in parallel and a balancing switch for electrically connecting or disconnecting the cell assembly and the balancing resistor; and a processor operably coupled to the sensing unit and the balancing circuit.

A charging cable has a current sensor, a charging state indicator and logic circuitry to operate the indicator based on detected levels of current flow to a chargeable device. If the sensor detects current below a low threshold, the logic circuitry operates the indicator to indicate that the cable is not connected to any chargeable device. If the sensor detects current above a higher threshold, the logic circuitry operates the indicator to provide a perceptible output indicating that the cable is connected to the chargeable device and the current is charging the battery. If the sensor detects current at or above the low threshold but below the high threshold, the logic circuitry operates the indicator to provide a perceptible output indicating that the cable is connected to a chargeable device but is not charging the battery of the device, e.g., when the battery is, or is nearly, fully charged.

A battery system, control device, and control method are provided that can improve the cycle service life. One aspect of the present invention is a battery system comprising: a plurality of battery units including at least one battery cell that has a negative electrode that is free of a negative electrode active material; a plurality of switches that can switch between a first state in which a battery unit is connected to a charging pathway or a discharge pathway, and a second state in which a battery unit is not connected to the charging pathway or the discharge pathway; a charge control unit; and a discharge control unit, wherein the charge control unit includes a first switch control unit that simultaneously sets “a” (where “a” is an integer equal to or greater than 2) selected switches to the first state and sets the remaining switches except the “a” switches to the second state, and the discharge control unit includes a second switch control unit that simultaneously sets “b” (where “b” is an integer less than “a”) selected switches to the first state and sets the remaining switches except the “b” switches to the second state.

In a power supply system, a control device is configured to adjust a state of charge of each of an alternating-current battery string and a direct-current battery string by power transfer between the alternating-current battery string and the direct-current battery string before performing requested energy management.

A power supply system includes an alternating current sweep unit and a first power supply circuit, and each of a U-phase battery string, a V-phase battery string, a W-phase battery string, and a first battery string includes a plurality of battery circuit modules connected in series, and each of the battery circuit modules includes a battery, output terminals, a first switch, and a second switch.