Abstract: A secondary battery capable of ensuring operator safety by checking whether a service plug is opened or closed. The secondary battery includes a battery pack having a plurality of battery cells, a service plug coupled between each of the plurality of battery cells through a pair of plug terminals for controlling interconnection of the plurality of battery cells according to whether the pair of plug terminals contact the battery cells, and a battery management system connected to the battery pack and the service plug for determining whether the service plug is opened or closed by measuring at least one selected from the group consisting of a voltage and a current of the battery pack and voltages of the plurality of battery cells connected to the service plug.

Abstract: A secondary battery includes a plurality of battery cells and measures voltages of the battery cells. The secondary battery includes a capacitive device, a relay and an A/D converter. The capacitive device is connected to the battery cells to sequentially store the voltages of the battery cells. The relay is between the battery cells and the capacitive device, and sequentially connects the battery cells to the capacitive device. The A/D converter is connected to the capacitive device to receive and convert the voltages of the battery cells.

Abstract: A battery management system capable of safely disconnecting a charge/discharge current line from a battery pack in an over-charge condition is provided. The battery management system includes a charge/discharge relay including a relay switch coupled to a charge/discharge current path of a battery pack and a driving coil for driving the relay switch, a relay driving unit for controlling the driving coil, a motor control unit (MCU) for controlling the relay driving unit, the MCU being coupled to the relay driving unit, a switching device being coupled between the driving coil and the relay driving unit, and a switching control unit for controlling on/off operations of the switching device to control a current of the relay driving unit.

Abstract: A secondary battery includes a plurality of battery cells and measures voltages of the battery cells. The secondary battery includes a capacitive device, a relay and an A/D converter. The capacitive device is connected to the battery cells to sequentially store the voltages of the battery cells. The relay is between the battery cells and the capacitive device, and sequentially connects the battery cells to the capacitive device. The A/D converter is connected to the capacitive device to receive and convert the voltages of the battery cells.

Abstract: A battery management system capable of safely disconnecting a charge/discharge current line from a battery pack in an over-charge condition is provided. The battery management system includes a charge/discharge relay including a relay switch coupled to a charge/discharge current path of a battery pack and a driving coil for driving the relay switch, a relay driving unit for controlling the driving coil, a motor control unit (MCU) for controlling the relay driving unit, the MCU being coupled to the relay driving unit, a switching device being coupled between the driving coil and the relay driving unit, and a switching control unit for controlling on/off operations of the switching device to control a current of the relay driving unit.

Abstract: A secondary battery capable of ensuring operator safety by checking whether a service plug is opened or closed. The secondary battery includes a battery pack having a plurality of battery cells, a service plug coupled between each of the plurality of battery cells through a pair of plug terminals for controlling interconnection of the plurality of battery cells according to whether the pair of plug terminals contact the battery cells, and a battery management system connected to the battery pack and the service plug for determining whether the service plug is opened or closed by measuring at least one selected from the group consisting of a voltage and a current of the battery pack and voltages of the plurality of battery cells connected to the service plug.