Abstract: An electrochemical storage device including a plurality of electrochemical cells connected electrically in series. Each cell includes an anode electrode, a cathode electrode and an aqueous electrolyte. The charge storage capacity of the anode electrode is less than the charge storage capacity of the cathode.

Abstract: A battery system includes a plurality of electronic storage modules serially connected together wherein the electronic storage modules include a battery block group including a plurality of battery cells, and a different magnetic core connected to each battery block group.

Abstract: A storage battery housing device is provided that comprises a casing that includes a shelf on which a storage battery pack is placed, and a connector that is provided at the rear of the shelf and has the storage battery pack detachably and electrically connected thereto. The storage battery housing device also includes a power reception plug that is connected to an external power source and receives power from the external power source. The storage housing device further includes a charging control circuit that uses the power received by the power reception plug to charge, via the connector, the storage battery pack connected to the connector.

Abstract: A power supply system for a vehicle, which executes the following control, is provided. When a connector coupled to an external power supply is connected to the vehicle, a CHR is set to an on state. When a voltage is lower than a threshold, B2 charging process is executed. When the voltage is higher than the threshold and an SOC1 of a first battery is lower than a threshold, a charging device is stopped and both a first SMR and a second SMR are set to an on state, and B1 charging process is executed. When the SOC1 is higher than or equal to the threshold, the charging device is stopped and both the first SMR and the second SMR are set to an off state.

Abstract: A device for balancing load of a storage device including plural elements connected in series. The device includes: a DC/AC converter including an inverter and a series resonant circuit connected to the output of the inverter; plural AC/DC converters, each including an input and an output that is connected to one of the respective storage elements and selectively supplies power to the output thereof; a transformer, the main winding of which is connected to the series resonant circuit and the secondary winding of which has outputs connected to an input of a respective AC/DC converter; and a control circuit configured to control the DC/AC converter at the current source when a number of outputs supplied with power is no higher than a threshold and moreover configured to control the DC/AC converter at a constant power when the number of outputs supplied with power is greater than the threshold.

Abstract: A device for balancing charge of an electric power storage device including: a plurality of electrical storage elements connected in series including at least two current limiting DC/DC converters each including: an input configured to be connected to terminals of a respective storage element; an output configured to be connected to an electrical network having a voltage controlled at a lower level than the voltage at the terminals of the storage device; a transformation law of following type: Vout=K1*Ve?f(I) for I<=1 lim, in which Vout is potential difference at the output, K1 is a constant, Ve is potential difference at the input, f(I) is an affine function of current I delivered at the output, and 1 lim is current limitation of the converter.

Abstract: An electrochemical energy store with an anode, which is electrically connected to an anode space in which an anode material with a first fill level is arranged, and a cathode, which is electrically connected to a cathode space in which a cathode material with a second fill level is arranged, and an ion-conducting separator, which separates the anode space from the cathode space. The ion-conducting separator has a top region and a base region, wherein at least one conductivity section is provided in the top region of the ion-conducting separator, which conductivity section has greater electrical conductivity during correct operation of the electrochemical energy store than an electrically insulating insulation section in the base region, wherein at least one state of charge of the electrochemical energy store exists in which the anode material makes contact with the conductivity section in the anode space.

Abstract: A battery system including a battery unit including a plurality of battery cells, and a control device including a power supply boot-up unit. The power supply boot-up unit is configured to receive a voltage from the plurality of battery cells, and supply a control signal in response to the voltage supplied by the plurality of battery cells.

Abstract: A method for equalizing states of electric storage devices, which are connected in series, of an electric storage device assembly, includes preparing discharging time period data including discharging time periods associated with sequential numbers, determining whether a voltage of each electric storage device has reached a reference voltage during charging or discharging of the electric storage device assembly, and discharging the electric storage devices, using a discharging circuit, for respective discharging time periods associated with the sequential numbers, the sequential numbers being assigned to the electric storage devices according to a sequence of the electric storage devices determined based on time points at which the voltages of the electric storage devices have reached the reference voltage.

Abstract: The present invention relates to a battery discharging apparatus and a method thereof of a battery management system and an exemplary embodiment of the present invention provides a battery discharging apparatus, including: a battery module including a plurality of battery cells; a discharging element which is connected to the battery cells through switches to discharge a voltage of the battery cells; a detecting unit which detects an abnormal state of a vehicle; and a control unit which is connected to the battery module to monitor a charged/discharged status of the battery cells of the battery module and controls the switches to balance the battery cells, in which when the control unit receives a vehicle abnormal state signal from the detecting unit, the control unit controls the switches to be turned on/off at a predetermined duty ratio to discharge the battery cell.

Abstract: A flying capacitor type voltage detecting device which uses a capacitor to detect a voltage of each battery stack of a battery pack which includes a plurality of battery stacks each of which includes a plurality of battery cells connected in series, includes: a detecting unit that detects a voltage between both ends of the capacitor, as the voltage of each battery stack; and a branch line that is a single line which is branched from a connection line connecting the battery stacks and the detecting unit and connected to the capacitor and where a current during charging of the capacitor and a current during discharging of the capacitor flow in opposite directions.

Abstract: A power storage system comprises the following: a battery unit in which a plurality of battery cells are connected; an acquisition unit for continuously acquiring, while the battery unit is discharging, (V) which represents the extent of the discharge from the battery unit and the temperature (T) of the battery unit when the degree of discharge is (V); a balancing unit for executing cell balancing by which a difference in amount of charging between battery cells is reduced; and a balancing control unit for controlling the balancing unit so that when a reference state is detected based on (V) and (T), cell balancing is not executed, in accordance with a result of the detected reference state.

Abstract: An on-board electrical system for a vehicle comprising: a first energy store; a second energy store; a DC/DC converter bidirectionally transferring energy between the first energy store and the second energy store; and two switching devices for coupling a first terminal of the second energy store to a first terminal of the first energy store via a first node, a second node, and a third node.

Abstract: A power storage system includes a power storage device and a controller. The power storage device includes a plurality of power storage stacks connected in series. The controller controls a discharge processing based on voltage values of power storage elements in each power storage stack. The controller determines an abnormal state according to a voltage fluctuation after the voltage values are made uniform. The controller performs a first processing when the following conditions i) and ii) are satisfied and performs a second processing when the following conditions i) and iii) are satisfied. The condition i) is that the power storage elements included in the plurality of power storage stacks are divided into a plurality of groups, each group consists of the power storage elements included in a same power storage stack. The condition ii) is that the voltage values of the power storage elements are different in each group.

Abstract: A battery monitoring apparatus includes wire sections each connected to a node of corresponding adjacent two of the unit cells of a battery pack at one end thereof, and branched into a first branch section and a second branch section at another end thereof. Each of the first and second branch sections is constituted of a positive part connected to a positive electrode of the corresponding unit cell and a negative part connected to a negative electrode of the corresponding unit cell. The battery monitoring apparatus includes an equalizing switch provided between each of the first wire pairs, and a voltage detector to detect a voltage between each first wire pair, and an equalizing section which performs an equalizing process to equalize a terminal voltage of each unit cell by turning on the corresponding equalizing switch depending on a result of voltage detection by the voltage detector.

Abstract: In a charge/discharge control method of a lithium ion battery having a negative electrode active material and connected to a charge/discharge control device, battery information regarding a charge/discharge state of the lithium ion battery is acquired by the charge/discharge control device, a degradation state of the lithium ion battery is determined on the basis of the battery information, by the charge/discharge control device, and a voltage range for charge/discharge of the lithium ion battery is changed on the basis of a determination result of the degradation state, by the charge/discharge control device.

Abstract: An electric storage system includes electric storage blocks and a controller determining the state of each of the electric storage blocks. The plurality of electric storage blocks are connected in series, and each of the electric storage blocks has a plurality of electric storage elements connected in parallel. Each of the electric storage elements has a current breaker breaking a current path within the electric storage element. The controller acquires at least one parameter of an internal resistance and a full charge capacity of each of the electric storage blocks, and uses a change rate between the acquired parameter and a reference value to specify the number of current breakers in a broken state (the number of breaks) in each of the electric storage blocks. The reference value refers to the value of the parameter in the electric storage block not including the current breaker in the broken state.

Abstract: A method, apparatus and system for networking accessories to a firearm or weapon wherein the accessories are conductively powered from the rail and data is transferred between the accessories and the rail via conductive coupling. In one embodiment, a weapon is provided, the weapon having: an upper receiver; a lower receiver; a powered accessory mounted to a rail of the upper receiver; and an apparatus for conductively networking a microcontroller of the powered accessory to a microcontroller of the upper receiver and a microcontroller of the lower receiver, wherein the data is exclusively provided to the powered accessory from the rail.

Abstract: Techniques effectively prevent an overcurrent from occurring in a system comprising assembled batteries connected in parallel to a power supply line, when a given assembled battery is connected to the power supply line. Multiple battery units are each configured such that they can be connected to a power supply line. Each battery unit includes a battery cell group configured including multiple battery cells, a switching unit arranged between the power supply line and the battery cell group so as to control a current that flows between the power supply line and the battery cell group, and a control unit that controls the switching unit.

Abstract: A battery control unit system is provided that detects a state of a battery used for driving a vehicle and monitors the state of the battery on the basis of detected information so as to control a circuit device surrounding the battery according to a result of the monitoring. The battery control unit system may include an internal power source that is connected directly in parallel with the battery and that supplies power to the battery control unit system, and a microcontroller that operates using the internal power source and detects, by a software process, an on/off-state of a battery pack switch that is provided in a battery pack including the battery and the battery control unit system.

Abstract: A method, apparatus and system for networking and powering accessories to a firearm or weapon wherein the accessories are conductively powered from the rail via at least one pin having a tungsten carbide surface and data is transferred between the accessories and the rail via conductive coupling using the at least one pin. In one embodiment, a weapon is provided, the weapon having: an upper receiver; a lower receiver, the upper receiver being removably mounted to the lower receiver; a powered accessory removably mounted to a rail of the upper receiver; and an apparatus for conductively networking a microcontroller of the powered accessory to a microcontroller of the upper receiver and a microcontroller of the lower receiver.

Abstract: Various techniques described herein relate to electric vehicle power management system for managing a plurality of battery modules in a battery pack. Such electric vehicle power management system may include a plurality of battery management systems corresponding to a plurality of battery modules, and an energy management system for managing the plurality of battery management systems. The energy management system and the plurality of battery management systems may adopt master-slave wireless communication, and may use a single wireless frequency channel or a plurality of assigned wireless frequency channels.

Abstract: [Object] To enable charging/discharging amounts of secondary batteries connected in series to be accurately obtained without increasing the costs. [Solving Means] A power storage apparatus includes a battery section in which a plurality of power storage element sections each including at least one power storage element are connected in series, a cell-balancing circuit that are connected in parallel to a plurality of power storage element sections and performs a cell-balancing operation between plurality of power storage element sections, a control unit that controls the cell-balancing current flowing through the cell-balancing circuit, and an entire-current measurement section that measures a current value of an entire current flowing through the entire battery section and a cell-balancing current measurement section that measures a current value of the cell-balancing current.

Abstract: Disclosed herein is an alternating current linked power converting apparatus, including: a direct current power unit including a plurality of cells, which provide a direct current (DC) voltage and are connected in series, wherein the direct current power unit has both ends connected to an inverter which converts the direct current voltage to an alternating current (AC) voltage; a cell balancing charger/discharger connected to the plurality of cells and balancing the direct current voltage or an amount of charging between the plurality of cells; and a ripple removing capacitor that is positioned between the cell balancing charger/discharger and the inverter and that includes a first terminal and a second terminal that are respectively connected to a first output terminal and a second output terminal of the cell balancing charger/discharger so as to remove ripples of the direct current voltage.

Abstract: A method is provided for balancing the voltage of multiple series-connected electrochemical cells of an electrical storage system of a hybrid electric vehicle. The method includes discharging the electrical storage system by operating at least one large electrical machine of the vehicle at vehicle standstill until the state of charge of the electrical storage system or the cell having the lowest state of charge has reached a predetermined level, and subsequently balancing the voltage of the cells.

Abstract: A storage battery management device manages a plurality of battery units in a storage battery system including the battery units having a plurality of battery cells and a power adjustment device connected to the battery units via respective contactors and connected to a main circuit. The storage battery management device includes a minimum value determination unit and a controller. The minimum value determination unit, from the battery units in which a difference between a maximum cell voltage and a minimum cell voltage of the battery cells forming each of the battery units is equal to or less than a certain value, determines a minimum value of the minimum cell voltage. The controller controls a cell balance process of the battery unit managed by itself, by using the minimum value of the minimum cell voltage determined by the minimum value determination unit as a cell balance target voltage.

Abstract: It is preferable to measure a voltage difference between two electric storage cells with a higher precision while suppressing costs of a balance correction circuit. A balance correction apparatus comprises a first balance correction section which equalizes voltages of two electric storage cells among a plurality of electric storage cells connected in series, a second balance correction section which equalizes voltages of two electric storage cells among the plurality of electric storage cells and a control section which controls operations of the first balance correction section and the second balance correction section. The control section generates a first control signal which controls operations of the first balance correction section and a second control signal which controls operations of the second balance correction section based on a measurement result of each voltage of the plurality of electric storage cells.

Abstract: Systems and methods for battery management are disclosed. A system may include an internal control network including multiple node controllers powered by a unique cell or combination of cells of a battery. The node controllers may communicate with each other via a node communication system. Each node controller may be responsible for managing a charge level associated with one or more cells. The one or more devices of the internal control network may enable measurement of environmental factors such as a temperature and a current and voltage applied at the battery. Based on the measured environmental factors, the internal control network may perform an ongoing assessment of the one or more cells of the battery and of an overall battery condition. The internal control network may initiate turning on or off a battery output to prevent over discharge and possible damage to the battery or devices connected to the battery.

Abstract: A control circuit is configured to monitor and control the operation of a rechargeable battery. The rechargeable battery includes a plurality of interconnected battery cells which are connected to at least one pole connection of the battery by at least one circuit element such that the at least one pole can be electrically decoupled from the rechargeable battery. The control circuit further includes at least one cell monitoring device configured to detect operational parameters of at least one battery cell, and a first control device configured to determine battery properties by evaluating operational parameters. The first control device is connected to the at least one cell monitoring device by a first interface. The control circuit further includes a second control device configured to control the at least one circuit element and which is connected to the at least one cell monitoring device by a second interface.

Abstract: The present invention relates to a method for more efficiently performing a balancing operation for a plurality of battery cells of which charges are not equal, in a battery cell balancing circuit using an LC series resonant circuit. The method may include calculating balancing charge for all battery cells of which the charges are not equal, selecting the strongest battery cell storing the highest charge and the weakest battery cell corresponding to the strongest battery cell, among the entire battery cells, and performing a series of balancing operations.

Abstract: A method and an apparatus for automatically computing work accuracy of a battery management system (BMS) includes the steps of controlling an automobile component simulation module to work, sending a work command to the BMS at the test moment t, and reading a prediction parameter, stopping working when the work command is completed, reading a work parameter and computing state of power (SOP) test accuracy of the BMS, determining whether a temperature of the battery pack exceeds a temperature threshold, if so, controlling a thermal management module to start working, and returning to the determination step, and otherwise, reading a stabilized parameter and performing computation to obtain state of charge (SOC) test accuracy of the BMS.

Abstract: Cell balancing aims to prolong the battery operating life by equalizing the Electro Motive Force (or Open Circuit Voltage) of the participating cells. Even perfectly balanced cells though will exhibit different output voltages because of differences in their internal impedances. The difference in voltage will depend on the load current frequency and intensity. A method is described for re-distributing charge in such a way so when the worst (from the point of view of voltage spread) possible load conditions occur, cells will have similar outputs and none will cross the under-voltage threshold causing a premature shut down of the battery.

Abstract: A method of diagnosing a battery and adaptively adjusting charging modes of the battery includes the steps of initially charging the battery using a constant current mode, wherein the battery is charged by a fix current in the constant current mode; monitoring a deterioration index by a battery management system (BMS), the deterioration index including a highest temperature (Tempmax), an instantaneous temperature difference (?Temp), an instantaneous voltage difference (?V), an instantaneous internal resistance (IRmax), and a state of charge (SoC) of the battery; when Temp exceeds a predetermined temperature threshold, pausing charging the battery; charging the battery by a constant power charging mode when Tempmax becomes smaller than 90% of the predetermined temperature threshold, wherein the battery is charged by a fix electric power in the constant power mode; charging the battery by the constant current charging mode when Tempmax becomes smaller than 50% of the predetermined temperature thresh old.

Abstract: The present invention relates to a technology capable of improving the use time of a battery cell by generally or individually controlling charge or discharge with respect to a multi-battery cell by using LC serial resonance in a module with a multi-battery cell structure. To this end, the present invention includes a battery module including a plurality of serially connected battery cells, a serial resonant circuit including serially connected inductor and capacitor and performing a serial resonant function, and first to third switch units that set an electric energy collection path and an electric energy supply path between the battery module and the serial resonant circuit.

Abstract: Systems and methods for a scalable battery controller are disclosed. In one example, a circuit board coupled to a battery cell stack is designed to be configurable to monitor and balance battery cells of battery cell stacks that may vary depending on battery pack requirements. Further, the battery pack control module may configure software instructions in response to a voltage at a battery cell stack.

Abstract: A balancing circuits and methods for hybrid batteries having two different rechargeable batteries that are coupled in series includes coupling a fuel gauge to each battery to determine the state of charge of each battery, comparing the state of charge of the two batteries, and if the state of charge of the two batteries is more than a predetermined difference, then enabling a switching converter to source current to a node between the batteries or to sink current from the node between the batteries, as required to tend to equalize the state of charge of the two batteries. Otherwise, if the state of charge of the two batteries is equal within a predetermined allowance, then disabling the switching converter.

Abstract: A controlling and computing portion for controlling charge or discharge of a secondary battery comprises an operation mode setting portion for selectively setting a high capacity mode using a first voltage or a long life mode using a second voltage lower than the first voltage, a remaining capacity calculating portion for calculating a relative state of charge from a remaining capacity of the secondary battery and a full charge capacity, a cycle number calculating portion for calculating a cycle number from a calculation result of the remaining capacity calculating portion, and a charge end voltage setting portion for decreasing the first voltage based on the cycle number, and setting the second voltage at a voltage left by subtracting a predetermined voltage from the first voltage in a case where the first voltage becomes equal to or less than a voltage obtained by adding a predetermined value to the second voltage.

Abstract: A storage battery (1) including an electric storage unit (10), an auxiliary electric storage unit (11) connected to the electric storage unit (10) in parallel, a temperature measurement unit (13) measuring a temperature, and a charge and discharge control unit (14) controlling charge and discharge of the electric storage unit (10) and the auxiliary electric storage unit (11), in which the charge and discharge control unit (14) changes an SOC (a charge completion SOC) of the electric storage unit (10) and the auxiliary electric storage unit (11) in a charge completion state of not allowing any more charge according to a measurement result of the temperature measurement unit (13), increases the charge completion SOC of the auxiliary electric storage unit (11) when the charge completion SOC of the electric storage unit (10) decreases, and decreases the charge completion SOC of the auxiliary electric storage unit (11) when the charge completion SOC of the electric storage unit (10) increases.

Abstract: Disclosed are a battery pack protection device and method. The battery pack protection device includes: a sensing unit configured to sense an overcharging state or an overdischarging state of a battery; a plurality of switches installed on a charging path and a discharging path of the battery; a control unit configured to control the plurality of switches so that the battery is both chargeable and dischargeable when the battery is not in the overcharging state or the overdischarging state and control the plurality of switches so that the battery is only dischargeable during overcharging or only chargeable during overdischarging by an output signal of the sensing unit; and a display unit configured to display the charging state or the discharging state of the battery.

Abstract: A method for cell balancing for a plurality of battery cells. Such a method involves the cell balancing being performed on the basis of a need that can be ascertained comparatively accurately. The method described above allows equalization of the states of charge, or cell balancing, based on the state of charge of the battery cells to be made possible, even without knowledge of the capacities of the in particular series-connected battery cells, such that the loss of charge as a result of the cell balancing is particularly low. Hence, a loss of charge as a result of unnecessary equalization of the charge can be prevented or at least significantly reduced.

Abstract: A cell controller in a battery-monitoring device that monitors an assembled battery having a single cell group or a plurality of cell groups, each made up with a plurality of battery cells connected in series, includes: a startup terminal to which a first discharge resistor is connected and a startup voltage is applied; and a cell-balancing unit that executes cell balancing operation in order to adjust charge levels of the plurality of battery cells during a time period through which the startup voltage remains equal to or greater than a predetermined voltage, wherein: the startup voltage is applied for a predetermined length of time by a first timer unit that includes a passive element capable of accumulating electric energy and capable of discharging electric energy to the startup terminal.

Abstract: A vehicular power supply apparatus includes: a first port to which an electric load is connected; a second port to which a first storage apparatus is connected; a third port to which a second storage apparatus is connected; a fourth port to which a power generation apparatus is connected; a first switch disposed between the first and second ports; a second switch disposed between the second and fourth ports; a third switch disposed between the first and third ports; a fourth switch disposed between the third and fourth ports; and a condition switching unit configured to switch between a first condition in which the first and fourth switches are conductive, the second and third switches are cut off, and a second condition in which the first sand fourth switches are cut off, the second and the switches are conductive.

Abstract: A charging and discharging control device includes a pantograph point voltage detection unit configured to detect a pantograph point voltage of a vehicle, a charging and discharging control unit configured to charge a power storage device provided in a vehicle when the pantograph point voltage is greater than or equal to a charging voltage threshold value and discharge the power storage device when the pantograph point voltage is less than a discharging voltage threshold value, a load determination unit configured to determine whether an absolute value of load power for the vehicle is less than a load power threshold value, and a charging and discharging control change unit configured to reduce any one of more of the charging voltage threshold value, the discharging voltage threshold value, and charging/discharging impedance when the absolute value of the load power is less than the load power threshold value.

Abstract: A battery pack management system adjusts the relative state-of-charge of respective battery blocks in a battery pack to equalize (i.e., align, balance or otherwise make similar) the peak battery block voltages (i.e., maximum or “upper peak” battery block voltages when the battery pack is being charged and/or minimum or “lower peak” battery block voltages when the battery is being discharged). Upon detecting an anomalous battery block that exhibits outlier upper and lower peak voltages, the battery pack management system adjusts the relative state of charge of respective battery blocks to center their respective upper and lower peak voltages between operating limits, thus maximizing the operating margin of the battery pack as a whole.

Abstract: A circuit that measures isolation resistance in a battery pack that is associated with a load includes four resistors. Two resistors are connected between terminals of the battery pack and another two resistors are connected in the load in parallel to the resistors in the battery pack. A controller operates two contactors to disconnect the battery from the load and measure first and second voltages in the battery pack and one of the two resistors. The controller operates the two contactors to connect the battery to the load and measures third and fourth voltages in the battery pack and one of the two resistors. The controller identifies the isolation resistance with reference to resistance values of the four resistors and the first, second, third, and fourth measured voltages.

Abstract: This invention reduces degradation of respective lead storage batteries making up a lead storage battery bank and extends the longevity of the lead storage batteries. A lead storage battery system includes an individual battery state measurement unit 102 that measures current, voltage, temperature etc.

Abstract: There is provided a power storage system including at least two battery units mutually connected in parallel, the battery units each including at least one cell and at least one monitor device configured to monitor a charge state, at least one battery charger configured to supply charge current to each of the battery units, and at least one power storage control device configured to control a charge current value that is supplied to each of the battery units. The power storage control device is configured to decrease the charge current value in accordance with the charge state of each of the battery units.

Abstract: This method for restoring battery capacity is provided with an oxygen-generating/exhausting step for charging a nickel-metal-hydride storage battery, causing the generation of oxygen gas in a positive electrode, opening a safety valve device, and discharging at least a portion of the oxygen gas through the safety valve device to the outside of the battery. The battery temperature when starting the step is in the range of ?30 to 10° C. and the SOC is in the range of (30-Ta) to 100%, or the battery temperature (Ta) is in the range of 10 to 50° C. and the SOC is in the range of 20-100%.

Abstract: A battery equalization circuit is provided, including: a positive battery node connecting to a positive node of a battery cell in a battery circuit with a plurality of other battery cells; a negative battery node connected to a negative node of the battery cell; a transformer winding receiving an AC voltage, the transformer winding having an upper transformer node and a lower transformer node; an upper triac connected between the positive battery node and the upper transformer node; a lower triac connected between the negative battery node and the lower transformer node; a control circuit for controlling the upper triac and the lower triac based on a measured cell voltage between the positive battery node and the negative battery node, and a total battery voltage of the battery circuit; and an isolation element connected between the control circuit and a data bus.

Abstract: A compulsory charging and protective circuit for secondary battery after being over discharged is disclosed. The circuit includes a circuit conducting switch, a releasing unit, a triggering unit and a comparing unit. When the secondary battery is over discharged, a temporary electrical connection is provided by the present invention. The loop of the secondary battery and a charger keeps. When the secondary battery recovers from abnormal status, the temporary electrical connection is called off so that the secondary battery can keep normal operation. Thus, when the secondary battery is under over-discharge, it doesn't have to be unloaded for repair to settle the issue. Maintenance costs can be saved.