In a battery apparatus, a battery pack includes a plurality of battery modules and a bus-bar connecting two battery modules among the plurality of battery modules. A wire connects the battery pack and the switch for controlling current supply of the battery pack. A voltage measuring circuit measures a voltage of the bus-bar, a voltage of the battery pack, and voltages of the plurality of battery modules. A processor diagnoses a connection status of the bus-bar and a connection status of the wire based on a current of the battery pack, the voltage of the bus-bar, the voltage of the battery pack, and the voltages of the plurality of battery modules.

A method of calculating a relative state-of-charge (RSOC) of a battery according to the disclosure includes measuring at least one parameter of the battery, based on the at least one parameter, estimating a state-of-charge (SOC) of the battery, based on the SOC, SOC-open circuit voltage (SOC-OCV) data of the battery, and the at least one parameter, estimating a non-dischargeable capacity of the battery, based on the non-dischargeable capacity of the battery, the SOC, and intrinsic capacity of the battery, estimating an available SOC (AvSOC) of the battery, based on the SOC and the AvSOC of the battery, determining the RSOC of the battery, and based on a ratio of the RSOC to the AvSOC, updating the RSOC of the battery.

A battery state estimation method includes acquiring an initial value of a vector-type parameter for modeling an electrochemical-thermal (ECT) model of a battery, extracting a predetermined point from the vector-type parameter based on the initial value, generating a target parameter based on the predetermined point, to minimize an error between an actual state of the battery and a state of the battery acquired from the ECT model, and estimating the state of the battery based on the target parameter.

A battery state estimation method includes acquiring an initial value of a vector-type parameter for modeling an electrochemical-thermal (ECT) model of a battery, extracting a predetermined point from the vector-type parameter based on the initial value, generating a target parameter based on the predetermined point, to minimize an error between an actual state of the battery and a state of the battery acquired from the ECT model, and estimating the state of the battery based on the target parameter.

In a method for estimating a voltage of a battery a given electrochemical battery model is provided, wherein one parameter of the electrochemical battery model is an open circuit potential. The open circuit potential is linearized. The voltage of the battery is estimated by means of the electrochemical battery model with the linearized open circuit potential.

In a method for estimating a voltage of a battery a given electrochemical battery model is provided, wherein one parameter of the electrochemical battery model is an open circuit potential. The open circuit potential is linearized. The voltage of the battery is estimated by means of the electrochemical battery model with the linearized open circuit potential.

A secondary battery status estimation device includes a sensor unit configured to detect a terminal voltage of a secondary battery, and an internal resistance calculator configured to calculate a direct current internal resistance of the secondary battery based on the terminal voltage and the charge-discharge current detected by the sensor unit. The internal resistance calculator calculates a direct current internal resistance based on the terminal voltage and the charge-discharge current detected by the sensor unit, in a stable period that is before starting a driving source for driving a vehicle and in which the terminal voltage and the charge-discharge current of the secondary battery fall within a predetermined fluctuation range, and in a high-current output period in which electric power for starting the driving source is output from the secondary battery and the terminal voltage of the secondary battery is brought to substantially minimum.

A battery control system includes a plurality of battery cells that are separately controllable as units of individual cells or groups of cells. Each controllable unit may be switchably activated or deactivated in the overall battery circuit, and one or more conditions of each controllable unit may be individually measured. Various techniques are disclosed for operating the battery control system to optimize or improve system performance and longevity.

A battery control system includes a plurality of battery cells that are separately controllable as units of individual cells or groups of cells. Each controllable unit may be switchably activated or deactivated in the overall battery circuit, and one or more conditions of each controllable unit may be individually measured. Various techniques are disclosed for operating the battery control system to optimize or improve system performance and longevity.

A method for estimating a battery power percentage of a battery includes: performing a first fuel gauge operation upon the battery; and using the first fuel gauge operation to generate the battery power percentage of the battery by referring to information measured by a second fuel gauge operation performed upon the battery wherein the second fuel gauge operation is different from the first fuel gauge operation.