The present invention relates to a method for determining a state of charge of a battery, including: (a) acquiring a state of charge of the battery at a current sampling time point tn; (b) acquiring a voltage Vn, a temperature Tn, and a charging rate Cn of the battery at the current sampling time point tn, and a voltage Vi of the battery at a sampling time point ti, and calculating a voltage difference Vn−Vi between the voltage Vn and the voltage Vi; (c) when the voltage difference Vn−Vi is greater than or equal to a preset voltage threshold, calculating a voltage change rate; and (d) when the voltage change rate is greater than or equal to a preset voltage change rate threshold for the first time, acquiring a corrected state of charge of the battery as an actual state of charge of the battery.

The present invention relates to a method for determining a state of charge of a battery, including: (a) acquiring a state of charge of the battery at a current sampling time point tn; (b) acquiring a voltage Vn, a temperature Tn, and a charging rate Cn of the battery at the current sampling time point tn, and a voltage Vi of the battery at a sampling time point ti, and calculating a voltage difference Vn−Vi between the voltage Vn and the voltage Vi; (c) when the voltage difference Vn−Vi is greater than or equal to a preset voltage threshold, calculating a voltage change rate; and (d) when the voltage change rate is greater than or equal to a preset voltage change rate threshold for the first time, acquiring a corrected state of charge of the battery as an actual state of charge of the battery.

The present application provides a method and apparatus for correcting a state of charge. The method for correcting a state of charge comprises: determining an operating state of a battery cell, wherein the operating state comprises a discharging state or a charging state; and determining a corrected state of charge of the battery cell according to an acquired current open circuit voltage of the battery cell, an acquired current accumulative capacity of the battery cell, an accumulative capacity correspondence relationship corresponding to the operating state of the battery cell, and an open circuit voltage curve corresponding to a limit initial state of charge, wherein the accumulative capacity correspondence relationship comprises a correspondence relationship between a pre-measured open circuit voltage and an accumulative capacity threshold. A technical solution of the present application can be used to improve the accuracy of calculation of a state of charge.

Disclosed are methods, systems, and devices for battery formation. A first set of pulses, having a first frequency, and that carry a net zero charge, are applied to a battery. After the first set of pulses are applied to the battery, a second set of pulses that carry a net positive charge are applied to the battery. The second set of pulses are either applied after expiry of a particular time period following the application of the first set of pulses, or based on some battery measurements. After the second set of pulses are applied to the battery, a battery parameter is measured, and based on the measured battery parameter, a third set of pulses, having a second frequency, and that also carry a net zero charge, are applied to the battery.

Disclosed are methods, systems, and devices for battery formation. A first set of pulses, having a first frequency, and that carry a net zero charge, are applied to a battery. After the first set of pulses are applied to the battery, a second set of pulses that carry a net positive charge are applied to the battery. The second set of pulses are either applied after expiry of a particular time period following the application of the first set of pulses, or based on some battery measurements. After the second set of pulses are applied to the battery, a battery parameter is measured, and based on the measured battery parameter, a third set of pulses, having a second frequency, and that also carry a net zero charge, are applied to the battery.

A terminal device, a method for monitoring battery safety of a terminal device, and a system for monitoring battery safety of a terminal device are provided. The method for monitoring battery safety includes the following. Acquire status information of a battery of the terminal device. Determine whether the terminal device meets a preset safety hazard condition according to the status information. Upon determining that the terminal device meets the preset safety hazard condition, control the terminal device to be in a power-off state or disconnect a power supply circuit.

A terminal device, a method for monitoring battery safety of a terminal device, and a system for monitoring battery safety of a terminal device are provided. The method for monitoring battery safety includes the following. Acquire status information of a battery of the terminal device. Determine whether the terminal device meets a preset safety hazard condition according to the status information. Upon determining that the terminal device meets the preset safety hazard condition, control the terminal device to be in a power-off state or disconnect a power supply circuit.

The present disclosure relates to an apparatus for estimating a battery free capacity, and more particularly, an apparatus for estimating a free capacity of a half cell of a battery. According to the present disclosure, it is possible to accurately estimate a free capacity of a half cell without inserting a reference electrode by revising an entire SOC region of a half cell by using an inflection point detected based on SOC-voltage data of a full cell and a half cell of the battery, respectively, and then estimating SOC-voltage data based on a SOC difference between the entire SOC regions before and after the revision.

The present disclosure relates to an apparatus for estimating a battery free capacity, and more particularly, an apparatus for estimating a free capacity of a half cell of a battery. According to the present disclosure, it is possible to accurately estimate a free capacity of a half cell without inserting a reference electrode by revising an entire SOC region of a half cell by using an inflection point detected based on SOC-voltage data of a full cell and a half cell of the battery, respectively, and then estimating SOC-voltage data based on a SOC difference between the entire SOC regions before and after the revision.

A method is provided for calibrating a passive balancing system in a battery system which has a plurality of lithium ion cells and a battery management system, in which cell units consisting of individual cells or parallel-connected groups of a plurality of cells are each provided with a discharge circuit having a load resistance Ri representing the calibration parameter, and the cell units are serially connected in series. The battery management system is designed to measure the voltage U.sub.i of each cell unit and to actuate the discharge circuit at a selectable time in order to discharge the cell unit in a controlled manner via the load resistance R.sub.i. The method includes actuating the discharge circuit of the cell unit for a discharge time t.sub.i in order to remove a charge Q.sub.i, and determining t.sub.i, Q.sub.i and the voltage characteristic over time U.sub.i(t); and determining R.sub.i.