A method for estimating a battery state of charge may include determining a first estimated state of charge and a first estimated accuracy of the state of charge using a first estimation approach, determining a second estimated state of charge and a second estimated accuracy of the state of charge using a second estimation approach, and estimating the battery state of charge based on the first estimated state of charge, the first estimated accuracy of the state of charge, the second estimated state of charge, and the second estimated accuracy of the state of charge.

A battery cell with a monitoring device including a data processing unit for processing state data of the battery cell as a function of a trigger pulse and a triggering unit, which is connected to the data processing unit, to generate the trigger pulse and to provide the trigger pulse to the data processing unit. The triggering unit is designed to evaluate a measurement signal, which correlates with an electrical energy of the battery cell in order to generate the trigger pulse as a function of the measurement signal. The invention further relates to a battery having such a battery cell as well as to a motor vehicle having such a battery. Furthermore, the invention relates to a method for monitoring at least one such battery cell.

A semiconductor device for measuring a voltage of a battery cell, including first and second nodes, and first and second battery voltage measurement units. The first node is configured to receive a first voltage, the first voltage being a voltage of a capacitor that accumulates an electric charge based on the voltage of the battery cell. The first battery voltage measurement unit measures the first voltage through a first path. The second node is configured to receive a second voltage based on the voltage of the battery cell, the second node being different from the first node. The second battery voltage measurement unit measures the second voltage through a second path that is different from the first path.

Estimation of SOC of a lead-acid battery. Embodiments herein disclose methods and systems for determining State of Charge (SOC) of a lead acid battery in a vehicle. Embodiments herein disclose methods and systems for determining State of Charge (SOC) of a lead acid battery in a vehicle using discharge and charge correction factors. Embodiments herein disclose methods and systems for determining State of Charge (SOC) of a lead acid battery in a vehicle using a master OCV table based SOC estimation (SOC.sub.OCV) after the vehicle has been powered off, and a current throughput based SOC estimation (SOC.sub.EST) based on coulomb count integration (amp-second (As) integration) when the vehicle is operational. Embodiments herein disclose methods and systems for determining State of Charge (SOC) of a lead acid battery in a vehicle considering ageing of the battery and temperature.

A method and a system for determining a discharging process of a battery are provided. The method includes the following steps. Measuring charging/discharging information of the battery. Calculating a charging/discharging characteristic of the battery according to the charging/discharging information. Aligning the charging/discharging characteristic of the battery according to a comparison characteristic point of a comparison characteristic to obtain an aligned charging/discharging characteristic. Determining whether the battery is normal according to the aligned charging/discharging characteristic or a coulombic efficiency of the battery. Calculating a safety probability of the battery according to the aligned charging/discharging characteristic and resistance of an internal short circuit of the battery when the battery is determined as abnormal. Determining a discharging process of the battery according to the safety probability of the battery.

A calibration current load is selectively coupled to an output of a pulse frequency modulated (PFM) DC-DC converter during a calibration operation to increase charge supplied from a battery supplying an input voltage to the converter. A voltage across a sense resistor in series with the battery is integrated during a measurement interval while the calibration current load is coupled to the output. A charge drawn per pulse from the battery is determined based on the sense resistor, the integrated voltage and the number of pulses during the measurement interval. Alternatively, a first PFM frequency is determined with a first calibration current load coupled to the converter output. A second PFM frequency is determined with a second calibration current load. The charge drawn per pulse from the battery is determined based on the first and second PFM frequencies and the first and second calibration current loads.

The charge drawn from a battery during each switching event (pulse) of a pulse frequency modulated DC-DC converter is determined during a calibration period. based on differences in pulse rate with different current loading. Another approach calibration approach determines charge drawn from the battery by measuring voltage across a sense resistor while measuring the total pulse rate and while adding sufficient load current to ensure that the voltage is much larger than the residual offset of the measurement system. During operation, the system counts number of pulses are counted and the total charge drawn from the battery is determined based, at least in part, on the charge transferred per pulse during calibration, the operational mode, the battery voltage during calibration and operationally and the output voltage. Based on the total charge drawn and temperature (for temperature dependent battery types), the battery state of charge is estimated.

A battery's residual energy measurement circuit includes integrated amount measurement circuitry that measures quantity of an integrated amount of current flowing in a battery, time number measurement circuitry that measures number of times by which a sensing operation that changes the current flowing, time measurement circuitry that measures time, and residual energy calculation circuitry that calculates residual energy of the battery using the integrated amount measured within a measurement period by the integrated amount measurement circuitry, the number of times measured within the measurement period by the time number measurement circuitry and the measurement period measured by the time measurement circuitry.

A method for estimating a state of energy of a battery, comprising the steps of estimating a state of charge of the battery, determining a discrepancy between the state of charge and the state of energy as a function of the state of charge, computing the state of energy as a function of the estimated state of charge and of the determined discrepancy. Also a battery including apparatus configured to implement the method is provided.

It is intended to recognize the state of charge or depth of discharge of the battery more accurately than conventional technologies and to recognize health of a battery appropriately. Complex impedance between positive and negative electrodes of the battery is determined at a plurality of frequencies, and the state of charge or depth of discharge of the battery is estimated by comparing frequency dependency of Warburg impedance of the determined complex impedances with frequency dependency of Warburg impedance corresponding to a known state of charge or depth of discharge of the battery. Similarly, complex impedance is determined, and the health of the battery is evaluated by using the real part of the complex impedance at a point where the imaginary part of the complex impedance is zero on a line obtained by extending a part, which indicates frequency dependency of Warburg impedance, of a complex impedance characteristic curve representing a correlation relationship between the real and imaginary parts of the determined complex impedance.