Voltage and Current Monitoring Systems for EV Batteries

Diagnosing abnormalities in voltage behavior of batteries based on changes in differences between measured open circuit voltage data and estimated open circuit voltage data over time. The method involves generating open circuit voltage (OCV) data from the battery, deriving estimated OCV data based on the measured data, and diagnosing battery health based on the difference between the measured and estimated OCV values. This allows detecting subtle voltage abnormalities even when the battery voltage itself doesn't change significantly.

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Controlling battery charging to prevent lithium plating on anode surfaces through a novel voltage-based charging strategy. The approach measures the potential difference between reference and anode terminals in each cell and determines the charging current based on the minimum anode potential. This approach prevents lithium deposition by directly controlling the charging current based on the anode potential, eliminating the need for traditional lithium deposition rate measurement. The strategy ensures optimal charging conditions for each cell while preventing excessive lithium deposition.

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A diagnostic system for discharge circuits in electric vehicles that can detect if the discharge circuit is functioning properly. The system includes a sensor connected in series with the discharge circuit. During a diagnostic check, the control system operates the discharge circuit to dissipate charge. If the sensor detects no change in electrical characteristic, it indicates the discharge circuit is deficient and provides a notification. This allows proactive detection of faulty discharge circuits to prevent issues like incomplete charge dissipation during vehicle shutdown.

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Discharge device for secondary batteries that optimizes charging and discharging while maintaining battery health. The device employs a controlled discharge strategy that transitions from primary discharge to secondary discharge at specific voltage and current rates. This approach maintains the battery's state of charge while preventing excessive stress on the cells. The device includes sensors to monitor battery voltage, current, and temperature, enabling real-time adjustments to the discharge parameters. The controlled discharge strategy ensures safe and efficient battery management, particularly for batteries nearing the end of their lifespan.

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Predicting damage to battery cells by monitoring voltage and temperature within a damage range and calculating a weighting factor based on the readings. If the cell's voltage or temperature falls within the damage range, the cell is disconnected to prevent further damage. The weighting factor is accumulated over time to determine the overall damage level. If the accumulated weighting exceeds a threshold, the cell is permanently blocked. This allows managing cells based on damage history and replacing them at appropriate intervals.

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Battery monitoring system for electric vehicles that allows synchronized acquisition of battery voltage and current data without wired connections. The system uses wireless communication between a central monitoring device and individual battery measurement devices. The monitoring device sends voltage measurement commands to the battery devices at regular intervals. The battery devices measure voltage at those times. The monitoring device then synchronously acquires current data from onboard sensors during the same time intervals to match the voltage measurements. This allows calculating battery resistance without requiring precise timing coordination.

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Battery pack design and protection method to prevent reverse voltage damage when a cell fuse blows in a battery pack. The pack has balancing resistors, switches, and a current sensor between the pack terminals. If a cell fuse blows, the controller detects the increased pack current and turns on all the balancing switches to form a closed circuit through the resistors. This limits reverse voltage across the blown fuse to protect the cell. If a short is detected, it turns on all balancing switches. After a short, it checks for fuse blowout.

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Battery management system (BMS) using optical communication between batteries instead of wires to address issues like cyber-attacks, EMI, bulky wiring, and slow data transfer. The BMS has optical devices connected to each battery that emit and receive optical signals containing battery data through transparent and reflective films. The signals bounce between films to transfer between batteries. This allows fast, immune, and secure battery monitoring without wires.

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An electronic current control system for autonomous vehicles that automatically limits electrical current to pulsed or switching electronics like motors and LIDAR sensors without latency or user intervention. The system adds a current monitor component to the electrical pathway between the power supply, current control component, and pulsed/switching electronics. The monitor adjusts the current control component based on a threshold voltage compared to the output voltage, without needing the main processor. This provides faster, localized current limiting to prevent unsafe thermal events in the pulsed electronics.

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Battery diagnosis system that rapidly identifies low voltage cells in lithium-ion batteries through a novel approach combining voltage deviation analysis and rate of change detection. The system collects resting voltages during charging and discharging phases, calculates deviations from a representative baseline, and analyzes their rates of change over time. By comparing these deviations against predetermined thresholds, the system identifies cells exhibiting significant deviations from normal behavior, which are then further evaluated through linear regression analysis to confirm their low voltage status. This approach enables rapid and accurate identification of potential battery faults compared to traditional methods that rely solely on voltage readings.

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Compensating battery cell sampling voltages in a multi-module battery pack to accurately measure cell voltages. The method involves charging/discharging the pack with a stable current to determine impedance of cross-module busbars. This impedance is used to compensate voltages of cells near busbars. By checking all pack cells are normal first, it ensures accurate impedance calculations. This prevents voltage errors from long busbar lengths.

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A power storage pack for electric vehicles and charging stations that can efficiently measure contact resistance between the vehicle and charger after mounting to ensure proper connection and prevent issues like erroneous battery control. The pack has a controller that authenticates with the vehicle/charger using a current pattern over the power lines. By measuring voltages and current during authentication, the pack can determine contact resistance. This allows detecting any abnormal resistance changes due to loose connections, enabling proactive fault diagnosis.

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Differentiating and responding to short circuiting in batteries, particularly lithium secondary batteries, to improve safety and performance. The system involves detecting battery behavior during short circuits, comparing it to predetermined profiles, and taking appropriate mitigating actions based on the type of short circuit detected. This allows differentiating between different short circuiting behaviors and responding aggressively versus passively based on the analysis. The detection involves monitoring battery parameters like temperature, heat generation, current, voltage drop.

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System for mitigating degradation of batteries in electric vehicles by monitoring and managing operating conditions of individual battery modules. The system involves sensors on the modules to generate operational data, which is transmitted to a central component that analyzes the data to determine the module's operating condition. This allows identifying if the module is being operated in a way that accelerates degradation. By monitoring and managing module operating conditions, battery degradation can be mitigated.

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High-precision current detection method for lithium batteries and other applications that involves using a specialized integrated chip to accurately measure small currents without degradation from resistive losses or temperature drift. The chip has a current sampling switch connected in series with the protected current path, and a high-precision operational amplifier to amplify and convert the sampled current into a voltage signal. This amplified voltage is then read by a separate metering unit to provide an accurate representation of the original current. The amplification gain is adjusted based on the specific current loop parameters to optimize performance for different load current ranges. This allows precise current measurement using a small sampling resistor without sacrificing accuracy due to signal attenuation. The chip integrates the current sampling and metering functions to reduce interconnection issues and improve signal-to-noise ratio compared to separate components.

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Calculating state of charge (SOC) of a battery module during discharging to prevent sudden drop below a minimum allowed level. The method involves calculating a correction factor for SOC based on voltage, discharge current, and load resistance when the voltage is below a threshold. This speeds up SOC decrease so it reaches a preset value when the voltage drops to the minimum allowed level. This avoids abrupt SOC drops during discharging that could lead to abnormal consumption and user issues.

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Electrical module and battery pack design for improving voltage and temperature collection accuracy in electric vehicles. The design brings the cell voltage and temperature sensors closer to the module's electrical interface to reduce signal transmission length. This is done by integrating the sensor circuitry into the module instead of using separate sensors and cables. The module has a cells contact system to collect voltages and temperatures, and an on-board cell supervision circuit with analog front ends to convert the signals. This reduces the length of analog signal transmission compared to conventional designs with separate sensors and cables. The closer proximity of the sensors to the module interface reduces transmission path interference and improves voltage and temperature accuracy.

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Detecting abnormal cells in a battery pack with multiple cells connected in series or parallel blocks. The method involves monitoring relative voltage changes between cells during constant voltage (CV) charging. If a cell's voltage drops more than the others in CV, it indicates an issue like internal resistance increase. This allows detecting faulty cells without needing individual cell voltage thresholds.

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Method and system for estimating battery state of charge (SOC) that provides accurate and adaptive SOC estimation in various load, temperature, capacity, and aging conditions. The method involves calculating a voltage difference using a voltaic gauge and an open-circuit voltage. It then adaptively adjusts a gain using a gain control engine based on battery current and full charged capacity. This adjusted gain is used to generate the SOC change.

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Detecting defective battery cells in a battery pack to improve performance and longevity. The method involves monitoring the charge and discharge voltages of each cell over multiple charge/discharge cycles. If a cell consistently reaches full charge or empty discharge before others, it's flagged as defective after a certain number of cycles. This indicates accelerated degradation and potential issues like cell balancing and capacity loss.

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