A Deep Look Into BYD's Battery Management System (BMS)

Battery tray assembly for detecting electrical short circuits and leaks in electric vehicle battery packs. The assembly has an electrically conductive member in the tray that connects to a reference potential point. If an electrically conductive medium like electrolyte leaks into the tray, it completes a circuit between the battery and reference point. A battery management system can detect voltage differences between the battery and reference point to indicate medium presence. This allows early detection of leaks or shorts in the tray before they become serious issues.

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Battery device and electronic device design to prevent battery over-discharge during storage and transportation. The battery device has a separable connection between the battery cell group and management system. The battery cell group is connected to the first end for charging/discharging, the management system is connected to the second and third ends for powering. Disconnecting the first and third ends puts the battery in a power-off state with disconnected cell group. This prevents self-discharge and over-discharge during storage. Connecting them puts the battery in a power-on state with connected cell group.

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Power supply system with improved reliability and flexibility compared to prior art charging systems. The system allows charging any battery pack in the system, isolating failed packs, adjusting conversion efficiency, providing backup power during grid outages, and connecting multiple power exchange cabins. It uses a bidirectional converter, power conversion management, and battery pack management. The converter charges any pack, isolation cuts faulty packs, efficiency adjustment prolongs converter life, reverse power provides backup during grid outage, and multiple cabins enable distributed charging.

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Battery management system for vehicles that provides safety, isolation, and power distribution for multiple battery packs. The system has a central unit with a combining module to connect multiple battery packs. It allows packs to be disconnected and replaced while the others continue supplying power. The system also balances pack output to meet demand, transfers charge between packs, and isolates abnormal packs.

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Battery circuit for electric vehicles that allows faster and more reliable over-temperature protection compared to conventional methods. The circuit uses a series of temperature acquisition boards connected between the battery modules and the main battery switch. If a module's temperature is abnormal, the acquisition board disconnects and prevents the main switch from receiving the normal setpoint. This allows immediate localized disconnection of the module without relying on centralized software or CAN communication.

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Battery management method for vehicles that ensures safe use and longevity of the battery when the vehicle is parked. The method involves checking if the vehicle is locked and parked, then retrieving weather forecasts for the near future. Based on the forecasts, the battery is managed. This includes thermal management of the main traction battery when conditions warrant, as well as smart charging of the secondary starting battery. The goal is to optimize battery performance and prevent damage in extreme weather.

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A battery management system that simplifies calibration and identification of multiple battery branches in a parallel system without manual sequential calibration. The system uses circuit signal collectors like current sensors in each branch to monitor branch performance. It identifies and calibrates the collectors using a control module. When power is applied to a collector, the module sends target identification to it. This allows the collector to transmit its branch data to the system using the stored target ID.

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Equalizing a battery pack to improve battery utilization and lifespan. The method involves determining the high voltage turning point of the charging curve for each cell in the pack. This point represents the end of the linear charging region. By finding this point, the actual capacity of the cell can be determined. The cells are then equalized based on their actual capacities instead of just the nominal capacity. This prevents overcharging and undercharging of cells during equalization.

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Sampling device for battery management systems that eliminates the need for wire harnesses and connectors between battery modules and the acquisition module. The device uses a cascading architecture with core functional regions, auxiliary functional regions, and connection tips. The core regions handle battery data, the auxiliary regions transmit signals, and the tips connect to the battery. This allows the core regions to acquire battery info through the auxiliary regions instead of wiring. The cascading connection between core regions replaces the multiple wiring connections.

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Battery pack equalization system for electric vehicles to improve battery consistency and lifetime. The system has a controller that monitors cell voltages during charging and discharging. If it detects significant voltage imbalance, it enables equalization mode. In equalization mode, the controller actively balances cell voltages by selectively charging or discharging cells based on their state of charge. This aims to levelize cell voltages and prevent capacity loss due to unequal charge distribution. The equalization is done periodically during regular charging/discharging cycles to avoid prolonged standalone equalization.

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Battery management system that enables fast charging and discharging of lithium batteries at low temperatures. The system uses an internal heating circuit to generate heat inside the battery. This is done by converting DC to AC and applying the resulting current to specific points on the battery electrodes. The heating circuit can be controlled based on battery temperature. This allows evenly distributed heating of the battery core to prevent cold spots. By providing internal heating, the battery can charge and discharge at low temperatures without limitations. It also avoids using external heating pads which are bulky and inefficient. The heating circuit can be integrated into the battery management system.

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Battery module design for lithium-ion power batteries that improves reliability, maintainability, and manufacturability compared to conventional modules. The module has an integrated battery management system (BMS) inside the cell support bracket instead of separate components. This allows direct connection of the BMS circuitry to the cells without wiring and reduces space requirements. The BMS detects cell parameters, manages charging/discharging, and provides fault protection. The integrated BMS improves accuracy, reduces failures, and simplifies module assembly.

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Temperature regulating system for electric vehicle batteries that precisely controls heating and cooling power based on actual battery state to prevent overheating and undercooling. The system uses a controller to calculate required power to reach a target temperature based on initial temp, target temp, and time. It also measures actual power during regulation. This allows adjusting heater/cooler power to match the required power for accurate temperature control.

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Method and device for accurately estimating battery state of charge in electric vehicles that accounts for measurement errors from aging sensors. The technique improves battery management system reliability and safety by considering sensor aging errors when determining battery model parameters. This reduces errors in the estimated battery state of charge. The method involves acquiring battery voltage and current data, calculating sensor aging error factors, and accounting for those factors when determining battery model parameters.

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Monitoring battery cell failure in parked electric vehicles to prevent safety issues when the battery management system is dormant. The system has a separate battery sampling module that wakes up the main controller if it detects abnormal battery pack state. The module collects pack status when parked and sends to the controller when awakened. This allows monitoring battery health even when the main controller is dormant.

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A battery management system for electric vehicles that reduces size and cost compared to traditional designs. The system uses a single integrated module instead of separate front-end and control modules. The integrated module includes bridge chips to connect the front-end and control sections. This allows the front-end to directly transmit battery data to the control chip. The integration reduces component count and size while eliminating the need for separate interconnects. The system also enables real-time adjustment of charging and discharging parameters based on battery state to optimize performance and longevity.

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Battery management system for vehicles that allows continuous monitoring of battery health even when the vehicle is not in use. The system has a separate power source that keeps the battery management module, gateway, and terminal powered when the vehicle is off. This allows the module to continuously monitor battery cells and detect faults, unlike a centralized system that relies on vehicle power. The gateway forwards any battery faults to the vehicle terminal.

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Battery management system for vehicles that reduces cost and space requirements compared to separate 12V and 48V battery packs. The system has a fused battery pack with a single shared battery, where each battery cell has an internal DC-DC converter. This allows independent voltage control and power balancing between cells. It prevents imbalance issues and improves efficiency compared to directly connecting the cells.

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Preheating electric vehicle batteries before charging in cold weather to improve charging efficiency and battery life. The method involves warming the battery pack using onboard heating elements when the vehicle is parked. The vehicle can receive a battery preheating instruction from the driver's terminal. The preheating is done prior to connecting the vehicle to a charging station. This prevents battery degradation and long charging times in cold weather.

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A data processing system for electric vehicles that continuously updates the reference curves pre-stored in the battery management system (BMS) to improve battery life. The system involves sending primary battery data from the vehicle BMS to the cloud, which generates secondary data based on the vehicle ID. The BMS receives this secondary data and updates the stored reference curves accordingly. This allows the BMS to accurately estimate battery parameters using the updated curves, which is beneficial for managing battery health.

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