Battery SOH Estimation Using In-Service Current and Voltage Models
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Solution Overview
Problem
Current battery state of health detection methods cannot accurately monitor battery performance attenuation in an in-service state, disrupting power supply to devices like data center devices, optical communications devices, and base stations.
Innovation Solution
An apparatus and method that measure current and voltage values at different times, selecting between first and second model algorithms based on threshold comparisons, calculating battery open circuit voltage and state of charge, and determining battery capacity differences to estimate battery state of health using temperature and capacity modifications.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If battery state of health is detected using checking charge/discharge manner, then battery retention capacity can be accurately measured, but the apparatus cannot normally supply power for load and service is greatly impacted
Solution Approach 1:
The battery management system performs self-diagnosis by utilizing the battery's own charging/discharging process data to calculate state of health parameters, eliminating the need for external testing equipment and out-of-service conditions. The system continuously monitors voltage, current, and temperature during normal operation to compute retention capacity and state of health without interrupting power supply to the load.
2Measurement precision
If battery state of health is detected in out-of-service state, then accurate capacity measurement can be achieved, but service continuity is disrupted
Solution Approach 1:
The patent implements continuous battery monitoring during normal service operation by integrating state of health detection into the ongoing charging and discharging cycles. The system continuously acquires voltage, current, and temperature data and performs real-time calculations of retention capacity and state of health, ensuring uninterrupted power supply to the load while maintaining accurate battery assessment.
3Measurement precision
If multiple model algorithms are used for different current conditions, then battery state of health detection accuracy is improved, but device complexity increases
Solution Approach 1:
The patent employs multiple detection models (first model for high current conditions, second model for low current conditions) that are selectively applied based on the measured current magnitude. The control unit compares the absolute value of detected current against a threshold and dynamically switches between models, optimizing detection accuracy for different operational states without requiring a single overly complex algorithm.
Data Source
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AI summary
The present invention provides a method for detecting a battery state of health. In this method, a current and a voltage are measured twice in a period of time; corresponding model algorithms are selected according to the measured current values; corresponding battery open circuit voltage values and battery state of charge values at a start time and an end time of the period are obtained based on the model algorithms; a battery capacity difference that indicates a present battery retention capacity and a battery capacity difference that indicates a future battery retention capacity are calculated; and a battery state of health value is calculated when impact of a measured battery temperature value is considered. Embodiments of the present invention further provide an apparatus for detecting a battery state of health. In the embodiments of the present invention, a battery state of health can be detected in an in-service state, and battery aging can be monitored accurately and in a timely manner, so as to ensure that a device normally supplies power for a load, and avoid affecting a service.