Battery OCV-SOC Curve Estimation Through Parallel Cell Testing
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Solution Overview
Problem
The existing methods for generating an OCV-SOC curve for battery cells are time-consuming and inefficient, requiring extensive testing at multiple points and temperatures, which prolongs the characterization process.
Innovation Solution
A method and apparatus for concurrently testing multiple battery cells, dividing the testing points among the cells, and merging their OCV-SOC curves to generate a single curve, reducing the number of testing points and temperatures needed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If sequential testing of battery cells at multiple SOC points is performed, then measurement precision of OCV-SOC curve is improved, but loss of time increases significantly
Solution Approach 1:
The patent divides the testing process into multiple independent parallel testing lines, where each battery cell is tested at different SOC points simultaneously. This segmentation allows the total characterization time to be reduced from testing all points sequentially to testing multiple points concurrently, directly resolving the time-loss issue while maintaining measurement precision through proper distribution of testing points across multiple cells.
Solution Approach 2:
The patent introduces a new dimension of parallelism by testing multiple battery cells simultaneously at different SOC points. Instead of moving through SOC points one after another in a single dimension, the system distributes testing points across multiple cells in parallel, effectively adding a temporal dimension to the testing process and reducing overall characterization time while maintaining curve accuracy.
2Productivity
If multiple battery cells are tested concurrently at alternate testing points, then productivity is improved, but device complexity increases
Solution Approach 1:
The testing system is segmented into multiple independent testing lines, each capable of operating autonomously at different SOC points. This segmentation allows concurrent testing of multiple battery cells without requiring complex inter-cell coordination, as each testing line functions independently. The control system manages multiple simple testing lines rather than one complex sequential process, improving productivity while keeping individual testing unit complexity low.
Solution Approach 2:
The patent employs universal testing equipment that can be configured to test battery cells at different SOC points. The same testing apparatus and measurement systems are used across multiple parallel testing lines, allowing the system to handle various testing scenarios with standardized equipment. This multi-functionality approach improves productivity through parallel testing while avoiding the need for specialized complex equipment for each testing point.
3Manufacturing precision
If more testing points are distributed among multiple battery cells, then manufacturing precision of OCV-SOC curve is improved, but loss of time should be reduced, creating a contradiction
Solution Approach 1:
The patent segments the total number of testing points across multiple battery cells, assigning different SOC points to different cells for concurrent testing. This segmentation enables the system to maintain high manufacturing precision by adequately sampling the OCV-SOC relationship across the full SOC range while reducing testing duration through parallel execution. Each cell is tested at a sufficient number of points to ensure curve precision, but the overall process is accelerated by distributing points across multiple cells simultaneously.
Solution Approach 2:
The patent changes the parameter of testing configuration from sequential single-cell testing to parallel multi-cell testing with distributed SOC points. By altering how testing points are allocated and executed—distributing them across multiple cells that test concurrently rather than sequentially—the system achieves both high curve precision (through adequate sampling) and reduced testing time (through parallelism), resolving the contradiction between precision and time loss.
Data Source
AI summary
A method includes applying a preliminary discharge/charge cycle to a plurality of battery cells to obtain an initial capacity of each battery cell, applying multiple small current discharge/charge cycles to the plurality of battery cells to minimize initial voltage deviations of the plurality of battery cells, configuring a first battery cell to be tested at a plurality of first testing points, configuring a second battery cell to be tested at a plurality of second testing points, and configuring a third battery cell to be tested at a plurality of third testing points, wherein the first battery cell, the second battery cell and the third battery cell are tested concurrently for generating an OCV-SOC curve, and the plurality of first testing points, the plurality of second testing points and the plurality of third testing points are arranged in an alternate manner.