Battery Degradation Estimation Separating Storage and Cycle Effects
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Solution Overview
Problem
Existing methods for estimating battery degradation degree, such as those based on the square root of total traveling distance, result in significant errors due to the neglect of storage degradation and cycle degradation, which progress differently over time and through charge/discharge cycles.
Innovation Solution
A battery degradation degree estimation device that separates and estimates storage degradation and cycle degradation, using sensors to detect output characteristics and integrate values over fixed periods, and calculates future degradation based on established characteristics, allowing for accurate prediction of remaining battery life.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If battery degradation is estimated based on square root of total traveling distance, then estimation simplicity is maintained, but estimation accuracy deteriorates due to neglecting storage and cycle degradation differences
Solution Approach 1:
The patent segments battery degradation into three distinct components: storage degradation (progresses with time regardless of usage), cycle degradation (progresses with charge/discharge cycles), and a combined model that integrates both. This segmentation allows each degradation type to be calculated separately using appropriate parameters (time for storage, cycle count for cycle degradation) and then summed to obtain total degradation, thereby improving accuracy while maintaining reasonable complexity
Solution Approach 2:
The patent changes the parameters used for degradation estimation from a single parameter (traveling distance) to multiple parameters including storage time, cycle count, and their respective degradation characteristics. By introducing different parameters for different degradation mechanisms and changing how degradation is modeled (from distance-based to time/cycle-based components), the estimation accuracy is significantly improved
2Measurement precision
If storage degradation and cycle degradation are separated and estimated independently, then degradation estimation accuracy is improved, but calculation complexity increases
Solution Approach 1:
The patent divides total degradation into separable components (storage degradation and cycle degradation) that can be calculated independently using different formulas and parameters. Storage degradation is calculated based on time elapsed, while cycle degradation is calculated based on charge/discharge cycle count. This segmentation allows each component to be computed separately and then combined, improving accuracy without requiring complex integrated modeling
Solution Approach 2:
After separately calculating storage degradation and cycle degradation using their respective models, the patent merges these independent calculations by summing them to obtain the total battery degradation. This combining approach maintains the simplicity of individual calculations while achieving accurate overall estimation through the superposition of degradation components
Data Source
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AI summary
A battery degradation degree estimation device includes a total degradation degree detection unit 110 configured to detect a present total degradation degree of a battery, a cycle degradation estimation unit 120 configured to estimate a future cycle degradation degree due to charge/discharge of the battery, a storage degradation estimation unit 130 configured to estimate a future storage degradation degree over time inside the battery, and a battery degradation estimation unit 140 configured to estimate a future battery degradation degree on the basis of the present total degradation degree, the future cycle degradation degree and the future storage degradation degree.