Battery SOH Estimation from Charging Data and Full-Spectrum Analysis

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing methods for estimating the state of health (SOH) of batteries are inefficient and require significant energy and time, and they may miss important parameters due to limited frequency analysis, especially in non-equilibrium states.

Innovation Solution

A system and method that utilize the generalized fluctuation-dissipation theorem (GFDT) to derive SOH parameters from current and voltage fluctuations during battery charging, eliminating the need for repetitive frequency measurements and additional equipment, and allowing full-spectrum analysis of frequency domains.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If traditional frequency domain analysis methods are used for SOH estimation, then measurement precision can be improved, but energy consumption and time required increase significantly

Engineering Contradiction:

ImproveSOH estimation accuracyVSAvoidEnergy consumption

Core Design Contradiction:

Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The patent applies preliminary action by pre-calculating and storing frequency response functions during battery manufacturing or initial characterization. These pre-computed functions are then used during normal operation to estimate SOH without requiring repetitive frequency sweeping, thereby reducing real-time energy consumption while maintaining estimation accuracy.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system uses the battery's own voltage and current measurements during normal charging operations to extract frequency response characteristics. By leveraging the battery's self-generated data rather than requiring external test equipment or separate measurement campaigns, the method reduces additional energy consumption while obtaining comprehensive frequency domain information.

Inventive Principle:

Principle #25Self-service

2Measurement precision

If traditional frequency domain analysis methods are used for SOH estimation, then measurement precision can be improved, but time required increases significantly

Engineering Contradiction:

ImproveSOH estimation accuracyVSAvoidTime required

Core Design Contradiction:

Measurement precisionVSLoss of time

Solution Approach 1:

Frequency response functions are pre-computed during battery manufacturing or initial characterization and stored for later use. During normal operation, these pre-stored functions enable rapid SOH estimation without requiring time-consuming frequency sweeping procedures, thus significantly reducing measurement time while maintaining precision.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent continuously monitors voltage and current during normal battery charging operations and extracts frequency response information from these ongoing measurements. This continuous data collection approach eliminates the need for separate dedicated measurement campaigns, making time efficient by utilizing existing operational time for dual purposes.

Inventive Principle:

Principle #20Continuity of useful action

3Productivity

If limited frequency analysis is performed, then energy and time consumption are reduced, but important parameters may be missed due to incomplete frequency coverage

Engineering Contradiction:

ImproveMeasurement efficiencyVSAvoidParameter completeness

Core Design Contradiction:

ProductivityVSLoss of information

Solution Approach 1:

The patent uses a single measurement approach during normal charging operations to simultaneously obtain voltage, current, and frequency response functions across the full spectrum. This multi-functional measurement strategy ensures that no important parameters are missed while maintaining high efficiency, as one measurement process serves multiple analytical purposes.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The method transforms time-domain voltage and current measurements into frequency-domain representations through mathematical transformation (Fourier transform). This dimensional transformation enables comprehensive frequency analysis to be performed on data already collected during normal operation, effectively adding frequency domain information without requiring separate measurement campaigns.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach provides accurate and efficient SOH estimation by leveraging existing charging data, reducing energy consumption and time, while minimizing the risk of missing important parameters due to battery aging.

Implementation Method 1

the generalized fluctuation-dissipation theorem may be applied to the measured current and voltage to obtain the SOH parameters

Methodology Applied

Scientific EffectGeneralized fluctuation-dissipation theorem:

Data Source

PatentUS20250327876A1System for estimating the state of health of battery, system and method for deriving parameters therefor

Publication Date: 2025.10.23 HEI INC

AI summary

Systems and methods for estimating the state of health (SOH) of a battery are provided. The system includes a database, a parameter processing module, and an SOH estimation module. The database stores current and voltage data measured at a specific sampling rate during battery charging. The parameter processing module obtains response functions in the frequency domain, differential capacity, and differential voltage based on the stored current and voltage data and uses them to obtain parameters for SOH estimation. The SOH estimation module uses some or all the obtained parameters to estimate the SOH.