Battery Internal Resistance Offset Correction for Aging

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Solution Overview

Problem

Existing battery monitoring methods fail to accurately predict battery power-delivery performance under varying load conditions and do not account for battery aging, leading to under-utilization and the need for frequent testing.

Innovation Solution

A method that models and dynamically updates internal resistance based on battery operating parameters, using a calibration discharge cycle to maintain prediction accuracy as the battery ages, allowing for user-defined power levels and targets to optimize battery utilization.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If battery status indicators are based on state of charge or voltage, then the battery system provides simple status indication, but it fails to accurately predict power-delivery performance under varying load conditions

Engineering Contradiction:
Improvesimplicity of status indicationVSAvoidaccuracy of power-deliction performance prediction
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The patent transitions from using simple voltage or state-of-charge parameters to using internal resistance as the key parameter for predicting power-delivery performance. Internal resistance is calculated from measured voltage and current values during discharge cycles, and this parameter directly correlates with the battery's ability to deliver power under varying load conditions.

Inventive Principle:
Principle #35Parameter changes

2Stability of the object's composition

If battery systems rely on a-priori testing and standardized load tests, then the testing process is standardized and reproducible, but the system does not provide dynamic updates to account for battery aging and behavior changes

Engineering Contradiction:
Improvestandardization of testingVSAvoiddynamic update capability for battery aging
Core Design Contradiction:
Stability of the object's compositionVSAdaptability or versatility

Solution Approach 1:

The battery management system performs self-calibration by automatically comparing measured internal resistance values against expected values from discharge cycle maps. The system generates correction factors autonomously and uses these to adjust future predictions, eliminating the need for manual re-testing while adapting to battery aging.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The system continuously monitors actual battery performance during discharge cycles, compares measured internal resistance against predicted values, and uses the difference (correction factor) to refine future predictions. This closed-loop feedback mechanism enables dynamic adaptation to battery aging while maintaining standardized testing procedures.

Inventive Principle:
Principle #23Feedback

3Device complexity

If battery systems use fixed discharge cycle maps without correction, then the prediction model is simple to implement, but prediction accuracy deteriorates as the battery ages

Engineering Contradiction:
Improvesimplicity of prediction modelVSAvoidprediction accuracy over time
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The system pre-generates discharge cycle maps containing expected internal resistance values for various states of charge during discharge. These maps serve as lookup tables that provide quick predictions without complex real-time calculations, maintaining simplicity while enabling accurate predictions when combined with correction factors.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP2672562B1Systems and methods for predicting battery power-delivery performance
Publication Date: 2018.08.08 GENERAL ELECTRIC CO
  • EP2672562B1 patent drawingFigure 1
  • EP2672562B1 patent drawingFigure 2
  • EP2672562B1 patent drawingFigure 3

AI summary

Battery management systems and methods related to predicting power-delivery performance are provided. In one embodiment, a method for predicting power-delivery performance for a battery (102) includes retrieving a plurality of battery operating parameters (106, 108, 110, 112) for a selected discharge cycle, calculating an offset (114) indicative of a difference between a modeled internal resistance (118) of the battery (102) and an observed internal resistance (116) generated from a calibration discharge cycle of the battery prior to the selected discharge cycle, and outputting a battery power-delivery performance prediction (128) based on an offset-corrected internal resistance indicative of a difference between a modeled internal resistance (118) based on the plurality of battery operating parameters (106, 108, 110, 112) for the selected discharge cycle and the offset (114).