Battery Pack Contact Defect Detection Through Cell Voltage Deviation

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Solution Overview

Problem

Existing battery management systems struggle to detect contact defects in battery modules without disassembling the battery pack, leading to voltage imbalances and performance deterioration, which requires costly and time-consuming manual intervention.

Innovation Solution

A battery management system with slave and master managers that detect contact defects by analyzing voltage deviations between battery cells, allowing for non-invasive identification of defective modules using a cell balancer system that performs balancing operations and instantaneous discharges to identify contact defects.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a contact defect is detected using an OCV-IR test device after disassembling the battery pack, then the detection accuracy is improved, but the operational time is increased and productivity is reduced

Engineering Contradiction:
Improvecontact defect detection accuracyVSAvoidbattery pack operational time
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The system performs preliminary detection of contact defects during normal battery pack operation using voltage deviation analysis. The master manager continuously monitors cell voltages and identifies modules with contact defects before disassembly is required, enabling proactive maintenance while the battery pack remains assembled and operational.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent replaces the mechanical disassembly process with an electrical detection method. Instead of physically taking apart the battery pack to access modules for OCV-IR testing, the system uses electrical voltage measurements through existing connections to detect contact defects, eliminating the need for mechanical intervention.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Difficulty of detecting and measuring

If the battery pack is disassembled to detect contact defects, then the detection capability is improved, but the time cost and operational disruption are increased

Engineering Contradiction:
Improvecontact defect detectabilityVSAvoiddisassembly and reinstallation time
Core Design Contradiction:
Difficulty of detecting and measuringVSLoss of time

Solution Approach 1:

The battery management system performs self-diagnosis by continuously monitoring its own operational parameters (cell voltages) to detect contact defects. The master manager analyzes voltage deviations among slave managers to identify defective modules without requiring external intervention or disassembly, enabling the system to monitor itself autonomously during normal operation.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent uses voltage deviation as an intermediary indicator to detect contact defects. Instead of directly measuring contact resistance which would require disassembly, the system measures voltage deviations across battery modules, which serve as indirect evidence of contact defects. This intermediary measurement approach enables detection through existing electrical connections without mechanical access.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If voltage imbalance is caused by contact defects, then the reliability of individual modules is reduced, but the complexity of detection system is increased

Engineering Contradiction:
Improvebattery module performanceVSAvoiddetection system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The master manager serves multiple functions: it controls slave managers for cell balancing operations and simultaneously detects contact defects by analyzing voltage deviations. This multi-functionality eliminates the need for separate detection hardware, reducing system complexity while maintaining comprehensive monitoring capabilities for both performance optimization and defect detection.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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

Enables the detection of contact defects within battery modules without disassembly, maintaining pack operation and reducing downtime and costs associated with manual disassembly.

Implementation Method 1

configured to detect a battery module having a contact defect therein using a voltage deviation that is a difference between a maximum value and a minimum value of the cell voltages

Methodology Applied
Scientific EffectVoltage deviation analysis: Ohm's Law

Implementation Method 2

slave managers corresponding respectively to a plurality of battery modules, and configured to uniformly adjust cell voltages of a plurality of battery cells of the respective battery modules

Methodology Applied
Scientific EffectElectrical current flow: Conduction (electrical)

Data Source

PatentEP4614670A1Battery management system, battery pack including the same, and method of detecting contact defect module using the same
Publication Date: 2025.09.10 SAMSUNG SDI CO LTD
  • EP4614670A1 patent drawingFigure 1
  • EP4614670A1 patent drawingFigure 2
  • EP4614670A1 patent drawingFigure 3

AI summary

Provided are a battery management system and a battery pack including the same. The battery management system includes a plurality of slave managers provided to correspond to a plurality of battery modules, and configured to uniformly adjust cell voltages of a plurality of battery cells of respective battery modules, a master manager configured to detect a battery module having a contact defect therein among the battery modules as a defective module using a voltage deviation that is a difference between a maximum value and a minimum value of the cell voltages, and a data transmitter configured to electrically connect the master manager and the slave managers to enable data exchange.