Battery Pack Diagnostic Circuit Branching for Cell Monitoring

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional battery packs face difficulties in acquiring information from individual battery cells directly, leading to complex structures and increased costs, as well as challenges in diagnosing failures within the battery management unit without complicating the system.

Innovation Solution

A battery pack design that includes a diagnostic circuit branched from the information transfer circuit, allowing direct access to information from the battery cells without relying on the battery management unit, with separate power and communication lines for the cell monitoring unit and a diagnostic circuit extended to the outer surface for easy access.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of information

If a connector for external connection is formed to directly acquire information from battery cells, then information accessibility is improved, but device complexity increases

Engineering Contradiction:
Improveinformation accessibilityVSAvoidstructure complexity
Core Design Contradiction:
Loss of informationVSDevice complexity

Solution Approach 1:

The diagnostic circuit is extracted as a separate branch from the information transfer circuit, allowing direct access to battery cell information independent of the battery management unit. This extraction enables information acquisition without passing through the BMU, solving the problem of information accessibility while maintaining a relatively simple integrated structure rather than adding completely separate connectors.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The information transfer circuit serves dual functions: normal operation (transferring information to the battery management unit) and diagnostic operation (providing direct access through the branched diagnostic circuit). This multi-functionality eliminates the need for separate dedicated connectors for diagnostics, reducing overall device complexity while maintaining information accessibility.

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

2Device complexity

If the battery management unit is used to acquire information from battery cells, then system structure is simplified, but reliability decreases due to single point of failure

Engineering Contradiction:
Improvesystem structureVSAvoidfailure diagnosis capability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The diagnostic circuit acts as an intermediary pathway that bypasses the battery management unit for information acquisition. When the BMU fails, this intermediary circuit allows direct access to battery cell information, providing redundancy and improving reliability without complicating the overall system structure.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The information transfer system is segmented into two independent pathways: the main information transfer circuit for normal operation and the branched diagnostic circuit for direct access. This segmentation creates functional independence, allowing the diagnostic pathway to operate even when the main pathway through the BMU fails.

Inventive Principle:
Principle #1Segmentation

3Reliability

If separate power source lines are provided for battery management unit and cell monitoring unit, then reliability is improved, but device complexity increases

Engineering Contradiction:
Improvepower supply reliabilityVSAvoidcircuit complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The power supply system is segmented into separate power source lines for the battery management unit and cell monitoring unit. This segmentation ensures that power failures or electrical issues in one unit do not affect the other, improving reliability while maintaining clear circuit organization that manages complexity.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP2866326B1Battery pack
Publication Date: 2018.10.10 MITSUBISHI MOTORS CORP
  • EP2866326B1 patent drawingFigure 1
  • EP2866326B1 patent drawingFigure 2~3
  • EP2866326B1 patent drawingFigure 4~5

AI summary

A battery pack for housing plural secondary batteries inside a case includes a battery management unit for managing states of the plural secondary batteries, an information transfer circuit which is connected to the battery management unit and transfers information about the secondary batteries to the battery management unit, and a diagnostic circuit which is branched and formed from the information transfer circuit and is extended to an outer surface of the case.