Battery Circuit Switching Serial Parallel Connections

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Solution Overview

Problem

Energy battery packs face reduced capacity and shortened service life due to performance differences among cells, leading to uneven charging and potential damage during charging and discharging, especially when cells are charged in series.

Innovation Solution

A circuit with cell connection conversion functions, utilizing metal oxide semiconductor field effect transistors (MOSFETs) and a master control unit to switch between serial and parallel connections of cell groups, allowing for intelligent charging based on temperature and voltage differences, and enabling multi-voltage outputs to adapt to various applications.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If cells are charged in series, then charging speed is improved, but cell performance differences accumulate causing reduced capacity and shortened service life

Engineering Contradiction:
Improvecharging speedVSAvoidservice life
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent implements dynamic switching between series and parallel charging connections based on real-time cell state monitoring. The master control unit adjusts the connection configuration during charging to balance cell voltages and prevent performance differences from accumulating, thereby maintaining both high charging speed and long service life

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the electrical connection parameters (series/parallel configuration) based on cell voltage and temperature parameters. By monitoring cell states and adjusting connection modes dynamically, the system optimizes charging speed while preventing capacity loss and extending service life

Inventive Principle:
Principle #35Parameter changes

2Use of energy by moving object

If cells are charged in series, then charging efficiency is improved, but individual cells may be undercharged due to performance differences

Engineering Contradiction:
Improvecharging efficiencyVSAvoidcharging balance
Core Design Contradiction:
Use of energy by moving objectVSManufacturing precision

Solution Approach 1:

The patent employs a master control unit that continuously monitors cell voltages and temperatures, providing feedback to adjust the charging connection configuration. This feedback mechanism ensures that cells with different performance levels are charged appropriately, maintaining both high charging efficiency and balanced charging across all cells

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system dynamically switches between series and parallel connections based on real-time cell state feedback. When cell voltage differences exceed a threshold, the system transitions to parallel connection to balance charging, then returns to series connection for efficient charging, ensuring both efficiency and charging balance

Inventive Principle:
Principle #15Dynamics

3Device complexity

If battery pack voltage is fixed, then system simplicity is maintained, but adaptability to different applications is reduced

Engineering Contradiction:
Improvesystem simplicityVSAvoidvoltage adaptation
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The patent makes the battery pack universally adaptable to different voltage requirements by implementing switchable series/parallel connections. The same battery pack can output different voltages (e.g., 18V, 36V, 54V) by reconfiguring cell group connections, eliminating the need for multiple dedicated battery packs for different voltage applications

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

Solution Approach 2:

The battery pack uses dynamic connection reconfiguration to adapt its output voltage based on application requirements. The master control unit switches between series and parallel connections of cell groups to provide different voltage levels, maintaining system simplicity while achieving multi-voltage adaptability

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP4102680A1Circuit having balanced charging and cell connection conversion functions
Publication Date: 2022.12.14 TECHTRONIC CORDLESS GP
  • EP4102680A1 patent drawingFigure 1~2A
  • EP4102680A1 patent drawingFigure 2B
  • EP4102680A1 patent drawingFigure 3A

AI summary

The present invention discloses a circuit having balanced charging and cell connection conversion functions. The circuit according to the present invention includes n cell groups, n-1 third switching circuits, and a master control unit, where n is an integer greater than 1. Each of the cell groups includes a first switching circuit, a cell, and a second switching circuit that are connected in series in sequence. The first switching circuit is connected between a positive wire and a positive terminal of the cell. The second switching circuit is connected between a negative wire and a negative terminal of the cell. Each of the third switching circuits is connected between a positive terminal and a negative terminal of two cells adjacent to each other. The master control unit controls turn-on/turn-off of the first switching circuits, the second switching circuits, and the third switching circuits by sending a control signal on a control bus, to enable switching of a serial/parallel connection of the n cell groups.