Battery Cell Voltage Balancing via Flyback Transformer Segmentation

Solution Overview

Problem

Battery packs face challenges in balancing voltage across cells, leading to reduced capacity utilization due to charge imbalances caused by manufacturing tolerances and environmental differences, resulting in higher current demands and increased peak current requirements.

Innovation Solution

The method involves actively balancing charge within the battery pack by discharging cells through a first current path and charging specific cells via flyback transformers in a secondary current path, controlling the timing of charging to distribute current more efficiently and reduce peak demand.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If charge is balanced by charging all battery cells simultaneously, then battery capacity utilization is improved, but peak current demand increases

Engineering Contradiction:

Improvebattery capacity utilizationVSAvoidpeak current demand

Core Design Contradiction:

Quantity of substanceVSPower

Solution Approach 1:

The patent segments the battery cells into different groups based on their charge states and charges them at different times. Instead of charging all cells simultaneously, the system divides cells into first and second groups, charging the first group during a first time period and the second group during a second time period, thereby distributing the current demand over time and reducing peak current requirements

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent implements periodic charging actions by alternating between charging different groups of battery cells in different time periods. The system performs charging operations in a sequential manner across multiple cycles, where first group cells are charged during first time periods and second group cells are charged during second time periods, creating a periodic pattern that smooths current demand

Inventive Principle:

Principle #19Periodic action

2Quantity of substance

If higher current capacity components are used to balance charge, then battery capacity utilization is improved, but device complexity and cost increase

Engineering Contradiction:

Improvebattery capacity utilizationVSAvoidcurrent capacity requirements

Core Design Contradiction:

Quantity of substanceVSDevice complexity

Solution Approach 1:

The patent segments the battery cells into different groups based on their charge states and charges them at different times. Instead of charging all cells simultaneously, the system divides cells into first and second groups, charging the first group during a first time period and the second group during a second time period, thereby distributing the current demand over time and reducing peak current requirements

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent implements periodic charging actions by alternating between charging different groups of battery cells in different time periods. The system performs charging operations in a sequential manner across multiple cycles, where first group cells are charged during first time periods and second group cells are charged during second time periods, creating a periodic pattern that smooths current demand

Inventive Principle:

Principle #19Periodic action

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 increases the usable capacity of the battery pack while limiting current flow, reducing peak current demand, electrical noise, and voltage ripple, thereby optimizing battery performance.

Implementation Method 1

providing charge to a first battery cell via a first flyback transformer during said second battery discharge cycle, said flyback transformer in a second current path; providing charge to a second battery cell via a second flyback transformer during said second battery discharge cycle

Methodology Applied

Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentUS8541979B2System and method for balancing voltage of individual battery cells within a battery pack

Publication Date: 2013.09.24 A123 SYSTEMS LLC

AI summary

Systems and methods for actively balancing battery cells are disclosed. In one example, a charge is supplied to different battery cells at different times during a battery discharge cycle. The method may reduce instantaneous current draw within a battery pack.