Foldable Power Architecture With Battery Isolation Balancing

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Solution Overview

Problem

In foldable electronic devices, the long power transmission paths cause significant impedance losses, leading to reduced reliability of the rotation mechanism and flexible screen due to the need for wider traces, which compromises the structural integrity and support for the flexible screen.

Innovation Solution

Implementing separate power management modules in each foldable portion and a second foldable portion, with an isolation circuit to perform voltage balancing on the two batteries, and a second battery pack, and a second power management module in a second foldable portion, and an isolation circuit connected to both batteries to balance voltages and reduce trace impedance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If the trace width in the power transmission path is increased to reduce path impedance loss, then the power transmission efficiency is improved, but the reliability of the rotation mechanism and flexible screen deteriorates

Engineering Contradiction:
Improvepower transmission lossVSAvoidreliability of rotation mechanism and flexible screen
Core Design Contradiction:
Loss of energyVSReliability

Solution Approach 1:

The patent divides the power transmission system into two independent segments: one power management module is disposed in the first foldable portion and another in the second foldable portion. Each module independently manages power transmission to its respective portion, thereby shortening the power transmission path and eliminating the need to increase trace width, thus preserving the reliability of the rotation mechanism and flexible screen while reducing impedance loss.

Inventive Principle:
Principle #1Segmentation

2Loss of energy

If separate power management modules are implemented in each foldable portion to shorten power transmission path, then the power transmission efficiency is improved, but the device complexity increases

Engineering Contradiction:
Improvetrace impedance lossVSAvoidpower management structure complexity
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

The power management system is segmented into two independent modules distributed across the first and second foldable portions. Each module handles power management locally, reducing transmission path impedance. The isolation circuit further segments the battery system to prevent mutual charging, managing complexity through functional decomposition.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Each foldable portion is equipped with its own power management module, enabling local power management. This local quality approach allows each portion to independently regulate power transmission, reducing overall system complexity by distributing management functions rather than requiring a centralized complex system.

Inventive Principle:
Principle #3Local quality

3Quantity of substance

If batteries are disposed in each foldable portion to extend battery life, then the total battery capacity is increased, but the voltage imbalance and mutual charging current increase

Engineering Contradiction:
Improvetotal battery capacityVSAvoidvoltage imbalance and mutual charging current
Core Design Contradiction:
Quantity of substanceVSObject-generated harmful factors

Solution Approach 1:

An isolation circuit is introduced as an intermediary between the batteries in the first and second foldable portions. This isolation circuit prevents direct electrical connection between the batteries, thereby eliminating mutual charging current and voltage imbalance issues while preserving the extended battery life benefit of having distributed battery capacity.

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP4459424B1Folding electronic device
Publication Date: 2026.03.04 HONOR DEVICE CO LTD
  • EP4459424B1 patent drawingFigure 1
  • EP4459424B1 patent drawingFigure 2~3
  • EP4459424B1 patent drawingFigure 4

AI summary

Embodiments of this application provide a foldable electronic device, and are applied to the field of electronic technologies. A first power management module, a first load, and a first battery pack are disposed in a first foldable portion in the foldable electronic device. A second power management module, a second load, and a second battery pack are disposed in a second foldable portion in the foldable electronic device. The first power management module controls the first battery pack to supply power to the first load, and the second power management module controls the second battery pack to supply power to the second load. The foldable electronic device further includes an isolation circuit, and the isolation circuit may perform voltage balancing on voltages of two connected batteries. In this way, a power transmission path existing when the first battery pack supplies power to the first load and a power transmission path existing when the second battery pack supplies power to the second load may be shortened. Correspondingly, reliability of a rotation mechanism and a flexible screen may be improved. In addition, the isolation circuit may reduce a voltage difference between the two connected batteries, to improve safety and reliability of the foldable electronic device.