Switchable Battery Pack Circuit for Multi-Voltage Charging

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Solution Overview

Problem

Existing battery packs are limited to a single charging voltage, requiring voltage boosters for compatibility with different charging platforms, which increases costs and is inconvenient for daily use.

Innovation Solution

A battery pack design with a switch device that allows battery cell units to be connected in series or separately, enabling compatibility with multiple charging voltages by selectively connecting or disconnecting the series circuit, eliminating the need for voltage boosters.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a battery pack is designed for a single charging voltage, then the charging system is simple and reliable, but the battery pack cannot be compatible with different charging platforms

Engineering Contradiction:
Improvecompatibility with different charging platformsVSAvoidcharging system complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The battery pack uses a switch device to dynamically reconfigure the connection state of battery cell units, transitioning between series connection (for higher voltage compatibility) and separate connection (for lower voltage compatibility). This dynamic reconfiguration enables the battery pack to adapt to different charging platforms without requiring multiple fixed configurations or additional voltage conversion equipment.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The battery pack divides the battery cells into multiple independently controllable battery cell units. Each unit can be selectively connected or disconnected from the series circuit through the switch device. This segmentation allows flexible configuration of the overall battery voltage by controlling which units are active in the series connection, enabling compatibility with both 400V and 800V charging platforms.

Inventive Principle:
Principle #1Segmentation

2Adaptability or versatility

If a voltage booster is added to enable compatibility with different charging voltages, then the battery pack can charge on multiple platforms, but the cost increases

Engineering Contradiction:
Improvecompatibility with different charging platformsVSAvoidsystem cost
Core Design Contradiction:
Adaptability or versatilityVSQuantity of substance

Solution Approach 1:

The invention extracts and removes the voltage booster component from the system. Instead of adding a voltage booster to enable multi-platform charging, the patent uses the inherent series connection capability of battery cell units combined with a switch device to directly provide different voltage outputs. This eliminates the need for expensive voltage conversion equipment while maintaining compatibility with both 400V and 800V charging platforms.

Inventive Principle:
Principle #2Taking out (Extraction)

3Adaptability or versatility

If a voltage booster is used to adapt to different charging voltages, then the battery pack can charge on multiple platforms, but the system becomes inconvenient for daily use

Engineering Contradiction:
Improvecompatibility with different charging platformsVSAvoidusability convenience
Core Design Contradiction:
Adaptability or versatilityVSEase of operation

Solution Approach 1:

The battery pack performs self-service by automatically or manually reconfiguring its internal circuitry through the switch device to match the charging platform voltage. This eliminates the need for external voltage boosters and the complex operations they would require. The user simply connects to the charging platform, and the battery pack's control system manages the switching between series connection modes to achieve compatibility, making the process as convenient as traditional single-voltage charging.

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP4579870A1Battery pack and electric apparatus
Publication Date: 2025.07.02 XIAOMI EV TECH CO LTD
  • EP4579870A1 patent drawingFigure 1~2
  • EP4579870A1 patent drawingFigure 3~4
  • EP4579870A1 patent drawingFigure 5

AI summary

A battery pack includes a battery pack case, a switch device (10), and a plurality of battery cell units. The plurality of battery cell units are arranged in the battery pack case, a positive electrode of each of the battery cell units is configured to be electrically connected to a positive terminal of the power distribution unit, and a negative electrode of each of the battery cell units is configured to be electrically connected to a negative terminal of the power distribution unit. In addition, the plurality of battery cell units are sequentially arranged in a series circuit of the battery pack, and two ends of the series circuit are respectively connected to the positive terminal and the negative terminal of the power distribution unit. The switch device (10) is arranged in the series circuit for connecting or disconnecting the series circuit.