High-Voltage Battery Pack Disconnection Detection
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Solution Overview
Problem
Current battery packs with output voltages below 30V are insufficient for powering large-power electric tools, and there is no safe charging assembly or control method available for higher voltage outputs, limiting the development of wireless electric tools.
Innovation Solution
A battery pack with a minimum 56V output voltage, featuring series connection units, a voltage detecting module, and a battery control module that includes a disconnection detecting module to determine cell disconnection based on voltage, time, internal resistance, and current, ensuring safe charging and operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If battery packs use series connection of parallel battery cells to achieve high voltage (56V or above), then the power output capability is improved to drive large-power electric tools, but the risk of cell disconnection and charging safety issues increases
Solution Approach 1:
The patent implements preliminary disconnection detection by monitoring voltage changes across series connection units before charging operations proceed. The control module detects voltage differences between adjacent series connection units and identifies potential disconnections in advance, preventing unsafe charging conditions from developing. This preliminary detection mechanism ensures reliability is maintained while enabling high voltage power output.
2Power
If battery packs increase output voltage to 56V or above using series connection units, then the ability to power high-power electric tools is improved, but the complexity of voltage detection and disconnection detection circuits increases
Solution Approach 1:
The patent divides the battery pack into multiple series connection units, where each unit contains parallel-connected battery cells. Voltage detection is performed segmentally by monitoring each series connection unit independently through separate detection circuits. This segmentation approach enables high voltage output while managing circuit complexity through modular detection architecture, where each unit's voltage is detected and compared relative to adjacent units.
Solution Approach 2:
The patent introduces a control module as an intermediary that coordinates voltage detection across multiple series connection units. The control module receives voltage signals from detection circuits, compares voltages between adjacent units, and determines disconnection status based on voltage differences. This intermediary control logic simplifies the overall system by centralizing the complex detection and comparison functions rather than requiring direct complex circuitry between all components.
3Power
If battery packs use parallel connection of battery cells within series connection units, then the current capability and power delivery are improved, but the difficulty of detecting cell disconnection increases
Solution Approach 1:
The patent implements feedback-based disconnection detection by continuously monitoring voltage across series connection units and comparing adjacent unit voltages. When a disconnection occurs in parallel-connected cells within a series connection unit, the voltage of that unit changes relative to adjacent units. The control module receives this voltage feedback, compares it with neighboring units, and identifies disconnections based on the voltage difference feedback signal. This feedback mechanism makes disconnection detection feasible despite the parallel connection complexity.
Data Source
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AI summary
A battery pack is provided. The battery pack may include a plurality of series connection units, a voltage detecting module for detecting voltage of the high side of the series connection units in the battery pack, and a battery control module configured to receive the voltage signal from the voltage detecting module and calculate the voltage of the series connection units. Wherein each series connection unit comprises a plurality of battery cells, and the plurality of battery cells in each series connection unit are connected in parallel, wherein the battery control module is capable of determining whether disconnection of the battery cells in the series connection unit has happened according to the voltage of the series connection unit. The battery pack is capable of ensuring user's safety.