Battery Protection Board Circuit for Over-Discharge Isolation

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Solution Overview

Problem

Electronic devices continue to draw power after being turned off, leading to battery over-discharge and potential damage due to impedance in the electric circuit, which causes battery leakage over time.

Innovation Solution

An over-discharge protection circuit is integrated into the battery protection board, utilizing switches and control modules to disconnect the battery from the electric circuit when the voltage drops below a preset threshold, preventing further power discharge.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If the electronic device is turned off, then power consumption is reduced, but battery leakage still occurs due to circuit impedance

Engineering Contradiction:
Improvepower consumptionVSAvoidbattery leakage
Core Design Contradiction:
Use of energy by moving objectVSLoss of energy

Solution Approach 1:

The patent extracts and removes the battery from the circuit by controlling a switch to disconnect the battery when the device is turned off and voltage drops below the threshold. This isolation eliminates the harmful leakage current path while maintaining the device in an off state, directly resolving the contradiction between reduced power consumption and preventing battery leakage.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent applies preliminary anti-action by detecting voltage drop trends before complete battery depletion occurs. The control module monitors voltage in real-time and proactively disconnects the battery when voltage approaches the threshold, preventing the harmful over-discharge condition before it can cause battery damage.

Inventive Principle:
Principle #9Preliminary anti-action

2Reliability

If the switch remains connected to maintain circuit functionality, then device operation is ensured, but battery over-discharge occurs after device shutdown

Engineering Contradiction:
Improvedevice operationVSAvoidbattery over-discharge
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent applies dynamics by making the circuit connection state variable rather than fixed. The switch dynamically changes its state based on real-time voltage monitoring and device operational status. During normal operation, the switch maintains connectivity for reliable device function; after shutdown when voltage drops below threshold, the switch automatically disconnects to prevent over-discharge, thus resolving the contradiction between operational reliability and battery protection.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent implements feedback through continuous voltage monitoring by the control module. The system constantly measures battery voltage and uses this feedback information to control the switch state. When voltage feedback indicates approaching threshold levels after device shutdown, the control module responds by disconnecting the battery, creating a closed-loop control system that simultaneously ensures operational reliability and prevents harmful over-discharge.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP4258511B1Over-discharge protection circuit, battery protection board, and electronic device
Publication Date: 2026.01.28 HONOR DEVICE CO LTD
  • EP4258511B1 patent drawingFigure 1~3
  • EP4258511B1 patent drawingFigure 4~5
  • EP4258511B1 patent drawingFigure 6A~6B

AI summary

Provided are an over-discharge protection circuit, a battery protection board, and an electronic device. The circuit includes: A first end of the over-discharge protection circuit is configured to connect a positive tab of the battery, and a second end of the over-discharge protection circuit is configured to connect a negative tab of the battery. A third end and a fourth end of the over-discharge protection circuit are configured to correspondingly connect the first end and the second end of the battery power acquisition circuit. The first end of the over-discharge protection circuit is connected to the third end of the over-discharge protection circuit. The second end of the over-discharge protection circuit is connected to the fourth end of the over-discharge protection circuit through a first switch. A first control module is connected to a first control end of the first switch, and the first control module is configured to: after the electronic device is turned off, control the first switch to be turned off when a voltage of the battery is lower than a preset first voltage threshold, and control the first switch to be turned on when the voltage of the battery is not lower than the preset first voltage threshold. This application can solve a problem of battery over-discharge after the electronic device is turned off, and reduce a battery loss after the electronic device is turned off