Battery Pack Fuse Blowing Mechanism for Self-Discharge Protection
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Solution Overview
Problem
Battery packs face the risk of explosion or ignition due to self-discharging, where the voltage drops to critically low levels, causing a short circuit between electrodes, especially when left unused for extended periods.
Innovation Solution
A battery pack design that includes a control unit to monitor voltage levels and trigger a fuse blowing mechanism when the voltage falls below a certain threshold for an extended duration, disconnecting the battery stacks from the output terminal to prevent charging and thus avoid overheating and potential explosions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the discharging switch is turned off to stop discharging when voltage drops to 2.0-3.0V, then the battery cell is protected from over-discharge, but the battery cell may still drop to 0-1.0V due to self-discharging over time, causing copper melting and short circuit
Solution Approach 1:
The patent introduces a fuse as an intermediary protective element in the circuit. When voltage drops to critical levels (0-1.0V), the fuse blows to physically disconnect the circuit, preventing copper melting and electrode short circuit. This intermediary mechanism addresses the limitation of electronic switches that cannot prevent self-discharge damage over time.
Solution Approach 2:
The patent implements preliminary protective action by designing the fuse to blow at critical voltage thresholds before catastrophic failure occurs. The control unit monitors voltage continuously and triggers fuse blowing when voltage reaches dangerous levels, preventing the progression from over-discharge to copper melting and short circuit.
2Duration of action of stationary object
If the battery pack is left alone for a long time, then the battery cell voltage naturally stabilizes, but self-discharging continues to decrease voltage to critically low levels, causing safety hazards
Solution Approach 1:
The patent implements continuous voltage monitoring with feedback control. The control unit constantly measures battery voltage and compares it against predefined thresholds. When voltage drops to critical levels during storage, the system automatically triggers fuse blowing to disconnect the circuit, preventing safety hazards from prolonged self-discharge.
Solution Approach 2:
The fuse serves as a passive intermediary that automatically responds to critical voltage conditions during storage. It provides long-term protection without requiring active intervention, safely disconnecting the circuit if self-discharge progresses to dangerous levels during extended storage periods.
3Ease of operation
If a standard switch is used to disconnect battery stacks, then the battery can be controlled, but it cannot automatically protect against over-discharge damage caused by self-discharging
Solution Approach 1:
The patent implements self-service protection through the fuse mechanism. When voltage drops to critical levels, the system automatically triggers fuse blowing without requiring manual intervention. This self-acting mechanism provides reliable automatic protection against over-discharge damage, complementing the manual control capability of standard switches.
Solution Approach 2:
The fuse acts as an automatic intermediary protective device that activates when voltage reaches critical thresholds. It provides fail-safe protection that operates independently of manual control, ensuring reliability even when the battery is left unattended for extended periods.
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
Effectively prevents accidents by ensuring the battery pack is safely disconnected from charging when it reaches a critically low voltage state, thereby preventing short circuits and potential explosions.
Implementation Method 1
a heating element connected to the fuse in parallel, configured to generate heat to melt the fuse when a voltage between the positive terminal and the negative terminal is lower than a threshold voltage
Data Source
Figure 1
Figure 2A
Figure 2B
AI summary
A battery pack includes a first battery stack (11) having a plurality of battery cells connected in series, a second battery stack (12) having a plurality of battery cells connected in series and connected in parallel to the first battery stack, a controller (13) for sensing voltages of the plurality of battery cells of the first battery stack and the plurality of battery cells of the second battery stack and for outputting a fuse blowing signal when at least one of the sensed voltages is lower than a first reference voltage, and a fuse blowing unit (14) for electrically decoupling the first and second battery stacks from an output terminal of the battery pack in response to the fuse blowing signal from the controller. A fuse blowing signal is also sent to the fuse blowing unit when the at least one of the sensed voltages is higher than a second reference voltage.