USB-C Vehicle Battery Charging for Overdischarge Voltage Matching
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Solution Overview
Problem
Conventional portable battery charging apparatuses for vehicles lack versatility as they cannot charge vehicles without a cigar jack and require larger structures to manage voltage differences during overdischarge, especially when the terminal voltage drops below 8.5V.
Innovation Solution
A vehicle battery charging apparatus that connects to a portable charger via a USB Type-C cable, utilizing a power supply and reception circuit, a charging determination circuit, and a supply requesting and reception setting circuit to adaptively charge the vehicle battery according to its voltage state, using the USB Power Delivery standard to reduce the size of the charging circuit by matching the charging voltage to the battery's terminal voltage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a portable battery charging apparatus is designed to connect to a cigar jack for charging vehicle batteries, then it can provide emergency charging capability, but it lacks versatility for vehicles without a cigar jack and requires additional voltage absorption circuits when terminal voltage drops below 8.5V
Solution Approach 1:
The charging apparatus uses a USB Type-C interface that can universally connect to various vehicles including those without cigar jacks. The interface supports both power reception (charging the vehicle battery) and power supply (providing emergency power) functions, making the device adaptable to different vehicle types and charging scenarios without requiring additional voltage absorption circuits
Solution Approach 2:
The apparatus dynamically adjusts the charging voltage based on the vehicle battery's terminal voltage state. When the terminal voltage is low (below 8.5V), the system automatically reduces the charging voltage to match the battery's current state, eliminating the need for voltage absorption circuits and reducing overall device complexity while maintaining compatibility
2Device complexity
If the output voltage is set to a fixed value (e.g., 16.8V) for charging, then the charging process is simplified, but additional circuits are required to handle large potential differences when the vehicle battery is overdischarged (terminal voltage 8.5V or lower)
Solution Approach 1:
The charging voltage is not fixed but dynamically adjusted based on the vehicle battery's terminal voltage. The system monitors the terminal voltage and automatically adjusts the output voltage to be higher than the terminal voltage by a predetermined margin (e.g., 2V or 3V) to ensure reliable charging while avoiding the need for complex voltage absorption circuits that would be required with a fixed high voltage output
Solution Approach 2:
The charging determination circuit continuously monitors the vehicle battery's terminal voltage and provides feedback to the supply requesting and reception setting circuit. Based on this feedback, the system adjusts the charging parameters in real-time, ensuring that the charging voltage is always appropriate for the battery's current state, thereby maintaining charging reliability without requiring additional protection circuits
3Reliability
If a dedicated charging terminal is used for vehicle battery charging, then the charging process is reliable and controlled, but the device cannot be used in vehicles without such dedicated terminals
Solution Approach 1:
The USB Type-C interface serves multiple functions: it can connect to vehicles with or without dedicated charging terminals, support both power reception and power supply operations, and provide data communication. This universal interface maintains reliable charging control through the USB PD protocol while enabling compatibility with a wide range of vehicles including those without traditional cigar jacks or dedicated charging ports
Data Source
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AI summary
A vehicle battery charging apparatus includes an USB power source that selectively performs a power input operation as a power reception side or a power output operation as a power supply side, via an USB Type-C terminal, a charging determination circuit that determines whether charging of the vehicle battery is required, and a PD controller that requests a mobile battery to operate as the power supply side and sets the USB power source to operate as the power reception side when the charging determination circuit determines that the charging is required.