Charge Control Device for Energy Harvesting Battery Charging
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Solution Overview
Problem
Energy harvesting systems face significant power loss due to charging inefficiencies, particularly at the end stage of battery charging, where the charging current decreases, leading to heat loss and reduced power generation efficiency.
Innovation Solution
A charge control device that monitors the actual charging current and switches the charging destination to a different battery unit when a reduction in charging current is detected, maintaining constant current charging and preventing power loss by ensuring that no battery unit reaches full charge.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If constant current charging is performed until the battery reaches full charge, then the battery charge amount is maximized, but charging loss increases due to current reduction at the end stage
Solution Approach 1:
The patent divides the charging system into multiple battery units (first battery unit and second battery unit) that can be charged alternately. When one battery unit reaches full charge, the charging switches to the other unit, ensuring continuous constant current charging without the current reduction losses that occur in single-battery constant voltage charging.
Solution Approach 2:
The patent implements periodic switching between multiple battery units for charging. The charging control unit alternates between the first and second battery units in a cyclic manner, maintaining constant current charging continuously by switching targets when one unit reaches full charge, thereby eliminating the energy loss associated with end-stage constant voltage charging.
2Productivity
If energy harvesting is used as external power source, then power generation efficiency is improved, but charging loss must be reduced further to maximize efficiency
Solution Approach 1:
The patent ensures continuous constant current charging by switching between multiple battery units. This eliminates the interruption and current reduction that occurs in traditional single-battery charging, maintaining maximum useful action (charging) throughout the entire charging period and maximizing the utilization of harvested energy.
Data Source
AI summary
A charge control device uses external electricity to charge a plurality of battery devices. A constant current source uses the external electricity to generate and adjust an output current amount to a constant target value. A selector selects one battery device from the plurality of battery devices and supplies output current from the constant current source to the one battery device. A measurer measures an amount of actual current flowing from the constant current source to the one battery device. An instructor monitors a measured value provided by the measurer and instructs the selector, when the measured value meets a condition for a reduction of charging current amount to be regarded as having occurred, to change a destination to which the output current of the constant current source is supplied from the one battery device to a different battery device.