Multi-source Battery Charging Circuit for Voltage Leveling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing charging methods for secondary batteries face challenges in accurately reducing power source voltage during constant voltage charging and leveling cell voltages in parallel connection, due to the use of a single power source and diodes as switches.
Innovation Solution
A charging method and device that utilize different power sources for serial and parallel connections, with a voltage measuring pin to ensure accurate voltage measurement and prevent short circuits, allowing for precise control of charging modes by switching between constant current and constant voltage charging based on measured voltage differences.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single power source is used for both serial and parallel charging, then device complexity is reduced, but voltage measurement accuracy during constant voltage charging deteriorates
Solution Approach 1:
The patent divides the charging function into two separate power sources: a first power source for serial constant current charging and a second power source for parallel constant voltage charging. This segmentation allows each power source to be optimized for its specific charging mode, with the second power source providing accurate voltage control during parallel charging without being constrained by the requirements of serial charging.
2Device complexity
If diodes are used as switches for switching between serial and parallel connections, then device complexity is reduced, but voltage leveling among cells in parallel connection deteriorates
Solution Approach 1:
The patent incorporates voltage measurement pins that continuously monitor the voltage of each cell during charging. This feedback mechanism allows the system to detect voltage differences among cells in parallel connection and adjust the charging current distribution accordingly, ensuring accurate voltage leveling that cannot be achieved with passive diode switches alone.
3Productivity
If voltage measuring pin contacts terminal after conductive pin, then charging speed is maintained, but short circuit risk increases
Solution Approach 1:
The patent designs the voltage measuring pin to contact the cell terminal before the conductive pin during the charging process. This preliminary action ensures that voltage measurement is established before full charging current is applied, allowing the system to detect and respond to abnormal voltage conditions before they can cause short circuits or damage, while maintaining charging efficiency.
Data Source
AI summary
A charging method of a secondary battery having plural cells includes: connecting the plural cells in series and conducting constant current charging by a first power source; measuring voltages of the plural cells; and connecting the plural cells in parallel and conducting constant voltage charging by a second power source, a voltage of which is lower than a voltage of the first power source, in the case where a measured voltage difference among the plural cells is smaller than a specified value.