Secondary Battery Charging Method for Voltage Imbalance Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional secondary battery charging methods fail to address voltage imbalances among cells effectively, leading to uneven degradation, reduced battery life, and safety hazards, especially when voltage differences are between 100 mV and 300 mV, resulting in economic losses and potential safety risks.
Innovation Solution
A method and device that dynamically switch between constant current-constant voltage (CC-CV) charging and pulse charging based on voltage imbalances among cells, with CC-CV charging used for imbalances less than 100 mV, pulse charging for imbalances between 100 mV and 300 mV, and blocking electrical path for imbalances above 300 mV, utilizing a voltage measuring portion, comparator, imbalance detector, charge controller, and charge setting portion to manage charging.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If CC-CV charging method is used with high charging current to reduce charging time, then charging speed is improved, but battery performance degradation occurs
Solution Approach 1:
The patent applies periodic action by implementing pulse charging that alternates between charging and pausing phases. The charging current is applied in pulses with specific duty cycles (e.g., 10-90%, 20-80%, 30-70%) rather than continuously, allowing the battery to rest periodically and recover, thus reducing degradation while maintaining acceptable charging speed.
Solution Approach 2:
The patent employs dynamics by dynamically adjusting the charging current based on real-time battery state monitoring. The system transitions between different charging phases (constant current, constant voltage, pulse charging) and adjusts pulse parameters (amplitude, duty cycle, width) according to battery voltage, current, and temperature conditions, optimizing both charging speed and battery health.
2Device complexity
If cells are charged simultaneously with uniform timing control, then charging process is simplified, but voltage imbalance and uneven degradation occur among cells
Solution Approach 1:
The patent applies local quality by implementing individualized charging control for each cell based on its specific state. The system monitors voltage, current, and temperature of each cell separately and adjusts charging parameters (current allocation, pulse timing, duty cycle) on a per-cell basis, allowing each cell to be charged according to its own characteristics rather than uniform treatment.
Solution Approach 2:
The patent employs parameter changes by dynamically modifying charging parameters (current magnitude, pulse width, duty cycle, voltage thresholds) based on real-time battery state. The system adjusts these parameters differently for each cell to compensate for degradation differences, maintaining voltage balance while managing the complexity through intelligent control algorithms.
3Object-affected harmful factors
If voltage difference threshold is set at 300 mV or more for interrupting charging, then safety is improved, but economic loss occurs due to premature discarding of usable cells
Solution Approach 1:
The patent applies dynamics by implementing dynamic voltage balance control that actively manages cell voltage differences through differentiated charging strategies. The system continuously monitors voltage imbalances and adjusts charging parameters in real-time to prevent voltage differences from reaching dangerous thresholds, extending battery life while maintaining safety.
Solution Approach 2:
The patent employs preliminary action by implementing preventive voltage balance management before critical voltage differences develop. The system detects and addresses minor voltage imbalances early through adjusted charging parameters, preventing them from escalating to the 300 mV threshold that would trigger safety shutdowns or premature battery replacement.
Data Source
AI summary
A method of charging a secondary battery and a charging device that can improve stability and extend the life span of the battery. When the secondary battery includes a plurality of cells, the charging method is changed when a voltage imbalance from 100 mV to 300 mV occurs among the cells. In that range, the charging method changes from a constant current-constant voltage charging method to a pulse-charging method. When the voltage imbalance is 300 mV or more, the electricity path is blocked, shutting down the battery. When the voltage imbalance is 100 mV or less, the constant current-constant voltage charging method is maintained. The method and device also stop charging when the battery reaches full charge.