Dynamic Charging Current Control for Battery Cell Voltage Balancing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing battery charging methods often result in incomplete charging due to the need to stop the charging process when one energy cell reaches its maximum voltage, potentially leading to overcharging of other cells and safety risks like explosions or fires, especially in lithium-ion batteries.
Innovation Solution
A system that includes a scanning device for cell voltages and a processing device to determine a setpoint charging current based on voltage differences between cells, allowing for balanced charging and avoiding overcharging by adjusting the charging current dynamically, while also considering temperature to ensure safe and complete charging.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the charging current is switched off when one energy cell reaches maximum voltage, then overcharging is prevented, but the battery cannot be fully charged as other cells remain below maximum voltage
Solution Approach 1:
The charging current is dynamically adjusted based on real-time cell voltage differences. Instead of using a fixed cutoff threshold, the system continuously monitors voltage deviations and modulates the charging current accordingly, allowing the charging process to adapt to the varying states of individual cells and achieve more complete charging while preventing overcharging
Solution Approach 2:
The system changes the charging parameter (current magnitude) based on the state of charge differences between cells. By adjusting the charging current as a function of voltage differences, the system optimizes the charging process to balance all cells simultaneously, transforming the static cutoff approach into a dynamic parameter adjustment strategy
2Device complexity
If a fixed charging current is used, then the charging process is simple, but cell voltage differences increase leading to incomplete charging
Solution Approach 1:
The system implements feedback control by continuously measuring cell voltages and using the voltage differences to adjust the charging current. The charging device receives feedback about the state of charge of each cell and automatically modifies the charging parameters to minimize voltage imbalances, achieving optimal charging without complex manual intervention
Data Source
AI summary
An electrically chargeable energy store includes a plurality of energy cells connected in series, a scanning device for the cell voltages of the energy cells, and a processing device for determining a setpoint charging current through the energy cells based on the scanned cell voltages. The processing device is equipped to determine the setpoint charging current as a function of differences between the scanned cell voltages. A method for charging an electrically chargeable energy store includes steps of scanning of the cell voltages of the energy cells, determining a setpoint charging current through the energy cells based on the differences of the scanned cell voltages, and limiting of a charging current flowing through the energy cells to the determined setpoint charging current.