Lead-Acid Maintenance Charging With Temperature-Based CV Cutoff
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional maintenance charging methods for lead acid batteries are prone to overcharge or insufficient charge due to temperature-dependent internal resistance changes, affecting charge acceptability and leading to battery deterioration.
Innovation Solution
A method that performs constant voltage charging after constant current charging, with the decision to continue or terminate constant voltage charging based on the battery's temperature and calculated charging rate, using temperature-corrected current values to manage charge acceptability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional maintenance charging is performed without temperature consideration, then the charging process is simple, but overcharge or insufficient charge occurs depending on temperature conditions
Solution Approach 1:
The patent changes the control parameter from fixed time-based charging to temperature-adjusted charging. The controller determines temperature of the battery and adjusts the constant voltage charging termination condition based on temperature, thereby preventing overcharge or insufficient charge across different temperature conditions without requiring complex additional hardware
Solution Approach 2:
The patent implements feedback control by continuously monitoring battery temperature and adjusting the charging termination condition accordingly. The controller uses temperature feedback to dynamically set the appropriate charging threshold, ensuring accurate charging completion determination across varying temperature conditions
2Reliability
If constant voltage charging is performed for a predetermined time, then the charging process is simple, but charge acceptability changes with temperature leading to deterioration
Solution Approach 1:
The patent changes the operational parameter from fixed time-based charging to temperature-based charging control. By determining battery temperature and setting appropriate charging termination conditions for different temperature ranges, the system prevents deterioration caused by temperature-mismatched charging while maintaining straightforward controller implementation
3Measurement precision
If internal resistance changes are not compensated for, then the charging control is simple, but charge acceptability varies with temperature causing overcharge or insufficient charge
Solution Approach 1:
The patent addresses measurement accuracy by changing from ignoring temperature effects to actively measuring and compensating for temperature-induced internal resistance changes. The controller determines battery temperature and uses this information to adjust charging parameters, thereby achieving accurate charge state detection across temperature variations without requiring complex additional measurement equipment
Data Source
AI summary
A method for controlling maintenance charging and a power storage system capable of suppressing occurrence of overcharge and insufficient charge in recovery charging are described. Constant voltage charging is performed after constant current charging as the maintenance charging. During the constant voltage charging, whether to continue or terminate the constant voltage charging is determined based on the temperature of the battery and a threshold value. The temperature of the battery is determined using a charging rate calculated from a total charge amount and a total discharge amount of the battery that are calculated from a current value of the battery.