Lead-Acid Battery Life Prediction with Overcharge and Resistance Monitoring
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Solution Overview
Problem
Existing diagnostic methods for lead-acid batteries in backup energy storage applications cannot accurately predict their lifespan and require extensive laboratory testing, making them impractical for in-situ monitoring.
Innovation Solution
A method involving continuous measurement of overcharge current and periodic measurement of internal resistance under direct current, followed by normalization and comparison to calibration data, allows for the estimation of battery aging and remaining life.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If complete discharge testing is performed to accurately determine battery capacity and health, then measurement precision is improved, but loss of time increases due to long measurement and recharging periods
Solution Approach 1:
The patent uses short-duration current pulses instead of complete discharge cycles to obtain diagnostic information. Brief current pulses are applied to measure voltage responses, providing sufficient data on battery internal resistance and capacity without requiring lengthy discharge-recharge cycles. This disposable-like approach uses minimal energy and time while still achieving diagnostic goals.
Solution Approach 2:
The patent applies partial action by using brief current pulses rather than complete discharge cycles. The pulses are sufficient to elicit measurable voltage responses that reveal battery health information, but they do not deplete the battery. This partial action achieves the diagnostic objective without the time penalty of full discharge testing.
2Productivity
If internal resistance estimation is performed using impedance measurements or continuous discharge pulses, then productivity is improved by enabling rapid testing, but measurement precision deteriorates compared to complete discharge methods
Solution Approach 1:
The patent employs feedback by continuously monitoring voltage responses during brief current pulse applications. The system measures the voltage drop and recovery characteristics in real-time, using this feedback to calculate internal resistance and estimate capacity. This feedback mechanism allows rapid assessment while maintaining reasonable accuracy by adapting measurements to the battery's actual response.
Solution Approach 2:
The patent changes measurement parameters by using brief current pulses with controlled amplitudes and durations rather than sustained discharge currents. By varying pulse characteristics and analyzing voltage responses, the method extracts multiple diagnostic parameters (internal resistance, capacity indicators) from short measurements, achieving both speed and acceptable precision.
3Reliability
If floating charge voltage is maintained at high levels to compensate for self-discharge, then reliability is improved by ensuring battery readiness, but object-generated harmful factors increase due to oxygen release and electrode corrosion
Solution Approach 1:
The patent uses feedback by continuously monitoring battery voltage and adjusting the floating charge voltage accordingly. Instead of maintaining a constantly high charging voltage, the system responds to actual battery needs, applying voltage only when required to compensate for self-discharge. This feedback-controlled approach maintains reliability while minimizing excessive charging that causes oxygen evolution and corrosion.
Solution Approach 2:
The patent applies dynamics by making the floating charge voltage adjustable and responsive rather than fixed and constant. The charging voltage dynamically adapts to battery state, increasing when self-discharge requires compensation and decreasing when the battery is fully charged. This dynamic approach reduces the time spent at high charging voltages, thereby reducing harmful side reactions while maintaining backup readiness.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables reliable, in-situ diagnosis of battery health and prediction of remaining lifespan, reducing the need for laboratory testing and ensuring timely replacement of batteries.
Implementation Method 1
periodic measurement, under direct current, of the internal resistance (R 120s ) of the battery
Implementation Method 2
Lead-acid batteries are a set of lead-sulfuric acid accumulators connected in series
Implementation Method 3
floating charge is a continuously applied voltage controlled overcharge aimed at compensating self-discharge processes
Implementation Method 4
Electrolysis of water: H 2 O → 2H 2 ↑ + O 2 ↑
Data Source
Figure 1A~2A
Figure 2B~3B
Figure 4A~4C
AI summary
The invention essentially consists of a new method for diagnosing lead-acid batteries and, advantageously, for estimating their remaining lifespan, particularly for backup power storage applications. The method is based on a combination of continuous monitoring measurements with integration of the overcharge current (calculating the Ah of overcharge applied to the battery upon installation) and periodic DC measurements of the battery's internal resistance using short discharge periods with a constant current or constant power.