Secondary Battery Capacity Measurement Using Current-Dependent Voltage Correction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing secondary-battery maximum-capacity measuring apparatuses struggle to accurately measure the maximum capacity of secondary batteries in use, particularly when the output current is not zero, due to load dependency issues and internal resistance variations.
Innovation Solution
A secondary-battery maximum-capacity measuring apparatus that includes a current dependency processing unit to convert inter-terminal and open cell voltages into values independent of load current, using relative voltage changes and gradient characteristics, and an error calculation unit to compute errors, allowing for accurate maximum capacity measurement even when the battery is in use.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If maximum capacity measurement is performed during battery use with non-zero output current, then measurement can be conducted in practical operating conditions, but measurement precision deteriorates due to load dependency and internal resistance variations
Solution Approach 1:
The patent introduces an intermediary processing mechanism that measures the relationship between output current and voltage (load dependency characteristics) during battery use, then uses this intermediate data to correct the maximum capacity measurement. By measuring the load dependency as an intermediary factor and applying correction based on this intermediate measurement, the system achieves accurate maximum capacity measurement under practical operating conditions with non-zero current.
2Productivity
If conventional measurement methods are used with load dependency, then measurement can be performed under practical operating conditions, but measurement precision deteriorates due to internal resistance variations
Solution Approach 1:
The patent implements a feedback mechanism where the load dependency characteristics (relationship between output current and voltage) are continuously measured during battery operation. This measured load dependency information is then fed back to correct the maximum capacity calculation, compensating for internal resistance variations. The feedback loop enables the system to adapt to changing operating conditions and maintain measurement accuracy during practical use.
Data Source
AI summary
A secondary-battery maximum-capacity measuring apparatus, includes: a current dependency processing unit configured to convert an inter-terminal voltage and an open cell voltage of a secondary battery into values without depending on a load current based on an amount of change in relative value of a voltage during a time period when a constant current is drawn from the secondary battery; and an error calculation unit configured to compute errors of the inter-terminal voltage and the open cell voltage of the secondary battery, the inter-terminal voltage and the open cell voltage being converted by the current dependency processing unit.