Lead Battery State Determination Using Temperature-Corrected Voltage
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional methods for determining the state of a lead battery in vehicles lack accuracy in assessing the State of Health (SOH) due to insufficient knowledge about the battery's characteristics, which are influenced by factors like temperature and SOC, leading to potential erroneous determinations.
Innovation Solution
A battery state determining apparatus that measures open-circuit voltage, engine starting voltage, and vehicle temperature, using correction algorithms to calculate a determination voltage, and a characteristic map to accurately assess the battery state by defining relationships between SOH, open-circuit voltage, and minimum voltage, thereby reducing the influence of temperature variations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional voltage measurement methods are used for battery state determination, then the measurement process is simple, but the determination accuracy is poor due to insufficient consideration of temperature and SOC influences
Solution Approach 1:
The patent applies parameter changes by introducing temperature and SOC as correction parameters to the voltage measurement system. The correction section modifies the raw voltage measurement based on these parameters to compensate for their influencing effects, thereby improving determination accuracy without requiring fundamentally new measurement principles
Solution Approach 2:
The correction section acts as an intermediary between the voltage measurement and the final battery state determination. It processes the raw voltage data by applying temperature and SOC corrections, serving as a mediator that transforms inaccurate direct measurements into accurate battery state indicators
2Measurement precision
If direct temperature measurement of vehicle parts is implemented, then temperature compensation accuracy improves, but noise interference and measurement complexity increase
Solution Approach 1:
Instead of directly measuring the battery temperature which may be noisy, the patent uses the vehicle temperature as a copied proxy parameter. This indirect measurement approach captures the essential temperature influence on battery performance while avoiding the noise and complexity associated with direct battery temperature sensing
Solution Approach 2:
The vehicle temperature measurement serves as an intermediary that indirectly provides temperature compensation information for the battery. Rather than directly measuring the battery's temperature which may be difficult and noisy, the system uses the easily measurable vehicle temperature as a mediator to achieve temperature compensation
Data Source
AI summary
A battery state determining apparatus is provided which can accurately determine a state of a lead battery in an automotive vehicle. The apparatus calculates a corrected engine starting voltage Vst1 from an open-circuit voltage (OCV) measuring section that measures the open circuit voltage Vst of the lead battery at an engine starting time in accordance with a temperature of the vehicle. The apparatus further calculates a battery determination voltage Vst_th representing a voltage of the lead battery at an engine starting time when a growth rate of internal resistance of the lead battery reaches a predetermined value from the open-circuit voltage OCV. The apparatus then determines the battery state of the lead battery by determining whether the corrected engine starting voltage Vst1 is larger than the battery determination voltage Vst_th and whether the corrected engine starting voltage Vst1 belongs to a predetermined region on a characteristic map.