Auxiliary Battery Status Determination Using Internal Resistance
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Solution Overview
Problem
Existing technologies face difficulties in accurately determining the status of auxiliary batteries in vehicles equipped with start-stop functions, particularly when high inrush currents do not flow, as they struggle to monitor the battery status effectively.
Innovation Solution
A status determination device that includes a sensor to detect the terminal voltage and current of an auxiliary battery, along with an internal resistance calculator, which calculates the internal resistance based on detected values during stable periods before and after the auxiliary equipment is started, allowing for accurate status determination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a small full-scale current sensor is used to estimate battery status, then the device complexity is reduced, but the measurement precision deteriorates when high inrush currents are not present
Solution Approach 1:
The patent applies preliminary action by measuring the terminal voltage and current in advance during a stable period before auxiliary equipment starts, and before high inrush current flows. This pre-measurement allows calculation of internal resistance when conditions are favorable, which then enables accurate battery status determination even when high inrush currents are not present. The timing of measurements is carefully controlled to capture data before disruptive current events occur.
2Reliability
If battery status is monitored during high inrush current periods, then the reliability of status determination is improved, but the measurement precision deteriorates due to current fluctuations
Solution Approach 1:
The system performs measurements in advance during stable periods before auxiliary equipment starts, avoiding the problematic high inrush current periods. By calculating internal resistance beforehand when current fluctuations are minimal, the system ensures both reliability and precision without requiring measurements during disruptive current events.
Solution Approach 2:
The patent dynamically adjusts the timing of measurements based on the operational state of auxiliary equipment. It identifies stable periods when voltage and current fall within predetermined fluctuation ranges, and performs measurements only during these favorable conditions. This dynamic timing adjustment ensures measurements are taken when precision is maximized, avoiding periods when reliability would be compromised by current fluctuations.
3Measurement precision
If internal resistance is calculated using voltage and current during stable periods, then the measurement precision is improved, but the reliability deteriorates when auxiliary equipment starts causing current fluctuations
Solution Approach 1:
The system continuously monitors terminal voltage and current, and uses this feedback to determine when stable periods occur. When voltage and current fall within predetermined fluctuation ranges, the system triggers internal resistance calculation. This feedback mechanism ensures measurements are taken at the optimal moments, maintaining precision while ensuring reliability through continuous monitoring of system state.
Solution Approach 2:
By calculating internal resistance in advance during stable periods before auxiliary equipment starts, the system establishes a baseline measurement under favorable conditions. This preliminary calculation remains valid for status determination even when subsequent current fluctuations occur, as the internal resistance characteristic is relatively stable over short periods.
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 precise and appropriate determination of auxiliary battery status, even when high inrush currents are not present, by calculating internal resistance within predetermined fluctuation ranges, ensuring reliable battery monitoring.
Implementation Method 1
a sensor that detects a magnitude of a terminal voltage of an auxiliary battery and a magnitude of a current
Implementation Method 2
an internal resistance calculator that calculates an internal resistance of the auxiliary battery based on the magnitude of the terminal voltage and the magnitude of the current detected by the sensor
Data Source
AI summary
A sensor of a status determination device detects a magnitude of a terminal voltage of an auxiliary battery provided separately from a driving battery and a magnitude of a current flowing through the auxiliary battery. The driving battery is an electrical power source for a driving motor of a vehicle, and the auxiliary battery is an electrical power source for auxiliary equipment and has an output voltage lower than that of the driving battery. An internal resistance calculator calculates an internal resistance of the auxiliary battery based on the magnitude of the terminal voltage and the magnitude of the current detected by the sensor in a stable period that is before the auxiliary equipment is started and in which the magnitude of the terminal voltage and the magnitude of the current fall within predetermined fluctuation ranges, and those detected in a period after starting of the auxiliary equipment is detected.