Battery State-of-Function Prediction via Synchronous Internal Resistance Measurement
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Solution Overview
Problem
Existing battery state-of-function prediction methods are imprecise and complex, particularly in estimating the battery state-of-health, which affects the reliability of start-stop functions in vehicles and fuel saving potential.
Innovation Solution
An apparatus and method that synchronously measures battery voltage and current during high current dynamic discharging events to precisely determine internal resistance, using a sensor unit and evaluation unit, allowing for improved prediction of battery state-of-function by estimating internal resistance during subsequent events, thereby simplifying the prediction process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional battery monitoring systems are used to predict state-of-function, then information about battery state-of-charge and state-of-health is provided, but the measurement or estimation of battery state-of-health is complicated and imprecise
Solution Approach 1:
The patent extracts the critical parameter for state-of-function prediction (internal resistance) from the complex state-of-health estimation process. By focusing measurement efforts solely on internal resistance through synchronous voltage and current measurements during high current discharge events, the system achieves precise state-of-function prediction without the complexity of comprehensive state-of-health monitoring
Solution Approach 2:
The patent changes the measurement parameters from traditional state-of-health indicators (cycle count, capacity) to dynamic operational parameters (synchronous voltage and current during high current discharge). This parameter transformation enables direct calculation of internal resistance, providing a simple yet precise metric for predicting battery state-of-function and crank-ability
2Ease of operation
If end of discharge measurements are used to determine battery state, then battery quality level information is obtained, but measurements are barely possible during vehicle operation
Solution Approach 1:
The patent performs preliminary measurements during high current discharge events (such as engine cranking) to capture internal resistance data before the battery reaches end-of-discharge conditions. By measuring during these transient high-stress events, the system obtains critical state-of-function information while the battery is still operational and providing power
Solution Approach 2:
The system performs periodic synchronous measurements of voltage and current during high current discharge events that occur naturally during vehicle operation (start-stop cycles, accessory loading). This periodic sampling during operational stress events provides continuous state-of-function assessment without requiring dedicated end-of-discharge testing
3Measurement precision
If estimation models based on charging and discharging cycles are used, then battery state-of-health is determined, but the prediction accuracy is imprecise
Solution Approach 1:
The patent replaces complex mechanical/cycle-based estimation models with direct electrical measurements. Instead of using algorithms that count charge/discharge cycles and estimate degradation, the system directly measures internal resistance through synchronous voltage and current measurements during high current discharge, providing immediate and accurate state-of-function prediction
Solution Approach 2:
The battery essentially tests itself during normal high current discharge operations (engine cranking, starter motor operation). The natural operational stresses cause the battery to exhibit its true internal resistance characteristics, which the monitoring system captures through synchronous measurements, eliminating the need for external testing equipment or complex predictive algorithms
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
This approach enhances the accuracy and simplifies the prediction of battery state-of-function, specifically crank-ability, by using a limited set of parameters like internal resistance, temperature, and state-of-charge, reducing complexity and improving reliability in vehicle power systems.
Implementation Method 1
The evaluation unit is configured to determine at least the internal resistance of a battery based on a synchronous measurement of a battery voltage and a battery current by the sensor unit during at least one previous high current dynamic discharging event
Data Source
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AI summary
Apparatus for predicting a battery state-of-function, in particular the crank-ability of an engine starter battery, comprising a sensor unit configured for synchronously measuring a battery voltage and a battery current, and an evaluation unit for evaluating quantities measured by the sensor unit, wherein the evaluation unit is configured to determine at least the internal resistance of a battery based on a synchronous measurement of a battery voltage and a battery current by the sensor unit during at least one previous high current dynamic discharging event.