Method and system for a battery monitoring circuit
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Solution Overview
Problem
Existing battery monitoring circuits are complex and costly due to the need for high-rated voltage sensors and processing units to determine battery impedance, which increases the overall complexity and expense of the system.
Innovation Solution
A battery monitoring circuit with multiple current loops and a method of operation that reduces the voltage experienced by the voltage sensor, allowing for the use of low-rated sensors and simplifying the circuit design, including the use of switches and capacitors to manage current flow and impedance measurement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional battery monitoring circuits use high-rated voltage sensors and processing units to determine battery impedance, then measurement precision is improved, but device complexity and manufacturing cost increase
Solution Approach 1:
The patent divides the battery monitoring function into multiple current loops (first current loop, second current loop, third current loop) that can be selectively activated. Each loop serves a specific measurement purpose, allowing the system to break down the complex impedance measurement task into simpler, manageable segments that reduce overall circuit complexity while maintaining measurement precision.
Solution Approach 2:
The patent employs periodic switching between different current loops to perform impedance measurements at different times. The controller selectively closes switches to activate specific current loops in a periodic manner, allowing the same physical circuit to perform multiple measurement functions sequentially. This time-division approach reduces the need for complex simultaneous measurement circuits.
2Reliability
If conventional battery monitoring circuits use high-rated voltage sensors to handle full battery voltage, then reliability is improved, but manufacturing cost increases
Solution Approach 1:
The patent introduces current loops with known impedances as intermediary elements between the battery and the voltage sensor. These current loops act as mediators that transform the high-voltage measurement problem into a low-voltage measurement problem. The voltage sensor only needs to measure the small voltage drop across the current loop impedance rather than the full battery voltage, allowing the use of low-rated, cost-effective sensors while maintaining measurement reliability.
3Ease of manufacture
If multiple current loops are used to reduce voltage at the sensor, then manufacturing cost decreases, but device complexity increases
Solution Approach 1:
The patent designs the current loops and switches to serve multiple functions simultaneously. The same current loop structure is used for both voltage reduction (to protect the sensor) and impedance measurement (to determine battery health). The switches serve both to activate/deactivate loops and to configure the measurement circuitry. This multi-functionality approach reduces the need for separate dedicated components, thereby controlling overall device complexity despite the presence of multiple loops.
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
The solution results in a less complex and less costly battery monitoring circuit that effectively determines battery health by using a simple combination of current loops and reduced voltage sensing, reducing manufacturing burdens and costs compared to conventional systems.
Implementation Method 1
One method of determining the health of a battery is by measuring and evaluating its impedance. Impedance measurement is done by injecting a sinusoidal current into the battery terminals and measuring the injected sinusoidal current and the voltage across the battery.
Data Source
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AI summary
A method (140) and system for determining the health of a set of batteries (102) through the use of a battery monitoring circuit (100). The battery monitoring circuit (100) including a first current loop (124) and a second current loop (126). The first current loop (124) being enabled by a first switch (104), a first resistor (112) and a second switch (106). The second current loop (126) being enabled by the first switch (104), a third switch (108), a voltage sensor (150), and the second switch (106).