Battery Draw Monitor Using a Shunt for Accurate Parasitic Current Testing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for measuring parasitic draw in automotive systems are either inaccurate due to electromagnetic interference or require switching between high and low current circuits, leading to false positives and excessive downtime, especially when dealing with high current draws in modern vehicles.
Innovation Solution
A battery draw monitor that combines a multi-meter with a high-current electrical shunt, allowing direct measurement of up to 100 amps without needing to switch circuits, ensuring accurate readings and minimizing false positives by using a specific resistance shunt and external power supply, and a non-conductive case for safety.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If an amp clamp is used to measure parasitic draw, then the measurement can be performed without disconnecting the battery cable, but the measurement accuracy deteriorates due to electromagnetic interference and false positives
Solution Approach 1:
The patent introduces a current loop adapter as an intermediary device that connects between the battery cable and the vehicle's electrical system. This adapter provides a dedicated low-impedance path for current measurement that is isolated from electromagnetic interference, thereby maintaining measurement accuracy while avoiding the need to disconnect the battery cable. The adapter acts as a mediator that bridges the gap between the existing battery cable connection and the measurement requirements.
2Measurement precision
If a multi-meter or oscilloscope is used to directly measure current, then measurement accuracy is improved, but the device complexity increases and the measurement process becomes more complex
Solution Approach 1:
The patent extracts the measurement function from complex equipment like multi-meters and oscilloscopes by incorporating a dedicated current sensing circuit directly into the battery cable adapter. This extracted measurement capability uses a simple ammeter and comparator circuit that is specifically designed for this application, eliminating the need for sophisticated external measurement equipment while maintaining accuracy for detecting parasitic draw conditions.
Solution Approach 2:
The system performs self-diagnosis by continuously monitoring current flow through the battery cable and automatically detecting parasitic draw conditions without requiring external measurement equipment. The integrated ammeter and comparator circuit within the adapter enables the system to self-identify abnormal current conditions, eliminating the need for separate measurement devices and simplifying the overall diagnostic process.
3Measurement precision
If a high-current switch is used to redirect current, then the measurement can be performed after the vehicle sleeps, but time is lost due to waiting for the vehicle to sleep and potential fuse blowouts
Solution Approach 1:
The patent enables continuous current monitoring by integrating the measurement circuit directly into the battery cable connection that remains permanently connected. The ammeter and comparator circuit continuously measure current flow without interruption, allowing immediate detection of parasitic draw conditions at any time without requiring the vehicle to be in a sleep state. This eliminates the waiting period and enables real-time monitoring of battery current conditions.
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 quick and accurate measurement of parasitic draw without waiting for the vehicle to sleep, reducing the need for fuse replacements and minimizing downtime, while providing precise current readings even at low levels, thus effectively identifying and verifying parasitic draw.
Implementation Method 1
combines a multi-meter with a high-current electrical shunt, allowing direct measurement of up to 100 amps without needing to switch circuits, ensuring accurate readings and minimizing false positives by using a specific resistance shunt
Implementation Method 2
The first is the use of an 'amp clamp' which is a device that is installed around a cable and can measure the magnetic field generated by current flowing through the cable. From this it can calculate the amount of current flowing through the cable.
Data Source
AI summary
An automotive battery draw monitor for monitoring the parasitic draw on an automotive battery. The invention uses a shunt and a multi-meter to measure the voltage drop between the negative battery terminal and the negative battery cable. The invention is contained within a housing and powered via a power cable that connects the multi-meter to the positive terminal of the battery. The invention is grounded using a ground wire connected to the shunt.