Battery Gauging Method Using Impedance for Low-Temperature Accuracy
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Solution Overview
Problem
Existing battery management systems, such as those developed by Texas Instruments, are inaccurate at low temperatures, leading to erroneous battery-related information and potential device malfunctions or shutdowns due to power supply issues.
Innovation Solution
A gauging method for battery discharge-capacity that involves detecting temperature and using either internal impedance or voltage and output current to estimate capacity, depending on temperature conditions, employing a hybrid battery algorithm to ensure precise capacity estimation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the TI gauging technique is used to estimate battery residual discharge-capacity, then the estimation is accurate at normal temperatures, but the estimation becomes inaccurate and susceptible to erroneous judgments at low temperatures
Solution Approach 1:
The patent changes the estimation parameters based on temperature conditions. At low temperatures, it switches from using only voltage and current (TI technique) to using internal impedance as an additional critical parameter. The system detects temperature and adjusts the gauging methodology accordingly, incorporating impedance measurements to compensate for the degraded performance of voltage-based estimation in cold conditions.
Solution Approach 2:
The patent segments the temperature range into different zones (low temperature vs. normal temperature) and applies different estimation techniques for each segment. For low temperatures, it uses a specialized approach incorporating impedance detection, while for normal temperatures, it uses the standard TI gauging technique. This segmentation allows optimal performance across different operating conditions.
2Measurement precision
If multiple parameters (temperature, voltage, current, impedance) are detected and processed, then the battery discharge-capacity estimation accuracy is improved, but the system complexity increases
Solution Approach 1:
The patent implements a dynamic system that adapts its measurement and processing requirements based on operating conditions. The processing unit dynamically selects which parameters to measure and how to process them based on temperature detection. This dynamic adaptation reduces unnecessary measurements and computations under normal conditions while activating additional measurements only when needed (low temperature), thereby balancing accuracy requirements with system complexity.
Data Source
AI summary
A gauging method for a battery discharge-capacity corresponding to a temperature includes steps of detecting a temperature of a battery module of an electronic device according to a predetermined condition; detecting an internal impedance of the battery module and estimating the battery discharge-capacity of the battery module according to the internal impedance if the temperature meets the predetermined condition; and detecting an output current and a voltage of the battery module according to the temperature and calculating the battery discharge-capacity of the battery module according to the temperature, the voltage and the output current if the temperature does not meet the predetermined condition.