Battery Pack Preheating Control for Low-Temperature Fast Charging
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Solution Overview
Problem
Lead-acid batteries used in light electric vehicles (LEVs) face challenges in maintaining reliability in extreme temperatures and fast charging requirements, necessitating improved temperature management and charging strategies.
Innovation Solution
A battery system with a microcontroller-controlled heating mechanism, using pulse width modulation signals to manage heating and charging based on cell temperature, ensuring efficient temperature regulation and safe charging operations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If fast charging is performed in low temperature environments, then charging speed is improved, but battery deterioration accelerates and reliability decreases
Solution Approach 1:
The system performs preliminary heating of the battery cells before initiating fast charging when the temperature is below the first reference temperature. The heating element raises the battery temperature to an acceptable range, and only after the temperature condition is met does the system enable fast charging, thereby preventing temperature-related deterioration while maintaining charging speed
Solution Approach 2:
The system dynamically adjusts the charging strategy based on real-time temperature monitoring. When battery temperature is between the first and second reference temperatures, the system permits fast charging; when temperature drops below the first reference temperature, the system switches to heating mode; and when temperature exceeds the second reference temperature, the system reduces charging current, creating a dynamic response that optimizes both charging speed and battery safety
2Temperature
If heating power is supplied to battery cells, then cell temperature is improved for charging, but energy loss increases
Solution Approach 1:
The system uses the charging power itself to heat the battery cells through controlled current flow, rather than requiring a separate external heating source. The heating element converts electrical energy to thermal energy within the battery pack, and the charging process benefits from this self-generated heat, reducing overall energy loss by eliminating the need for separate heating energy input
3Productivity
If charging voltage is increased for fast charging, then charging speed is improved, but battery safety risks increase in extreme temperatures
Solution Approach 1:
The system continuously monitors battery temperature and charging current, and dynamically adjusts the charging voltage and current based on real-time feedback. When temperature approaches the second reference temperature, the system reduces charging current to prevent overheating and safety risks, while maintaining fast charging capability within the safe temperature range between the first and second reference temperatures
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 system effectively maintains battery performance by preventing rapid temperature changes and overcharging, enhancing reliability and usability in varying environmental conditions.
Implementation Method 1
supply heating power from the charger to the heating element
Data Source
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AI summary
Provided is a battery system including a battery management module, a battery module, and a controller. The battery management module includes a main switch between an external terminal and a battery terminal, and a heating switch between the external terminal and a heating terminal. The battery module includes a cell, a heating element, and a control switch connected to the heating element. The controller is configured to detect a connection with a charger, detect a temperature of the cell, when the temperature is lower than a first value, turn off the main switch and turn on the heating switch and the control switch to supply heating power from the charger to the heating element, and when the temperature becomes higher than a second value by the heating element, turn off the heating switch and turn on the main switch to supply charging power from the charger to the cell.