Inductive Battery Pack Heating for Cold Weather Charging
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Lithium-based battery cells in power tools and outdoor devices face challenges in maintaining capacity and performance when charged in cold weather conditions, as charging below a certain temperature threshold can cause damage or reduce efficiency.
Innovation Solution
An inductive heater assembly using Helmholtz coil windings and a charging base to heat battery packs before charging, ensuring the temperature exceeds the charging threshold, utilizing active or passive resonator controls to manage electromagnetic fields for efficient heating.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If lithium-based battery cells are charged in cold weather conditions below the temperature threshold, then the device can operate in adverse environments, but the battery capacity and performance are compromised and damage may occur
Solution Approach 1:
The system performs preliminary heating of the battery pack using Helmholtz coils before initiating the charging process. Temperature sensors detect when the battery temperature is at or below the charging threshold, and the control circuit activates the heating coils to raise the temperature above the threshold before charging begins, ensuring safe charging conditions in cold environments
Solution Approach 2:
The Helmholtz coils serve as an intermediary heating mechanism between the cold environment and the battery pack. The coils generate an electromagnetic field that induces eddy currents in the battery pack's metal housing, which then heats the battery internally through resistive heating, providing controlled thermal management without direct thermal contact
2Temperature
If the battery pack is heated using traditional heating elements, then the temperature can be raised above the charging threshold, but the device complexity and energy consumption increase
Solution Approach 1:
The system replaces traditional mechanical heating elements with an electromagnetic induction heating system using Helmholtz coils. The coils generate a time-varying magnetic field that induces eddy currents in the battery pack's conductive housing, which then generates heat through electrical resistance, eliminating the need for direct thermal contact heating elements
Solution Approach 2:
The system changes the physical state and properties of the heating mechanism from thermal conduction (traditional heaters) to electromagnetic induction. By adjusting the frequency and amplitude of the alternating current through the Helmholtz coils, the system can precisely control the heating rate and temperature achieved, optimizing the heating process
3Productivity
If the battery pack is heated quickly to enable immediate charging, then the productivity is improved, but the temperature control precision may be compromised
Solution Approach 1:
The system incorporates temperature sensors that continuously monitor the battery pack temperature and provide feedback to the control circuit. The control circuit adjusts the power delivered to the Helmholtz coils based on the temperature feedback, increasing power when heating is needed and reducing or stopping power when the threshold is reached, ensuring precise temperature control while maintaining quick response
Solution Approach 2:
The heating process uses periodic alternating current through the Helmholtz coils at specific frequencies that resonate with the battery pack's electrical properties. This periodic electromagnetic action efficiently generates heat through induced eddy currents while allowing for rapid on/off control to achieve quick heating without overheating
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
Ensures safe and efficient charging of lithium-based battery packs by heating them to the required temperature, maintaining performance and capacity, and preventing damage from cold weather charging.
Implementation Method 1
a coil winding operable to receive power from the circuit and generate a magnetic field to heat the battery pack
Implementation Method 2
An inductive heater assembly using Helmholtz coil windings and a charging base to heat battery packs before charging
Data Source
AI summary
An inductive heater assembly for heating a power tool battery pack, the inductive heater assembly comprising a housing, a battery pack interface configured to receive the power tool battery pack, a charging base, a coil portion located within the housing. The coil portion including a first coil winding and a second coil winding configured to generate an electromagnetic field, wherein the first coil winding and the second coil winding to form a Helmholtz coil.