Battery Load Control for Lawn Mower Current Thresholds
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing battery-powered outdoor power equipment faces challenges in managing electric current thresholds to prevent battery overloading, which can lead to performance degradation or shutdowns, without compromising primary functions like vehicle movement.
Innovation Solution
A battery controller system that monitors current, voltage, and temperature thresholds, sending messages to a vehicle controller to adjust or disable secondary loads when thresholds are exceeded, ensuring primary functions are maintained by transitioning between power maps based on actual electric current levels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If the battery operates at high current to maintain performance, then power output is improved, but battery reliability deteriorates due to overloading and thermal stress
Solution Approach 1:
The system dynamically adjusts the electric current threshold based on real-time battery conditions (temperature, state of charge, age) rather than using a fixed threshold. This allows the battery to operate at higher currents when conditions permit while automatically reducing thresholds when thermal or chemical stress increases, thereby maintaining power output when safe while protecting reliability when stressed
Solution Approach 2:
The battery controller continuously monitors battery parameters (temperature, voltage, current) and adjusts the electric current threshold in response to these measurements. This feedback loop enables the system to respond to changing battery conditions, preventing overloading while maximizing power delivery during optimal operating conditions
2Reliability
If the battery shuts down when current thresholds are exceeded, then battery protection is improved, but productivity deteriorates due to operational interruptions
Solution Approach 1:
The system transitions to conservative power maps in advance when approaching threshold limits, rather than waiting for thresholds to be exceeded and then shutting down. This proactive adjustment of power delivery parameters prevents the need for shutdowns while still protecting the battery, maintaining operational continuity while ensuring protection
Solution Approach 2:
Instead of binary on/off shutdown behavior, the system dynamically transitions between different power maps with varying current thresholds. This allows gradual adjustment of power delivery to stay within safe operating limits while maintaining continuous operation, eliminating productivity losses from shutdowns
3Device complexity
If the system uses fixed current thresholds, then device complexity is reduced, but adaptability deteriorates due to inability to respond to changing battery conditions
Solution Approach 1:
The system changes the electric current threshold parameter based on measured battery conditions (temperature, state of charge, age) rather than using a fixed value. This allows the threshold to adapt to changing battery characteristics and environmental conditions, significantly improving adaptability while adding only moderate complexity through standard sensor integration and conditional logic
Data Source
AI summary
A lawn mower includes a drive wheel, a mowing deck including a cutting blade, a wheel motor operable to rotate the drive wheel, a cutting blade motor operable to rotate the cutting blade, and a battery system. The battery system includes a battery configured to power the wheel motor and the cutting blade motor and a battery controller communicably coupled to the battery. The battery controller includes one or more processors and memory storing instructions that, when executed by the one or more processors, cause the one or more processors to determine an electric current threshold for the battery, broadcast a message comprising the electric current threshold, compare an actual electric current of the battery to the electric current threshold, and adjust an operation of the battery system in response in response to determining that the actual electric current of the battery exceeds the electric current threshold for a predetermined amount of time.