Lithium Battery Solid State Switch for Starter Motor
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Solution Overview
Problem
Lead-acid starter batteries for internal combustion engines are heavy, bulky, have short cycle and calendar life, and are inefficient, especially in cold weather, requiring oversized capacity and complex electronic protection circuits that induce heat and space losses, and are prone to damage from over-charging and over-discharging.
Innovation Solution
Replacing lead-acid batteries with lithium-based cells, such as lithium iron phosphate, and using a solid state switching configuration with MOSFETs or IGBTs to control current flow, eliminating the need for protection circuitry and allowing for bidirectional current control, thus preventing over-charging and over-discharging, and providing compact and efficient power management.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If lead-acid batteries are used for starter applications, then the battery can provide sufficient current for starting, but the weight and size increase significantly
Solution Approach 1:
The patent changes the chemical composition parameter of the battery from lead-acid to lithium-based chemistry, which fundamentally alters the energy density and weight characteristics while maintaining the required power output for engine starting
Solution Approach 2:
The invention uses composite lithium-based materials (such as lithium iron phosphate cathode with appropriate anode materials) to create a battery system that achieves superior specific energy compared to conventional lead-acid batteries, thereby reducing weight for the same power capability
2Power
If lead-acid batteries are used for starter applications, then the battery can provide sufficient current for starting, but the volume and space requirement increase
Solution Approach 1:
The patent changes the chemical composition parameter of the battery from lead-acid to lithium-based chemistry, which fundamentally alters the energy density and volume characteristics while maintaining the required power output for engine starting
Solution Approach 2:
The invention uses composite lithium-based materials (such as lithium iron phosphate cathode with appropriate anode materials) to create a battery system that achieves superior specific energy compared to conventional lead-acid batteries, thereby reducing volume for the same power capability
3Reliability
If electronic protection circuitry is added to lead-acid batteries, then over-charging and over-discharging can be prevented, but heat losses and electrical losses increase
Solution Approach 1:
The patent replaces mechanical/electronic protection circuitry with solid-state switching devices that provide protection functions with minimal energy loss, using semiconductor-based control instead of traditional relay or contactor systems
Solution Approach 2:
The invention changes the operational parameters of the switching system to operate in solid-state mode rather than mechanical contact mode, reducing resistive losses and heat generation while maintaining protection functionality
4Reliability
If electronic protection circuitry is added to lead-acid batteries, then over-charging and over-discharging can be prevented, but the device complexity increases
Solution Approach 1:
The patent replaces complex electronic protection circuitry with simplified solid-state switching devices that provide the same protection functions through semiconductor-based control, reducing overall system complexity
Solution Approach 2:
The solid state switch performs multiple functions (current control, overcharge protection, over-discharge protection, and reverse polarity protection) through a single integrated device, eliminating the need for separate protection circuits
5Ease of operation
If relay or contactor is used to control battery terminals, then current flow can be controlled, but energy consumption increases due to continuous current requirement
Solution Approach 1:
The patent replaces relay or contactor systems with solid-state switching devices that control current flow without requiring continuous power for actuation, using electronic field-effect control instead of electromagnetic coil actuation
Solution Approach 2:
The solid state switch automatically controls current flow based on battery conditions without requiring external continuous power supply for control, making the system self-regulating and energy-efficient
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 lithium-based battery system reduces weight and size, increases cycle and calendar life, improves efficiency, and provides reliable cold-weather performance with reduced energy consumption and enhanced safety against battery damage, while simplifying the battery management system.
Implementation Method 1
a solid state switch placed in-line with the battery output power terminals, the solid state switch can be electronically controlled to open or close the current pathway leaving or entering the battery
Implementation Method 2
The invention is a lithium-based cell for starting such engines
Data Source
AI summary
Apparatus for increasing the efficiency of a starter battery for a starter motor of an internal combustion engine in a battery pack arrangement with one or more lithium based cells. The invention includes a solid state switching configuration for high powered battery systems for protecting against over-charging, over-discharging and short circuiting of batteries, especially starter batteries for internal combustion engines. The invention is also useful as a Deep Cycle battery.