1. Field of the Invention
The subject invention generally relates to battery packs, and more particularly relates to a tunable frangible battery pack system for use in a vehicle or other industrial equipment.
2. Description of Related Art
Battery packs have been used for numerous years in electric vehicles, such as automobiles, boats, aerospace vehicles, and within other industrial equipment applications. Many of the electrical systems used in these prior art vehicles and equipment are designed to minimize the possibility of short circuiting and to reduce the potential of voltage exposure to emergency responders and other people in the general public. Such precautions help to reduce the possibility of an electrocution or other injury due to high voltage encounters and situations. There have been many different attempts at providing an electric system that will disconnect electrical circuits due to a crash of a vehicle or high temperature situations in a vehicle or industrial equipment application. Many of these prior art systems will disconnect the battery from the circuits thus creating an open circuit and protecting any responders and other people from dangerous high voltage situations. Generally, these prior art disconnect systems for battery packs will disconnect when a predetermined force is applied to the vehicle or equipment or if a predetermined thermal event occurs within the circuitry of the battery and/or electrical system.
One of the prior art methodologies for disconnecting battery cells uses a conductor wire that is either welded or bonded to a battery cell and is capable of being broken when a mechanical force is applied thereto. However, one problem with these prior art systems is that the mechanical strength of the breakable conductors was excessive and did not allow for the conductor to break unless the most extreme forces or situations acted on the vehicle or industrial equipment. Therefore, the disconnecting of the power supply system from the electrical vehicle or equipment did not occur during all emergency situations as many designs originally called for. Furthermore, the prior art methodologies of wire bonding the conductors to the cells did not provide a consistent fusing current mechanism such that high thermal events would not break the conductor, thus leaving the equipment connected to circuits which may lead to electrocution and other injuries to users or responders to an accident scene. Other types of connecting wire conductors between battery cells and other equipment have been used, including various bonding techniques for smaller diameter wires, conductive epoxies for connection between a battery cell and a bus bar or collector plate, soldering techniques that include solders made of nickel, tin, copper, plated metals, low metal alloys, etc. Furthermore, other prior art methodologies have tried installation displacement connectors to connect the battery cell to a bus bar or collector plate, mechanical crimping or pressure crimping has also been used to connect battery cells to a bus bar. Furthermore, it should be noted that conductor materials used for prior art wire conductors include copper, gold, nickel, solder, indium, tin, aluminum, low melt alloys and the like.
However, there have been problems with the prior art disconnect systems and methodologies for an electrical system having a battery pack or like power source. Some of the problems of the prior art include having the conductors arranged between battery cells and a bus bar or the like connected via bonding techniques that give the conductors very high mechanical strengths that do not allow the conductor to break unless the most extreme situations occur such as very high forces or extremely high heat. Furthermore, many of these prior art methodologies for creating a disconnect system use high cost materials and high cost processes to create such systems thus increasing the manufacturing costs and overall price structure for the manufacturer.
Therefore, there is a need in the art for an improved frangible battery pack system for use in an electric vehicle or industrial equipment. Furthermore, there is a need in the art for a tunable frangible battery pack conductor that is capable of being made in various widths and connected via an ultrasonic wedge bonding process to allow for breaking and disconnecting of the battery pack from the electrical vehicle or industrial equipment at a predetermined force or predetermined thermal parameters. There also is a need in the art for a low cost and easy to manufacture methodology and apparatus for creating a tunable frangible battery pack system including aluminum conductor wires.