1、Vehicle Battery Fires Why They Happen and How They HappenOther SAE books of interest: Simulation, Modeling, and Analysis of Batteries By John Turner (Product Code: PT-176) Automotive 48-volt Technology By Johneric Leach (Product Code: JP-ABOUT-001) Lithium-Ion Batteries in Electric Drive Vehicles By
2、 Ahmad A. Pesaran (Product Code: PT-175) For more information or to order a book, contact: SAE International 400 Commonwealth Drive Warrendale, PA 15096, USA Phone: 1+877.606.7323 (U.S. and Canada only) or 1+724.776.4970 (outside U.S. and Canada) Fax: 1+724.776.0790 Email: CustomerServicesae.org Web
3、site: books.sae.orgVehicle Battery Fires Why They Happen and How They Happen Gregory Barnett Warrendale, Pennsylvania, USA Copyright 2017 SAE International eISBN: 978-0-7680-8359-0400 Commonwealth Drive Warrendale, PA 15096 USA E-mail: CustomerServicesae.org Phone: +1 877.606.7323 (inside USA and Ca
4、nada) +1 724.776.4970 (outside USA) Fax: +1 724.776.0790 Copyright 2017 SAE International. All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, distributed, or trans- mitted, in any form or by any means without the prior written permission of SAE Internat
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6、2016948859 Information contained in this work has been obtained by SAE International from sources believed to be reliable. However, neither SAE International nor its authors guarantee the accuracy or completeness of any information published herein and neither SAE International nor its authors shall
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8、are required, the assistance of an appropriate professional should be sought. ISBN-Print 978-0-7680-8143-5 ISBN-PDF 978-0-7680-8359-0 ISBN-epub 978-0-7680-8361-3 ISBN-prc 978-0-7680-8360-6 To purchase bulk quantities, please contact SAE Customer Service: Email: CustomerServicesae.org Phone: 1+877.60
9、6.7323 (inside USA and Canada) 1+724.776.4970 (outside USA) Fax: 1+724.776.0790 Visit the SAE International Bookstore at books.sae.orgAcknowledgments The author would like to thank Mr. Mike Eskra for his valuable assistance and expertise during the development of this publication. Mr. Eskra contribu
10、ted greatly to the accuracy of the text, and particularly to the battery chemistry material, with his extensive experience in battery manufacturing. His insightful review of the manuscript is greatly appreciated. Much appreciation, as well, to the following organizations for their technical advice,
11、assistance, and permission to reprint material and text used within the publication: Robert Bosch (America), Battery University, Manmac Corporation, General Motors Corporation, Chrysler, and Ford Motor Company. Finally, thanks are extended to Dr. Richard Kaner (UCLA of California) and his team for t
12、he contribution of microscopic photographs of graphene and a molecule being inserted into the graphene matrix. Without Dr. Kaners assistance, these images would not be included in this publication.vii Contents Acknowledgments v Introduction .xi Chapter 1: History of the Battery .1 1.1 Early Beginnin
13、gs and Experiments 3 1.2 The Lead-Acid Battery . 8 1.3 Early Lead-Acid Battery Designs . 10 References . 13 Chapter 2: Battery Designs . 15 2.1 Basic Concepts . 15 2.2 Elements of a Battery . 17 2.3 Lead-Acid Plate Designs 19 2.4 Insulator and Separator Design Issues 20 2.5 Valve Regulated Lead-Acid
14、 Designs 21 2.6 Gelled Electrolyte Lead-Acid Designs . 23 2.7 Absorbent (Absorptive) Glass Mat 24 2.8 Deep-Cycle Battery Designs . 26 2.9 Advanced Lead-Acid Battery Designs . 27 2.10 Dual Battery Technology for Hybrid and All-Electric Vehicles Using Stop/Start Technology . 29 2.11 Casing Design Cons
15、iderations for Forklifts and Heavy Equipment 29 2.12 Chemistry of the Lead-Acid Plate Design 31 References . 35 Chapter 3: Battery Location Design Issues 37 3.1 Importance of Battery Location for Early Designs . 37 3.2 Design Issues for Later Model Vehicles 38 3.3 Design Issues for Components Surrou
16、nding the Battery . 44 Chapter 4: Direct and Alternating Current 57 4.1 Generators and Alternators 57 4.2 Electron Flow 61 4.3 Battery Ratings 62 4.4 Failure Mode Differences between AC and DC Electricity . 63 4.5 Charging of a Lead-Acid Battery . 68 References . 74viii Contents Chapter 5: Lithium B
17、atteries75 5.1 Lithium Primary Batteries . 76 5.2 Lithium-Ion Thionyl Chloride Cell . 76 5.3 Lithium-Ion Perchlorate Manganese Oxide Cell 77 5.4 Lithium Tetrafluoroborate with Carbon Monofluoride Cathode 78 5.5 Lithium-Iron Disulfide 78 5.6 Lithium-Air Battery 78 5.7 Future Battery and Super-Capacit
18、or Designs . 79 5.8 Failure Characteristics and Issues 85 References . 89 Chapter 6: Nickel-Metal Hydride Battery 91 6.1 Hybrid Electric Vehicles . 92 References . 95 Chapter 7: Automotive Electrical Fire Science97 7.1 Automotive Fire Science Terms . 97 7.2 A Word about Safety . 97 7.3 FMVSS 302Inte
19、rior Flammability . 98 7.4 Society of Automotive Engineers Standard J369 . 100 7.5 Society of Automotive Engineers Standard J1344 100 7.6 Fire Analysis of a Vehicle 101 7.7 Electrical Fire Analysis . 109 7.8 Signs of Electrical Heat 112 References 208 Glossary .xv References xxii Index xxiii About t
20、he Author xxxixi Introduction The vehicle of today is as much electrical and electronic as it is mechanical. The “backyard mechanic” has been replaced with highly trained dealership technicians. Engineering demands are in a constant state of change. The wiring harness on the average vehicle has beco
21、me a large maze of wires routing throughout the vehicle. The rise in the use of electrical and electronic systems has come with a cost: The simple truth is that electrical fire is the most common type of fire occurring in automobiles. Reporting of fires to the National Highway Traffic and Safety Adm
22、inistration must occur within days of the auto manufacturer learning of the event or the manufacturer will risk incurring fines that can run into the millions of dollars. The first rule in fire analysis of automobiles and related products is that there are no absolutes. Electrical system failure mod
23、es vary widely and depend on many factors. Generally, for an electrical failure to cause a large fire, some type of fuel must be in the immediate vicinity of the failure. Still, if no fuel is available to help fire propagation, the electrical failure can still be cata- strophic. The vehicle may well
24、 be destroyed by smoke damage. However, with a nearby source of available fuel, the damage path will be far greater. Any investigating engineer or technician who has been assigned to troubleshoot the cause and origin of a fire can only respond according to their individual level of training and expe
25、rience. Troubleshooting is not a skill that can be taught in the classroom. It is a skill honed by many years of hands-on experience. Care should be exercised so that the investigation does not bend the facts to fit a given fire theory. Rather, the “big picture” should be examined in context with th
26、e evidence discovered. Because the topic of electrical fire is not a widely taught subject, the purpose of this book is to assist in the analysis with some understanding of the issues faced in electrical system design, battery construction, fault modes, etc. The investigating engineer should apply b
27、oth deductive and inductive reasoning to the analysis. The scientific method should not be discarded in an attempt to make a pet fire theory work. However, some fires have consumed the evidence to the point where a determina- tion cannot be made with any degree of certainty. In this instance, eviden
28、ce will be quite limited. Therefore, the analysis will have its limitations, and this fact should be included in the discussion. In some cases, a “cause undetermined” report is all that the evidence will support. The following is a brief history of the battery from the earliest cell discovered in an
29、tiq- uity to the modern lead-acid battery. Many more developments have occurred between inception and use in the modern automobile. Only the more notable developments are xii Introduction covered. A historical timeline is included to credit the inventors and innovators that added to the development
30、of the lead-acid battery. The more modern developments are discussed in later chapters. Greater focus is placed on the lead-acid battery, because this design is the most common in automobiles worldwide. The descriptions and basics of the battery are covered for readers unfamiliar with this specific
31、technology. Otherwise, you may wish to skip ahead unless you are a fan of history. Although many other important advances and developments were made to what would eventually be the battery used in modern automobiles, only the more notable advance- ments are discussed. The primary focus will be on di
32、fferences in failure modes between DC and AC systems, general types of battery and electrical failure modes leading to fire, how to interpret elec- trical fires, determination of the primary failed part, and other skills the investigating engineer will require to perform technical failure mode analy
33、sis.1 Chapter 1 History of the Battery The earliest example of a galvanic cell is the Baghdad Battery. The name comes from the collection of antiquities and artifacts in Mesopotamia during the Iranian dynasties of the Parthian period (approximately 250 BC to 250 AD). The artifacts are believed to be
34、 about 2000 years old 1-1. The Baghdad Batteries were discovered in a village called Khujut Rabu, near Baghdad. They are terracotta jars, each fitted with a rolled-up sheet of copper surrounding an iron rod. The iron rod is suspended in the tube and jar through an asphalt stopper. Figure 1.1 is a re
35、production of the Baghdad Battery 1-2. Although no instructions were found with the Baghdad Batteries regarding their use, simply filling the jar with vinegar or any other electrolytic solution will cause the battery to produce approximately 1.1 V DC for two hours. Scientists speculate that the devi
36、ces were used to electroplate one metal onto the surface of another, such as putting a layer of gold onto silver. This process is still in use in Iraq today. Some historical debate is ongoing as to the age of the Baghdad Batteries and the arche- ologist who discovered them. One account is that Germa
37、n archeologist Wilhelm Konig discovered them in 1938. However, the fact that the artifacts exist is proof of how long man has known how to generate electricity. Additionally, if the scientists speculation is correct, then man also learned how to use the electricity produced. 2 Chapter 1 Figure 1.1 C
38、utaway of the Baghdad Battery.3 On another historical note, there is mention in a book entitled Agastya Samhita (Sanskrit, India) authored by a revered sage of the day named Agastya. The writings describe the construction of a battery by placing copper plates into an earthen pot, and covering it in
39、copper sulfate and wet sawdust. Zinc powder is spread on the surface, and it is covered with mercury. Student reproduc- tions of this early cell report that the cell will produce approximately 1.4 V DC. Note that Sanskrit is one of many Pan-Asian languages that predate the scientific method and newe
40、r traditions in scientific documentation. 1.1 Early Beginnings and Experiments An early scientist to experiment with electricity is one of the United States founding fathers, Benjamin Franklin. He was the first to use the term “battery.” Benjamin Franklin used the term “battery” to describe a set of
41、 capacitors he devised and fastened together for his experiments in electricity. His capacitors were sheets of glass coated with metal on both sides 1-3. By connecting the capacitors together, he noted that the stored charge was “greater” when the assembly was discharged. Because volt- meters had no
42、t yet been developed, it is presumed that the spark produced by the capac- itors was visibly greater as the number of capacitors hooked in series was discharged. The term “battery” has the generic meaning of “an array of similar things intended for use together” 1-4. Benjamin Franklin thought that u
43、se of the term “battery” was most appropriate for his capacitor array because of the functioning similarities to an artillery battery. Thus, the term “battery” to refer to a collection of electrical devices was coined. In 1800, Alessandro Volta invented the first true battery that differed from the
44、galvanic cell design. In Voltas design, shown in Figure 1.2, he piled copper plates in pairs with zinc discs. The discs were piled on top of each other, each separated by a layer of cloth or cellulosic material. Brine was added to the jar containing the piled plates to create the first “voltaic pile
45、” battery. Volta continued experiments with various metals. Ultimately, he determined that zinc and silver gave off the greatest amount of current. Volta incorrectly believed that the current in his battery was the result of two different materials touching each other. This was an obsolete scientifi
46、c theory known as “contact tension.” Because of Voltas belief in contact tension, he regarded the corrosion that occurred in his zinc plates as some type of unrelated flaw. He believed this flaw could be corrected by changing the materials used.4 Chapter 1 Figure 1.2 Volta pile battery.5 While Volta
47、 was experimenting with his voltaic piles, he observed that the corrosion would occur on the zinc plate much faster as higher amounts of current were drawn through the plate. This negated the theory of contact tension. Rather, this suggested to Volta that the action of the corrosion was actually int
48、egral to the batterys ability to produce a current. This led to the rejection of Voltas contact tension theory in favor of the electrochemical theory. Voltas original pile model suffered from some technical issues. Two of the more common flaws the design experienced were the container leaking electr
49、olyte and the creation of short circuits due to the discs being stacked one on top of the other. The weight of the discs would compress the cloth insulators, allowing one disc to touch the other. This problem was solved by a Scottish scientist named William Cruickshank. His solution stacked the plates on end inside a long box. This became known as the “trough battery,” and was the start of what the modern automobile battery would come to resemble. The biggest problem early cells had was low lifespan. The batteries of the day were all “primary” batteries. They could pr
