Automotive batteries design

Whereas automotive batteries have the majority of the market, other types of lead—acid batteries, such as sealed and small maintenance-free varieties, are making inroads into various appHcations. The automotive battery s operating environment has changed substantially in the last 10 years. Underhood temperature has risen and electrical loads have increased. This trend is expected to continue as car manufacturers reevaluate thek design strategies and objectives. Battery design is changing to meet these needs. 

The mass of lithium ion batteries allows the automotive chemist and design engineers to decrease the mass of the overall vehicle as well as increase the performance of the vehicle. They are much lighter than other rechargeable battery designs. Lithium ions are also a wise choice for automotive use because self-discharge is very low (5% per month vs. 30% for nickel-metal hydride [NiMH] batteries). 

The above considerations indicate that the distinction between traction batteries and automotive batteries will be less clear-cut in the future. The tasks, duties, and operating conditions of batteries in road vehicles will be diverse. Therefore, it may be useful to redefine what is meant by the term automotive battery . In this chapter, this term is used for batteries in road vehicles that are (i) not regularly recharged from an external electrical source but, rather, only from an on-board source, such as an ICE-alternator combination or a fuel cell, and are (ii) not designed for extended, full-electric vehicle propulsion (see, Fig. 12.2). 

Valve designs used in stationary batteries have proven to be satisfactory for VRLA automotive batteries, and valves with an ethylene-propylene-diene polymethylene (EPDM, an artificial rubber) lip packing appear to be particularly well suited. Most European vehicle manufacturers demand a separate valve for each cell and, for all valve outlets, a joint gas-collecting duct with a flame arrestor... 

The main benefits of AGM batteries in present-day automotive applications, as compared with flooded battery designs with the same outer dimensions, are (i) higher power capability (ii) improved cycling capability, e.g., as in taxis ... 

Changes to the architecture of the vehicle electric power system are expected to proceed in an evolutionary rather than a revolutionary manner. It is the intention of the automotive industry and its suppliers that the 42-V PowerNet [9,11] will be available for technical situations which require very high power demands. Due to cost considerations as well as to uncertainties with respect to the availability and reliability of newly designed components [35], modifications will be introduced stepwise only when really needed. This process is expected to last many years. Therefore, the long-term solutions to the problems of increased vehicle electric power demand, the implications for battery design and manufacturing, and the possible intermediate steps have all to be considered carefully by the battery industry. 

In summary, the VRLA battery will claim a significant portion of the future automotive battery market. Due to cost considerations, conventional designs will also continue to be used. On the other hand, since lead acid technology is limited in some applications, other electrochemical systems will also gain a share of the market. 

In summary, each of the four subsystems described above are critical in the automotive Li-ion RESS design as all operate and function in conjunction with the other subsystems. For instance, a battery design that has an effective thermal management... 

Puglia F, Cohen S, HaU J, YevoU V (2005) Very Large Lithium Ion Cell and Battery Designs. The 5th International Advanced Automotive Ultracapacitor Conference (AABC-05) Proceedings. Honolulu, Hawaii... 

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