Batteries portable equipment

The portable equipment market usually needs to turn off any temporarily unused circuits to extend its battery life. In this case, a simple series MOSFET switch can be used. The RDS(ON) should be as low as possible to minimize the power dissipation within the MOSFET switch. These approaches are shown in Figure 3-58. 

Batteries for portable equipment 2 Wh-100 Wh Flashlights, toys, power tools, portable radio and television, mobile phones, camcorders, lap-top computers... 

The superior watt hours kg-1 offered by fuel cells (see Fig. 13.52) must again not be taken as a threat to batteries. The realm of effectiveness of batteries encompasses situations where it would be impractical to store fuel to make electricity on the spot. Such situations are widespread, particularly in powering portable equipment, from telephones to tape recorders. 

Consuming patterns have over recent years seen a dramatic increase in the use of portable equipment for entertainment and work (such as music and video players, laptop computers and mobile phones with multi-functionality). This has increased the demand for batteries, but at the same time found limitations of the battery technology that seem difficult to avoid even with increasing conversion efficiencies. Fuel cells with small-scale stores are an obvious solution to these problems, because the technical performance is already far beyond that of batteries (e.g., operating a state-of-the-art laptop computer for a few days rather than a few hours). The difference between these otherwise similar technologies is the external storage of chemicals for a fuel cell versus the internal storage in batteries. 

CD player will need less than 20 W. More specialised portable equipment includes field environmental monitors, medical mobile life-support systems and soldier commvmication and signalling devices used in military operations (Palo et al, 2002). Power requirements for such equipment would be in the range of 10-400 W. A standard size Li ion battery has a storage capacity of 750 mAh, and the largest one convenient for a laptop computer has a capacity of 3600 mAh. For a portable video camera, the standard Li ion battery may deliver 5 W at 7 V for about 1 h, while for the laptop at 12 V, the larger battery provides about 4 h at an average power consumption of 10 W. 

From the analysis of the results of this study, it is concluded that for portable rechargeable batteries associated to electrical and electronic equipment, the annual quantity available for collection represents only a minor percentage of the annual acquisition rate, representative of market sales. Both rates vary with the type of equipment, consequently there is no direct relation between the quantities of batteries and equipment introduced into the market and the quantities that the consumer is ready to eliminate either by participating to a collection scheme or by discarding the battery or the equipment in the MSW stream. 

The drive to reduce the size of conventional instrumentation has come about from a need to take equipment out of the laboratory to the sampling site. This requires an instrument that can be transported easily and that can work in the field, ideally from batteries for at least a few hours. The batteries may be disposable or rechargeable. Some portable devices have the option that they can work from mains electricity consequently, they can also be used back in the laboratory, where they save space due to their smaller footprint and often cost less to run and maintain than their benchtop counterparts. Where equipment may need to be moved from one location to another, even for coupling to another instrument, a smaller footprint and portability is again advantageous. Compact instruments usually require less sample and reagent volumes, which in turn reduces waste. Often, portable equipment is more user-friendly than the benchtop version as it is designed for use by nonscientists as well as scientists. 

In 1882, the city of Paris installed a system for the distribution of electricity for lighting comprising a combination of dynamos and lead—acid batteries. The first electrically lit street was Grands Magasins du Louvre in Paris ( the city of lights ). In 1883, Plante supplied the Imperial Palace of Franz Josef in Vienna with stationary and portable equipment for lighting. 

Kureha Corporation has developed nongraphitizable carbons (so-called hard carbon) prepared from the cross-linked petroleum pitch for almost 20 years as an anode of the lithium-ion battery (LIB). However, in these years graphite is more popularly used as an anode of LIB of small portable equipment, such as cellular phones, digital cameras, and portable personal computers, because high-energy density is much more important in this type of application than long-life durability is. Hard carbon has been used only in the field of professional camcorders, satellites, and electric bikes because it seemed to be difficult to change a new battery at the end of its life. 

Commercial Lithium-Ion Battery Packs for Portable Equipment.388... 

This Chapter discusses the nature of commercial lithium-ion battery packs used for portable equipment in Section 2, limitations of commercial lithium-ion cells in Section 3, quality control of commercial lithium-ion cells in Section 4 and the commercial li-ion cells and battery pack safety certification process in Section 5. 

Most original equipment manufacturers (OEMs) choose at least two commercial cell vendors for each unique piece of equipment to meet the supply and demand. Although the user can rarely determine the source of the Li-ion cells in their OEM portable equipments, the OEM has stringent traceability requirements. The same cannot be said for after-market portable equipment batteries. This will be discussed in more detail in Section 4. 

Most commercial Li-ion batteries powering portable equipment are required to function for 2-3 years only, although maintenance and proper usage have allowed their use for up to 8 years in some NASA-JSC applications on the International Space Station (ISS). 

Battery safety has been obviously given a special attention in this volume. Commercial lithium-ion cells and batteries are commonly used to power portable equipment, but they are also used to buildup larger batteries for ground (e.g. EVs), space and underwater applications. Chapter 17 provides test data on the safety of commercial lithium-ion cells and recommendations for safe design when these cells are used in much larger battery configurations. Chapter 18 focuses on safety aspects of LIBs at the cell and system level. In particular, abuse tolerance tests are explained with actual cell test data. Furthermore, internal short and lithium deposition occurring in lithium-ion cells and failure mechanism associated with them are discussed. In Chapter 19, the state of the art for safety optimization of all the battery elements is presented. This chapter also reports tests on not yet commercialized batteries, which pass all the security tests without the help of a BMS. 

Another commonly used chemistry is the sealed lead-acid battery. The flooded version is found in automobiles, but most portable equipment use the sealed version, also referred to as gelcell or SLA. 

Before the development of batteries for electric vehicles considerably changed the situation, the available lithium-ion batteries tended to have a small capacity around 1 Ah to a few tens of Ah depending on the manufacturers. Therefore, it was necessary to connect the elements in series and in parallel to increase the voltage and capacity. These assemblies were made by intermediary companies, re-selling battery packs for portable equipment or for small autonomous systems. Today, manufacturers and companies specializing in connectics are working to develop methods of assembly and connection which offer the best performances of the pack. The assembly is of crucial importance to ensure the perennity of the performances over time (choice of connectors, management methods) and to make the battery safe (inclusion of fiises", etc ). 

The nickel-cadmium battery was an improvement with a lifetime increased to about 25 years. Small Ni-Cd batteries proved to be very useful during the 1980s in connection with the dramatic development of battery-driven equipment such as video cameras, shavers, portable computers, mobile telephones, and so on. Cadmium is such an environmental problem that great demands were made for ecofriend-ly alternatives. 

The most important performance indicators for power supplies designed for portable equipment are the specific energy per unit mass (weight), Ym (in J/kg) and/or per unit volume, Yi> (in J/L). Often, miniplants with fuel cells are used in portable equipment as a replacement for lithium-ion batteries, which have specific performance indicators of 150 Wh/kg and 350 Wh/L. 

The standardization of batteries started in 1912, when a committee of the American Electrochemical Society recommended standard methods of testing dry cells. This eventually led to the first national publication in 1919 issued as an appendix to a circular from the National Bureau of Standards. It further evolved into the present American National Standards Institute (ANSI) Accredited Standards Committee CIS on Portable Cells and Batteries. Since then, other professional societies have developed battery related standards. Many battery standards were also issued by international, national, military, and federal organizations. Manufacturers associations, trade associations, and individual manufacturers have published standards as well. Related application standards, published by the Underwriters Laboratories, the International Electrotechnical Commission, and other organizations that cover battery-operated equipment may also be of interest. 

The use of batteries is increasing at a rapid rate, much of which can be attributed to advancing electronics technology, lower power requirements, and the development of portable devices which can best be powered by batteries. Other conttibuting factors are the increased demand for battery-operated equipment, the opening of many new areas for battery applications ranging from small portable electronic devices to electtic vehicles and utility power load leveling. 

Portable Applications. This is a rapidly expanding area as many new portable devices are being introduced which are designed to operate only with batteries or, in some instances such as laptop computers, to operate with either batteries or AC line power. Both primary and secondary batteries are used in these portable equipments depending on service Ufe and power requirements, convenience, cost and other factors discussed in Sec. 6.4. 

Alkaline (Zn/alkaline/MnOj) Most popular general-purpose premium battery good low-temperature and high-rate performance moderate cost Most popular primary-battery used in a variety of portable battery operated equipments... 

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