Battery’ selection, primary batteries

Table 6.7 illustrates the selection of primary and secondary batteries. As the power requirements of the application increase (going from the bottom of the list to the top) and the size of the battery becomes larger, the trend for the battery-of-choice shifts from the primary to the secondary battery. The primary battery dominates in the lower power applications and where a long service life is required, such as smoke detectors, implants and memory backup. 

Lead Telluride. Lead teUuride [1314-91 -6] PbTe, forms white cubic crystals, mol wt 334.79, sp gr 8.16, and has a hardness of 3 on the Mohs scale. It is very slightly soluble in water, melts at 917°C, and is prepared by melting lead and tellurium together. Lead teUuride has semiconductive and photoconductive properties. It is used in pyrometry, in heat-sensing instmments such as bolometers and infrared spectroscopes (see Infrared technology AND RAMAN SPECTROSCOPY), and in thermoelectric elements to convert heat directly to electricity (33,34,83). Lead teUuride is also used in catalysts for oxygen reduction in fuel ceUs (qv) (84), as cathodes in primary batteries with lithium anodes (85), in electrical contacts for vacuum switches (86), in lead-ion selective electrodes (87), in tunable lasers (qv) (88), and in thermistors (89). 

Owing to possible future restrictions that could preclude the testing of samples with all five toxicity tests, we evaluated the index response with a reduced battery of toxicity tests. The basic rule for the selection of tests in a reduced battery was to maintain one primary producer, one primary consumer and a secondary consumer. The test combinations of two selected reduced batteries were Hydra, Daphnia and Lactuca tests (H-D-L) and Hydra, Daphnia and S. capricornutum (H-D-S) tests... 

Primary Batteries, Selection and Application, Table 1 Qualitative comparison of primary battery types (1 to 7 where 1 is best) ... 

Table 1 gives some general characteristic rankings of primary battery types that should be of help in narrowing the selection of a battery. 

Figure 18.1 and Table 18.1 give an overview on the wide variety of lithium primary systems which have been at least temporarily introduced into the market. This variety gets remarkably wider if one takes into account also all those systems which were tested on the laboratory scale but not fully developed for practical applications. A small selection of lithium primary batteries which were successful in their special markets shall be described in detail here to show some design and building principles. 

None of the rechargeable batteries summarized in this table possesses the same degree of the principal characteristics that are essential in a rechargeable battery. In the case of primary batteries, the user can make select a battery to satisfy requirements for cost, recharging facilities, continuous or intermittent use, and low- or high-temperature application. 

The special and reserve primary batteries are used in selected applications usually requiring batteries which are capable of high-rate discharges for short periods of time after long-term storage in an inactivated or reserve condition. Many of these are used by the military for munitions and missiles. 

With data of this type, it is possible to make a start in the process of selecting a suitable type of secondary battery to meet a particular application. However, as discussed in Section 2.1 on primary batteries, many other considerations would apply in making the final selection. 

In conclusion, it can be said regarding the battery selection process, whether primary or secondary batteries are being considered, that the design engineer is faced with many commercial portable power systems in a wide variety of models. The battery selection process cannot therefore be reduced to an exact science. Seldom does any one battery system meet all the requirements Ta a given application. The selec-lion of a battery is further complicated by the fact that the performance characteristics of battery systems vary with temperature, current drain, service schedules, etc. Consequently the selection process usually involves a trade-off or compromise between battery requirements and battery system characteristics. 

Container. The battery container is made up of a cover, vent caps, lead bushings, and case. Cost and appHcation are the two primary factors used to select the materials of constmction for container components. The container must be fabricated from materials that can withstand the abusive environment the battery is subjected to in its appHcation. It must also be inert to the corrosive environment of the electrolyte and soHd active materials, and weather, vibration, shock, and thermal gradients while maintaining its Hquid seal. 

EGSG Idaho s Idaho National Engineering Laboratory reviewed Licensee Event Reports (LERs), both qualitatively and quantitatively, to extract reliability information in support of the USNRC s effort to gather and analyze component failure data for U.S. commercial nuclear power plants. LERs describing failures or command faults (failure due to lack of needed input) for selected components have been analyzed in this program. Separate reports have been issued for batteries and battery chargers, control rods and drive mechanisms, diesel generators, ISC, Inverters, primary containment penetrations, protective relays and circuit breakers, pumps, and valves. 

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