Traction cells

Flooded traction cell with tubular plates (350 Ah at 5 hour rate). 

Table 2.4 Lead acid traction cells with tubular plates, series L, dimensions conforming to lEC 60 254 2. 

A parallel new standard, DIN 43 598, is in preparation Part 1 for small traction batteries with positive tubular plates in monoblocs corresponding to DIN 43 594. Part 2 for small traction cells in plastic trays. (See Tables 2.6 and 2.7.)... 

A further possibility to increase the performance of lead-acid traction cells is electrolyte circulation, as proved in batteries for electric road vehicles and batteries for submarines. The principle is an airlift pump installed in each cell. The results are... 

Figure 2.10 shows a modern lead-acid traction cell designed by Varta with electrolyte circulation compared to a cell with electrolyte stratification. There are many electrochemical systems that will yield favorable accumulators (see Chapters 1 and 10), some of which have reached a very promising state of development. They will have to prove their versatility in practical application, especially with the aspect of economy in the future. 

Figure 4.9 Development of energy density (percent Wh/kg) of lead acid traction cells with future outlook.

Testing standards include testing methods for type and acceptance tests. Example DIN 43539, part 3 titled Lead-acid accumulators test methods, traction cells and batteries. ... 

DIN 43 539, Part 3 Lead-acid accumulators Test methods, traction cells and batteries. Harmonized (see EN 60 254-1). 

Figure 17.12 indicates this situation at 350 Ah for traction cells. In all cases the electrolyte had a gravity of 1.23 g/cm. It is obvious that in the flooded cell even after... 

Epoxy glue seal An epoxy glue seal employs either solvent cement or a thermal seal. These types of seals are often used for stationary batteries and traction cells so that coolant can be circulated through the terminals. 

Industrial traction ceUs and old-style SLI cells have been connected into batteries after the cell cases and covers are sealed together. Traction batteries are needed in thousands of different sizes for various applications, and the standard unit of construction is a cell, not a quantity of plates and separators. A heavy steel tray is fabricated and coated with an acid-resistant coating (urethane, epoxy, etc.). Traction cells are placed into the tray and shimmed as necessary, and interceU connections are welded on. Heavy flexible wires (made from welding cable) are welded to the end cells for connection to the external circuit. 

Military submarines of the diesel-electric type require cycling batteries for propulsion. These batteries are made with nonantimonial lead grids because stibine and arsine produced on charge are unacceptable for personnel health in a closed environment. The plates are much larger than most traction cells—up to 600 cm wide and up to 1500 cm tall. Both flat-pasted and tubular positive plates are used. 

Traction or motive-power batteries are made in many different sizes, limited only by the battery compartment size and the required electrical service. The basic rating unit is the positive-plate capacity, given in Ampere-hours at the 5- or 6-h rate. Table 23.14a lists the typical U.S. traction plate sizes using flat-pasted plates between 5 and 33 plates are used to assemble traction cells, as also shown in the table. Ratings of the cell are the product of the capacity of a single positive plate multiplied by the number of positive plates. The cells, in turn, are assembled in a variety of battery layouts, with typical voltage in 6-V increments (e.g., 6, 12, 18 to 96 V) resulting in almost 1000 battery sizes. Popular traction battery sizes are the 6-cell, 11-plates-per-cell, 75-Ah positive-plate (375-Ah cell) and the 6-cell, 13 plates-per-cell, 85-Ah positive-plate (510-Ah cell) batteries. Table 23.146 presents similar information on the tubular positive-plate batteries. 

Typical dimensions for the /5-alumina electrolyte tube are 380 mm long, with an outer diameter of 28 mm, and a wall thickness of 1.5 mm. A typical battery for automotive power might contain 980 of such cells (20 modules each of 49 cells) and have an open-circuit voltage of lOOV. Capacity exceeds. 50 kWh. The cells operate at an optimum temperature of 300-350°C (to ensure that the sodium polysulfides remain molten and that the /5-alumina solid electrolyte has an adequate Na" " ion conductivity). This means that the cells must be thermally insulated to reduce wasteful loss of heat atjd to maintain the electrodes molten even when not in operation. Such a system is about one-fifth of the weight of an equivalent lead-acid traction battery and has a similar life ( 1000 cycles). 

A second type of cytokinesis has come to light in mutants of Dictyostelium lacking mysoin-II. These cells are able to crudely separate by traction mediated cytokinesis, a process by which the bi- (or multi-) nucleate cells tear themselves apart in an attempt to crawl in two opposite directions. 

The acellular structure of real bone is modified continuously according to the internal stresses caused by applied loads. This process, which represents an attempt to optimize the strength-to-weight ratio in a biological structure, is achieved by the interaction between two types of cell, one that absorbs bone and the other that synthesises new bone. New bone is added where internal stresses are high, and bone is removed where stresses are low. An accurate finite-element model of this combined process could be used clinically to determine the course of traction that will maximise bone strength after recovery from a fracture. 

Suter DM, Forscher P. Transmission of growth cone traction force through apCAM-cytoskeletal linkages is regulated by Src family tyrosine kinase activity. J Cell Biol 2001 155(3) 427-438. 

High power primary zinc-air cells are also developed with nominal current 20A -v 40A and capacity in the range 100 Ah -v 320 Ah. Typical application of these powerful zinc-air cells is as easy activated reserve power supply. These cells also can be successfully used for traction. 

Fuel-cell stack Control of gas production Traction motor... 

Recently, the major activity in transportation fuel cell development has focused on the polymer electrolyte fuel cell (PEFC). In 1993, Ballard Power Systems (Burnaby, British Columbia, Canada) demonstrated a 10 m (32 foot) light-duty transit bus with a 120 kW fuel cell system, followed by a 200 kW, 12 meter (40 foot) heavy-duty transit bus in 1995 (26). These buses use no traction batteries. They operate on compressed hydrogen as the on-board fuel. In 1997, Ballard provided 205 kW (275 HP) PEFC units for a small fleet of hydrogen-fueled, full-size transit buses for demonstrations in Chicago, Illinois, and Vancouver, British Columbia. Working... 

On the other hand, since most of these reactions are thermally activated, their kinetics are accelerated by the rise in temperature in an Arrhenius-like manner. Therefore, within a much shorter time scale, the adverse effect of these reactions could become rather significant during the storage or operation of the cells at elevated temperatures. In this sense, the long-term and the thermal stability of electrolytes can actually be considered as two independent issues that are closely intertwined. The study of temperature effects on electrolyte stability is made necessary by the concerns over the aging of electrolytes in lithium-based devices, which in practical applications are expected to tolerate certain high-temperature environments. The ability of an electrolyte to remain operative at elevated temperatures is especially important for applications that are military/space-related or traction-related (e.g., electric or hybrid electric vehicles). On the other hand, elevated tem-... 

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