Deep-cycle batteries

Global Electric Motor s two-seat GEM car is a NEV, with a top speed of 25 mph and a curb weight of 1100 pounds with batteries. A 72-volt shunt GE motor is used with front wheel drive. Six 12-volt deep-cycle batteries are used with hydraulic brakes, independent front wheel suspension, rack and pinion steering, aluminum welded space frame and composite and thermoplastic body. It seats two or four with a price of 7,000 to 9,000. 

Rubber separators have good voltage characteristics, the ability to retard antimony transfer, properties to retard dendrite growth, and good electrochemical compatibility. Due to the hydrophilic properties of the rubber composition, the separators are highly wettable and renewable for the dry-charging process. Paik et al. showed that AGE-SIL (sulfur cured, hard rubber) separators performed well in industrial stationary or traction batteries. FLEX-SIL (electron-beam-cured. flexible rubber separator) separators are suited for deep-cycling batteries, and MICROPOR-... 

Deep-cycle batteries store and deliver energy for motive power applications, such as golf carts, forklift trucks, and airport service vehicles. Use of batteries to... 

The major types of lead-acid batteries are SLI batteries, deep-cycle batteries, stationary batteries, and VRLA batteries. 

SLI batteries are not suitable for deep discharge functions like a deep-cycle battery is and vice versa. An SLI battery will not last in deep cycle because the thin sponge-like plates would quickly dissolve with repeated deep cycling. Combination starter/deep-cycle batteries are available for trucks, buses, and public safety and military vehicles, but these units are big and heavy. Table 1.13 compares the typical life of starter and deep-cycle batteries when deep cycled [6]. 

Deep-cycle batteries require good cycle life, high energy density, and low cost. The cycle life of a deep-cycle battery is usually longer than that of an SLI battery. The longer cycle life is achieved in the following manner ... 

Deep-cycle batteries are built for maximum capacity and high cycle count. The manufacturer achieves this by making the lead plates thick. Although designed for cycling, full discharges still cause stress, and longevity correlates to cycle count and... 

Cycle Performance of Starter and Deep-Cycle Batteries... 

Note Starter batteries and deep-cycle batteries cannot be interchanged. 

Figure 8.13 illustrates the Spectro CA-12 handheld battery tester. Battery test devices using this technology are being deployed to test starter and deep-cycle batteries. Having the ability to make capacity estimations helps in more accurately evaluating a battery and determining its end of life. 

Many types of automobile vehicles (see examples in Figure 10.5) use lead-acid batteries either for SLI purposes or engine powering. The first type of application uses SLI batteries, and the second type uses deep-cycle batteries. Both SLI batteries and deep-cycle batteries use exactly the same chemistry for their operation. The difference between them is mainly their design. 

In contrast, deep-cycle batteries are designed to provide a steady amount of current over a long period of time for power electric and/or hybrid electric vehicles. Because a deep-cycle battery acts as an engine s power function, it should be designed to be deeply discharged over and over again. To accomplish this, a deep-cycle battery uses thicker plates than a SLI battery. One of the most important requirements for deep-cycle lead-acid batteries is cycle life. 

Some small deep-cycling batteries feature tar (asphalt)-sealed cases and individual ceU covers. Here the tar seal allows easy repair to the battery. TraditionaUy aU batteries were made this way before about 1960, but heat seals are typical for SLI batteries today. Molten tar is dispensed from a heated kettle to fill a groove befween fhe cover and fhe case. The tar must be hot enough to flow easily but cool and viscous enough to soUdUy before ranning down into the cell. 

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