Standby batteries, lead acid

The case is the largest portion of the container. The case is divided into compartments which hold the cell elements. The cores normally have a mud-rest area used to collect shed soHds from the battery plates and supply support to the element. Typical materials of constmction for the battery container are polypropylene, polycarbonate, SAN, ABS, and to a much lesser extent, hard mbber. The material used in fabrication depends on the battery s appHcation. Typical material selections include a polypropylene—ethylene copolymer for SLI batteries polystyrene for stationary batteries polycarbonate for large, single ceU standby power batteries and ABS for certain sealed lead—acid batteries. 

The world market for batteries of all types now exceeds 100 billion. Over half of this sum is accounted for by lead-acid batteries - mainly for vehicle starting, lighting and ignition (SL1), and industrial use including traction and standby power, with about one-third being devoted to primary cells and the remainder to alkaline rechargeable and specialist batteries. 

Stationary battery (cell) — Rechargeable -> batteries designed to be located at a fixed place. Stationary batteries are used mainly for uninterruptible power supplies (UPS) and standby applications. These cells are usually designed for high reliability and very long -> cycle life under shallow depth of discharge (DOD) conditions. The common chemical systems utilized for the production of stationary batteries are the -> lead-acid and -> nickel-cadmium batteries. Less common, and more futuristic is the - sodium-sulfur battery designed for KW and... 

Different types of lead-acid batteries have been developed as energy sources for many power applications, like traction and backup or standby power systems. The flooded lead-acid batteries have an excess or flooded electrolyte and they were the largest used at the beginning of the last century for many applications. Valve-regulated lead-acid (VRLA) batteries were developed as an alternative to the flooded lead-acid batteries, in order to maintain levels of distilled water and prevent drying of cells, which means safe operation for battery packs in electric... 

Lead-acid batteries will continue to have, by far, the major share of the standby battery market, due to their outstanding specific-energy, life and cost characteristics. It is expected that there will be a significant growth of the standby battery market during the next few years. Most standby batteries already have the valve-regulated... 

Sealed lead-acid batteries are in both cylindrical and prismatic shapes. The cyclindrical ones (usually designed as SLA batteries) have excellent high-rate characteristics. Other than in portable devices, sealed batteries can be used in standby applications, e.g. telephone exchange stations, were they are kept in float charge. In this case too, oxygen recombination is possible. 

An example of polymer additive to electrolyte is FORAFAC 1033D (polyfluoroalkyl sulfonic acid). Addition of FORAFAC 1033D in a concentration of 0.1 wt% to the electrolyte immobilized in AGM VRLA batteries leads to a major improvement of battery cycle life [49]. Standby batteries containing FORAFAC have improved their service bfe by a factor of 1.5, suffering smaller water loss and reduced self-discharge. 

Lead—acid batteries are used in three main applications automotive (starting, lighting and ignition, SLI), for motive power and for standby (reserve) power. A fourth type of lead—acid batteries is trying to gain a market segment, too, i.e. batteries for hybrid eleetric vehicle applications. In view of the partieular battery funetion and the speeifieity of the operation mode in the above four applications, the amounts of the three expander eomponents should differ for the different battery types, depending on their effeet on the proeesses that oeeur in the battery. Boden [39] proposes typical expander formulations for the different battery applications as summarised in Table 7.3. 

Lead/acid batteries are used for many diverse remote and standby duties and hence are manufactured with a wide range of voltage and current capabilities and capacities. Pb/acid batteries do self-discharge slowly because of some reaction between the active materials and water as a result the batteries are often on constant trickle charge. 

Lead-acid batteries are also used for emergency power in uninterruptible power systems (UPS), telecommunications back-up systems, and safety equipment in critical applications such as hospitals and nuclear power plants. Stationary or standby battery designs and recharge profiles vary according to the specific system requirements. Large battery strings are connected in series to deliver up to several hundred volts. 

Emergency power supplies involve standby rechargeable batteries traditionally of the lead-acid accumulator type with vulcanised rubber cases and cellulosic separators. 

Nevertheless, in very critical cases - e.g., nuclear power station - mostly vented lead-acid cells and batteries will also in future be used as standby, because of the better ability for controlling and monitoring, which are important safety aspects. 

The three major types of nonautomobile applications in which lead-acid batteries play important and necessary roles are (1) stationary applications for large-scale electricity storage (2) standby applications for UPS, telecommunications, and emergency lighting and (3) backup power applications. 

A backup lead-acid battery system, unlike a standby battery system, normally does not have the function of automatic outage detection. With a backup power system, when utility power fails, the user usually must start the battery system manually by connecting extension cords directly from the backup battery to the appliance to be powered. Note that all of the battery systems discussed in the standby power applications section can be used as backup systems. In addition, there are several other small-scale applications such as engine starting for portable generators, cable TV applications, cordless power tools, portable printers, battery-powered camping equipment, handheld home devices such as vacuums and razors, and medical equipment. 

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