Fast-charge batteries

Su Yun 2009. Research of mine-used lead-add battery fast-charging device [D]. Anhui University of Science Technology. 

For instance, charging a 30 kWh battery in 10 minutes requires a minimum of 180 kW of power, equivalent to an office block. Fast charging, therefore, also poses a particular challenge to the battery-management system. 

Nickel-cadmium sealed cells are now a commercially important consumer product. They find use, both as button and cylindrical cells, in portable cordless appliances such as power tools, electric razors and photoflash apparatus, and increasingly in hybrid mains/battery equipment such as portable tape recorders, radios and television receivers. Many of these cells are readily interchangeable with primary batteries. In recent years, advances in design have increased recharge rates cylindrical cells with sintered electrodes can now be fast charged from full discharge at up to the C/l rate of 80% of capacity. 

Contrarily to Li-ion batteries, the supercapacitor application requires highly developed surface area carbons with micropores adapted to the size of the ions involved in the formation of the electric double layer. In this case, the additional presence of mesopores is crucial to fulfill the demand of fast charge propagation with a minimal time constant. It seems that the most suitable would be to increase the amount of mesopores in KOH activated carbons or to increase the microporosity of the essentially mesoporous template carbons. A further improvement of the materials could be a special carbon doping by the incorporation of heteroatoms able to provide useful pseudocapacitance effects. 

Clearly, Cl may not be a universal algorithm, but it would be interesting to see what cycle-lives could be achieved with this procedure on thicker-plate VRLA batteries, where the oxygen cycle is not as active as in the Optima and Genesis products. It should be noted that each product may require a unique approach, as design dictates maximum current levels and recharge times in VRLA products. This has been demonstrated in the Cominco ALABC work on fast charging of Optima (thin-plate) and Delphi (thick-plate) batteries [61]. 

The temperature inside an AGM battery increases during fast charging [77,78]. Tests have shown a significant increase in the temperature although, normally, this... 

Fig. 13.17. Fast-charging characteristics of a 12-V, 65-Ah AGM battery with current limit of 100 A and voltage of 14.40 V.

Li Jun 2009. Study on fast-charging technology for lead-acid batteries [D]. Sichuang Southwest Jiaotong Universtry. 

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