Field experience with maintenance-free battery designs that incorporate thin tubular positives during electric-vehicle use

The Classic 25 cell and the 3ET205 monobloc are two of the most used lead/acid batteries for electric busesand vans. Both products are of thin tubular positive-plate design, developed in 1988 and since then used in hundreds of electric vehicles(EVs). The excellent specific energy and the relatively low weight makes it an ideal product for EVs. Eight years field experience invarious applications has proven the good performance and the superior cycle life. Encouraged by the positive field experience of this thintubular plate technology, CMP Batteries started the development of valve-regulated lead/acid batteries with this design. This paper describes,briefly, the construction and design of the cells and monoblocs and compares some technical data. After the first production ofClassic 25 MF, some tests have been carried out in the laboratory and in the field. The outcomes of these tests are presented anddiscussed.