1. Lubomir Soos, Slovak University of Technology in Bratislava, Faculty of Mechanical Engineering, Bratislava, Slovakia
2. Pavel Kovač, University of Novi Sad, Faculty of tehnical science, Serbia
3. Dušan Ješić, International technology Management Academy, Trg D.Obradovića 7, 21000 Novi Sad, 4. Borislav Savković, Faculty of Technical Sciences, University of Novi Sad, Serbia
Acid lead batteries, also known as starter accumulators, are used as an energy supply for starter motors. Their lifetime is limited by incorrect use and lack of maintenance.
The accumulator consists of cells connected with each other to form a battery. The cells contain electrodes, separators and an electrolyte. On the positively charged electrodes (e.g. plates) the activator is PbO2. On the negatively charged electrodes the activator is mycotic lead. The separators impede the mechanical contact between the electrodes. The electrolyte dilutes the concentrated sulphuric acid, H2SO4 (the so-called accumulator acid) to a concentration of 1,285 kg/m3. Content of materials is next: Pb metals 28%, accumulator acid 25%, PbSO4 20%, PbOx 15%, ebonite separators, polypropylene 12%
The measure of the accumulator “recycling rate” is the percentage of accumulators that have been recycled out of all discarded accumulators in a particular year. In developed western countries the official rate is between 75 % and 95 %, and is often supported by non-market means, such as “recycling fees”. This method means that the buyer pays part of the total costs of the future ecological recycling of the product. The first country to introduce such a recycling fee was Sweden. In the early years of the fee, the rate of return of accumulators was almost 100 %. When the authorities realized that the return rate was not falling, they discovered that some of the “merchants” were importing used accumulators from neighbouring countries in order to claim the recycling fee.
The growing number of used lead accumulators is becoming one of the most pressing environmental problems in Slovakia as well as elsewhere. Used accumulators are considered as a dangerous waste from the point of view of waste laws, both in Slovakia and abroad, but at the same time they represent an interesting raw material source. There are several authorized companies which deal with the recovery and destruction of used batteries, and in Slovakia used accumulators can be left in waste collection areas.