Economical acquisition and use of batteries. Traditions and beliefs as a hinder

There are many deeply rooted beliefs in the use of batteries affecting the economical acquisition and use of them. These traditions and beliefs stem mostly from the recommendations of battery manufacturers. These recommendations are often based more on the business interests of battery manufacturers then on the interests of battery users. These traditions and beliefs have cause substantial extra costs for users during the last twenty years. The persistent belief that a 20% reduction of nominal capacity means the end of useful battery life and that the reduction will certainly take place during the design life of the battery as well as that only similar (i.e. age, capacity type, manufacturer and technology) battery strings can be connected in parallel, are such beliefs which have caused these extra costs. The costs are due to resulting battery sizing and disposal practices. This paper presents the studies carried out in Finland concerning the parallel connection of different battery strings. In addition, the practical constraints of paralleling and its effect on fault detection as well as on reliability performance are also discussed