This first edition of Dr. Berndt's book was published in 1993 and was immediately given good reception from both industrial battery technologists and academics. It was particularly welcomed because it started from basic principles of electrochemistry and physics, and demonstrated their effects on the performance and characteristics of batteries, following their implications through to actual applications of batteries in the field. Maintenance-free batteries are a rapidly changing subject and, since 1993, there have been advances and developments, particularly in the new valve-regulated lead-acid and nickel/metal hydride types. It was therefore decided that it was time for a second edition of the book. In this edition, there is a wealth of new information. Dr. Berndt has also taken the opportunity of reorganizing the format to some extent, to give as logical an approach as possible to the subject, and including more detailed explanations for greater clarity.