The present manual does not provide complex theoretical calculations, formulas and graphs describing the entire variety of electrochemical and physical processes occurring in the battery. Only acid starter batteries are considered. A minimum amount of concepts and information is given, sufficient to understand the main processes, allowing the motorist to independently organize rational care for the battery without much effort and time and extend its uptime. The manual is intended for motorists, who are mostly not specialists in the field of chemical current sources, but it is assumed that the reader has an idea of the device of a modern battery.