Lead –acid batteries are the most common type of secondary cells used in automotive industry. This diploma thesis deals with the influence of temperature on their lifetime. In the preamble of this work is shortly described their history, division, construction and processes during battery operation. There are noted unfavorable phenomena which have an impact on increasing the temperature inside the battery. The first experimental part is devoted to evaluation the effects of addition on the temperature rise during charging. The second part is focused on conditions simulation in hot areas at the temperature above 30 °C and effects of this temperature on the function of lead – acid batteries.