Overcharge is an effect caused by a condition that maintains high current passing for a long period of time in the battery. These periods can be continuous or interrupted. Chemical reactions, as every physical phenomenon, have a maximum speed to occur. When we increase current charge of a battery, we are increasing the speed of charge reaction. There is a point in which energy supplied to the battery exceeds the capacity to be absorbed by the materials that compose it. The exceeding energy is then transformed into heat. Automotive batteries present high thermic resistance, that is, heat generated in its interior, is difficult to dissipate, causing increase on the temperature. High temperature leads to burning of active chemical elements (which are part of charge and discharge), requesting mechanically its components, therefore, causing buckling on the plates and generating early death of battery.