The aim of this paper is the quality control of the manufactured lead acid battery by using the causal and fault tree analysis. The causal tree allows the description of the correlations between the battery degradation modes and their causes during the manufacturing process. The causes of the degradation are the low quality of lead oxide, low grid oxidation, bad adjustment of temperature and density, wrong dosage of additives, irregular dosage of lead calcium or lead antimony, and existence of impurities. These causes facilitate the appearance of the degradation modes during the battery use such as the stratification of electrolyte, poor cohesion of active mass, hard sulfating, and corrosion of electrodes. The consequences of the several causes during the manufacturing process on the parameters of the electrical equivalent circuit of the battery are discussed to elaborate the fault tree and analyze the new manufactured lead acid battery quality. In fact, a diagnostic method based on the analysis of the electrical equivalent circuit parameters' variation is developed. This diagnostic method allows the determination of the rated capacity loss and the degradation depth of new manufactured lead acid battery. Therefore, this study allows identifying the causes leading to manufacturing defects and their impact on the available rated capacity of the battery to judge its quality.