The lead–acid battery is an old system, and its aging processes have been thoroughly investigated. Reviews regarding aging mechanisms, and expected service life, are found in the monographs by Bode and Berndt , and elsewhere , . The present paper is an up-date, summarizing the present understanding.
The reliability analysis of the lead acid battery is based on three stages. The first stage consists of constructing a causal tree that presents the various possible combinations of events that involves the batteries degradation during lead acid battery operation .
A battery is degraded by the superposition of the various degradation modes (sulfating, stratification, corrosion and non cohesion of active mass). Fig. 14, Fig. 15, Fig. 16 represent the experimental Nyquist diagram of 3 batteries (a new battery and 2 used batteries). Fig. 14. Diagram of Nyquist of the battery tested No. 1. Fully charged. Fig. 15.
A battery is degraded by the superposition of different degradation modes, thus the criterion of degradation is reached if the sum α1 + α2 + α3 + α4 equals 100%. The sum α1 + α2 + α3 + α4 indicates the aging of battery, it is considered degraded if the sum exceeds 100%. 5. Conclusion
On the other hand, at very high acid concentrations, service life also decreases, in particular due to higher rates of self-discharge, due to gas evolution, and increased danger of sulfation of the active material. 1. Introduction The lead–acid battery is an old system, and its aging processes have been thoroughly investigated.
Hariprakash et al. 14 investigated the correlation between increasing internal resistance and lead-acid battery degradation, and observed, via a curve fit of experimental data, a linear relationship between log (SOC) and ohmic resistance.