The performance and life cycle of Sealed Lead Acid (SLA) batteries for Advanced Metering Infrastructure (AMI) application is considered in this paper. Cyclic test and thermal accelerated aging test is performed to analyze the aging mechanism resulting in gradual loss of performance and finally to battery's end of service life. The objective of this study is to confirm design concepts, find the life characteristic and develop standard information on failure rates and mechanisms. Reliability assessment of the SLA is evaluated using different parametric distribution analysis models and best fit distribution is selected based on Anderson–Darling adjustment value. Shape parameter (β), scale parameter (α) and threshold parameter (λ) of the selected Weibull distribution is computed from experimental cycle life test data. Thermally accelerated aging test of SLA is performed and analyzed. Failure times are extrapolated to predict the lifetimes at the desired operational field temperature.