Adding battery packs to a solar generator allows users to store more energy, which provides continuous power availability. Lithium battery packs provide higher energy density, faster charging, longer lifespan, and deeper discharge capacity than lead-acid and NiMH batteries. We combine high energy density batteries, power conversion and control systems in an upgraded shipping container package. Our design incorporates safety protection. Adding Containerized Battery Energy Storage System (BESS) to solar, wind, EV charger, and other renewable energy applications can reduce energy costs, minimize carbon footprint, and increase energy efficiency.