The xStorage battery energy storage system (BESS) optimizes energy usage and supports energy storage, electric vehicle integration and grid modernization. In the event of a utility power interruption, the xStorage BESS provides an environmentally friendly backup, reducing reliance on traditional generators with its 250 to 1000 kWh of usable stored energy. Additionally, it enables efficient solar self-consumption by storing excess energy from on-site sources like solar panels, and supports demand response by using stored energy to manage peak demands and avoid utility fees. The xStorage system includes a control cabinet with auxiliary transformer, power conversion system (PCS)/inverter and up to three battery cabinets, each housing six or eight battery modules, while predictive 24×7 monitoring and management proactively identifies risks and reduces downtime.