This residential backup power project features a 3.5kVA inverter paired with four 12V, 200Ah batteries connected in series to form a 48V, 200Ah battery bank with approximately 9.6kWh of nominal energy storage. The system is designed to power essential household loads, including LED lighting, fans, televisions, a decoder, internet router, phone charging, and a suitable energy-efficient refrigerator. It provides dependable backup power during grid outages, with runtime depending on the connected loads and battery usage limits.