Stationary battery storage systems for home use mostly consist of lithium-ion cells, a battery management system (BMS), and an integrated or external inverter. The BMS monitors cell voltages, temperatures, and charging currents to protect against deep discharge and overcharging. Storage capacities for single-family homes typically range from 5 to 20 kWh. A distinction is made between AC-coupled and DC-coupled systems: in AC coupling, the storage is connected via its own inverter; in DC coupling, it is integrated directly into the PV DC circuit. Modern systems are embedded in energy management systems and enable peak load shaving, backup power supply, and participation in balancing energy markets via cloud-based control.