For this project a custom-built solution was developed on the basis of the Xtender Power AC10048. The system consists of a plug’play control cabinet with a total of 7kVA output, a 5kWp PV generator and a battery bank with 900Ah / 48V. The OPzS batteries are operated with liquid electrolyte. An electrolyte circulating pump was integrated into the control cabinet to prevent acid layering and to increase the efficiency.