Medium and large apartments can install larger solar panels on balconies, paired with 5–8kWh large-capacity wall-mounted storage. It stores surplus daytime PV electricity to run high-power appliances such as air conditioners and washing machines, greatly reducing grid power reliance. The wall-mounted design keeps floors unobstructed without disrupting balcony layout. With high IP dustproof and waterproof rating, it withstands sunlight and light rain for open or semi-open balconies. It automatically switches between PV charging and grid supplementary power, balances charge and discharge intelligently, and stores power flexibly under peak-valley tariffs to slash long-term electricity costs while delivering comfort and energy-saving benefits.