Split vertical batteries and all-in-one systems represent two mainstream residential storage solutions. Split vertical batteries are stacked separately with separately selected inverters. A 15kWh vertical battery matches 6–8kW inverter for 6kW continuous load. It supports battery stacking and independent inverter replacement, ideal for users planning future expansion. All-in-one ESS integrates battery and inverter inside one cabinet for simple wiring and fast commissioning, preferred by users seeking easy installation. Its drawbacks include high expansion cost; inverter faults often require whole-unit maintenance. Both options support PV self-consumption, emergency backup and off-grid housing. Split vertical systems are recommended for budget-conscious users with future expansion needs.