Vertical stackable LFP residential batteries cover 5kWh–30kWh with parallel expansion capability, widely used for household PV, power outage backup and peak-valley arbitrage. 51.2V low-voltage models prevail. A 5kWh battery matches 3–4kW inverter with 3kW continuous max load; 10kWh unit suits 5–6kW inverter for 5kW continuous load. Separate vertical batteries require independent inverters with flexible wiring and scalable capacity. All-in-one energy storage systems integrate battery, PCS and EMS, pre-wired at factory for quick installation yet limited expandability. Suitable for villas, urban apartments and off-grid cabins. Users can choose split or integrated systems based on load demand and future expansion plans.