Start with Daily Consumption
A small home with essential backup needs may only require 5kWh, while a larger home with air conditioning, pumps, or longer outage coverage often needs 10kWh to 20kWh. The best starting point is the customer’s average daily electricity use.
Match Battery Size with Solar Output
Battery capacity should be matched with the solar array and inverter. Oversizing the battery without enough solar generation can slow charging, while undersizing may waste solar energy during the day.
Plan for Expansion
For importers and installers, modular systems are easier to sell because customers can begin with a practical capacity and add more batteries later as energy demand grows.