Do not assume a battery provides backup. Ask for the exact equipment, circuits and operating limits included.
Name what must stay on
List the appliances you need during an interruption, such as refrigeration, communication or lighting. Their combined running and starting loads matter. Treat critical medical equipment as a separate requirement needing appropriate professional advice and a dependable backup plan.
Understand the installation
Backup operation may require compatible equipment, switching arrangements and dedicated circuits. Ask whether the system supports the whole home or only selected loads, whether switching is automatic and whether solar can recharge it while disconnected from the grid.
Balance reserve and everyday use
Energy kept in reserve for an outage cannot also be counted as fully available for routine savings. Ask how reserve settings work and how long your chosen loads might run. Runtime estimates should use usable capacity and realistic appliance consumption.