Divide loads into Tier 1, Tier 2 and optional. Tier 1 might be lights, router, refrigerator and medical equipment. Tier 2 could add fans and selected sockets. Optional loads such as air conditioning or water heating can stay off during outages.
Size the first battery/inverter system for Tier 1, then check the incremental cost of Tier 2. This prevents a single heavy appliance from doubling the storage budget. It also makes the system easier to expand later.
Verify the installation after commissioning
Test an actual outage while the installer is present. Confirm essential circuits transfer correctly, the inverter does not overload during motor startup and monitoring shows expected battery state. Ask for shutdown and emergency instructions.
Keep a simple maintenance log with battery alarms, firmware updates and unusual capacity changes. A backup system is valuable only when it is ready during the outage; testing it periodically is part of ownership.