Home backup
For homeowners separating essential circuits from whole-home demand and planning a safe return to grid supply.
Sources and methodology
Source-based desk research and explicit calculations; no hands-on testing claimed. Missing values remain unknown. Installation compatibility needs a separate assessment.
Typical loads
Inventory refrigeration, communications, heating controls, circulation pumps and selected sockets. Measure simultaneous load and motor starts. An electric boiler can dominate the energy budget even when used briefly.
System architecture
Battery → protected DC bus → inverter/charger → approved transfer arrangement → essential circuits. Earthing, neutral switching, residual-current protection and grid separation must be designed together for the chosen equipment.
Illustrative sizing
Illustrative envelope: 500–2000 W of essential demand for 4–8 hours. A 1 kW average load for 4 hours requires 4 kWh AC, or roughly 5.43 kWh stored with 80% usable depth and 92% efficiency. Starting power is an independent constraint.
Solar and generator
Existing grid-tied PV may disconnect during outages. Confirm backup-mode solar compatibility rather than assuming roof panels keep producing for the house. Generator charging is possible only within charger and transfer specifications.
Recommended equipment categories
Backup power
Keep essential loads operating with a defined autonomy and transfer requirement.
Batteries
Compare usable storage, DC voltage and discharge limits before choosing capacity.
Inverters
Match continuous AC demand, starting surge and battery voltage.
Electrical components
Complete the power path with correctly rated cables, isolation and protection.
Guides for this solution
Frequently asked questions
Is this a final installation recommendation?
No. Verify model manuals, actual loads, protection and site conditions with a qualified professional. Calculations and equipment classes are preliminary planning aids.
Where do I buy and who sets the price?
Purchase is with the external supplier, who controls price, delivery, inventory and returns. Confirm delivery to Romania before ordering. Commercial disclosure →