EVERYDAY UTILITIES · BACKUP ELECTRICITY
Home Outage Backup Planner
Build a realistic backup-power scenario for your router, laptop, lights or refrigerator. Estimate battery energy requirements and flag possible inverter output limits.
Plans are saved only on this browser. No login or uploaded measurements.
Guidance and limits
Why do I need watt-hours, not just watts?
Watts measure instantaneous power while watt-hours measure energy over time. A 40 W load run for five hours uses approximately 200 Wh before conversion losses.
Do you calculate startup surge?
We show a conservative screen assuming all listed active devices are running and the largest single device starts. Multiple motors starting together can exceed this value. Check your exact station surge rating.
Is your fridge runtime guaranteed?
No. A refrigerator cycles unpredictably and may have a substantial startup surge. Use actual power-meter readings, temperature, door-opening patterns and product documentation.
Can I connect a portable station to home wiring?
Do not backfeed a wall outlet or building circuits. Household wiring and transfer equipment require qualified installation and compliance with local safety rules.
What happens to my input data?
All inputs remain in your own browser local storage; JSON export is downloaded locally. No profile or account is created.
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