Plan the loads before choosing the battery. This household power-outage planner adds up the devices you want to run, estimates the energy they need each day, compares your full list with essential loads, and creates a printable worksheet.
Your energy budget
Use the calculator to estimate your repeating daily energy budget.
Household worksheet
Household contact: ____________________
Alternative location: ____________________
Battery check or recharge arrangement: ______________________________
Review date: ____________________
Start with your own measurements
Replace every example with information for your actual equipment. Watts describe power at a moment; watt-hours describe energy used over time. A 10-watt light enabled for six hours at full power uses 60 watt-hours. Two such lights use 120 watt-hours. Device energy in this planner is watts multiplied by daily enabled hours, duty cycle and quantity.
If you enter measured average watts, use 100% duty cycle. If you enter watts while a cycling device is actively running, enter the measured fraction of its enabled period that it runs. Discounting an average again understates the energy needed.
Separate battery capacity from delivered energy
The planner divides device energy by your conversion-efficiency assumption and adds your battery-side idle draw for 24 hours each day. It then compares that demand with the rated battery capacity, the capacity fraction you expect to have available, and the reserve you choose to leave unused. The example assumptions are not measured product specifications.
The result is equivalent days of your repeating schedule. It does not mean every appliance runs continuously for that period. It includes no recharge from solar, mains or a generator. Check your exact equipment documentation and practice with the intended setup before relying on the estimate.
Power limits still need a separate check
A large watt-hour rating does not establish that a station can start a compressor or support your simultaneous loads. Check continuous output, starting surge, ports, compatible adapters and the manufacturer’s operating limits separately. Medical equipment requires its own device-provider outage plan; this general energy worksheet does not establish suitability.
Fuel-powered generators must be used outdoors, at least 20 feet from homes and buildings, with exhaust directed away from windows, doors and vents. Follow the manual and maintain working carbon-monoxide alarms. Never feed house wiring through an ordinary outlet.
Connect the rest of your household plan
- Build a layered outage power plan.
- Work out your emergency water storage.
- Plan multiple ways to receive information and communicate.
Sources and assumptions
The US Department of Energy’s Energy Savers guide explains watt-hours. Generator precautions follow the CPSC’s 2026 hurricane-season guidance and its portable generator safety alert. Reserve, available capacity, efficiency and idle draw are user-selected modeling assumptions. Research and software prototype prepared September 14, 2026. No physical equipment testing was performed.