List only essential devices. Multiply each wattage by its operating hours, then add a margin for conversion losses.
Make it practical
Check continuous and startup output separately from energy capacity. Heating appliances use large amounts of energy. Ask a qualified professional about safe connection and medically critical backup needs.
Inventory loads before comparing stations
- Record device wattage from a reliable specification or measurement; note whether the load is continuous or intermittent.
- Choose realistic runtime for each device. Refrigerators cycle, while heaters may draw substantial power for long periods.
- Calculate energy with the estimator, then separately verify simultaneous watts, startup surge, plugs, voltage, and charging requirements.
Plan the second day
A battery eventually empties. Consider how and where you could recharge it and whether solar exposure, weather, and panel compatibility support your assumptions. Keep alternatives such as relocating to a powered safe location. A medically critical load needs a provider-approved continuity plan; an online runtime estimate alone is insufficient. Only qualified professionals should design a connection to household wiring.
Sources & reading
Source check: November 1, 2026. Educational synthesis; no government affiliation. During an emergency, follow current local instructions.