What size power station do I need?
Set a quantity for each appliance you want to run, plus how many hours a day. You get three numbers to compare against any power station's spec sheet.
| Appliance | Running W | Add'l starting W | Qty | Hours/day | Duty %* |
|---|---|---|---|---|---|
| Refrigerator/Freezer | 750 | 1600 | |||
| Deep Freezer | 500 | 500 | |||
| Mini Fridge | 600 | 200 | |||
| Microwave Oven - 1000W | 1000 | 0 | |||
| Coffee Maker | 1200 | 0 | |||
| Crock Pot | 250 | 0 | |||
| Toaster Oven | 1200 | 0 | |||
| Sump Pump - 1/3 HP | 800 | 2100 | |||
| Sump Pump - 1/2 HP | 1050 | 2200 | |||
| Water Well Pump - 1/3 HP | 1250 | 3750 | |||
| Furnace Fan Blower - 1/3 HP | 700 | 1400 | |||
| Furnace Fan Blower - 1/2 HP | 800 | 2350 | |||
| Space Heater | 1650 | 0 | |||
| Portable Heater | 625 | 1500 | |||
| Window AC - 10000 BTU | 1050 | 2100 | |||
| Box Fan - 20" | 150 | 0 | |||
| Humidifier - 13 Gallon | 175 | 0 | |||
| Cell Phone Charger | 25 | 0 | |||
| 60 Watt Light Bulb | 60 | 0 | |||
| Lamp | 100 | 0 | |||
| Laptop | 250 | 250 | |||
| LCD TV - 32" | 100 | 0 | |||
| Security System | 550 | 0 | |||
| AM/FM Radio | 100 | 0 | |||
| Washing Machine | 1000 | 3000 | |||
| Clothes Dryer - Gas | 700 | 1800 | |||
| 1/2 HP Garage Door Opener | 900 | 2400 | |||
| Inflator Pump | 200 | 0 |
How the math works
- Continuous W = sum of running watts × quantity (everything on at once).
- Surge W = continuous W + the single largest additional starting watts. The source chart assumes only one motor starts at a time.
- Battery Wh = Σ(running W × qty × hours × duty%) ÷ efficiency.
*Duty % is an estimate you can edit, not from the source chart; fridge/freezer defaults are derived from DOE/ENERGY STAR energy data (below). Fridges, freezers, pumps and furnace blowers cycle on and off. For a real figure, measure the appliance with a plug-in energy meter for 24 hours and set duty to 100% with the measured average watts. **85% is a common planning assumption for DC-to-AC inverter losses, not a measured figure. Check your model's manual.
Models that fit
Matches use only specs from manufacturer pages (see the comparison table). A model qualifies when its AC continuous watts, surge watts and battery Wh are all at least your numbers. Models with no published surge rating are only matched to loads without motor starts. Rated Wh is not all usable; the efficiency setting above covers inverter losses. Large units' top output may be 240V only. Check the source page.
Source for running/starting watts: LIFAN Power USA, Wattage Reference Chart (PDF) (checked 2026-10-27). Manufacturer estimates. 'Additional starting watts' = extra watts needed momentarily when the motor starts, on top of running watts.
Fridge, deep freezer and mini-fridge duty defaults come from measured annual energy: Refrigerator/Freezer: DOE: avg refrigerator-freezer 588 kWh/yr = 1,611 Wh/day; 1,611 / (750 W x 24 h) = 9%. https://www.energy.gov/cmei/buildings/articles/refrigerator-freezer-ec-rfi-faq · Deep Freezer: DOE: avg freezer 555 kWh/yr = 1,521 Wh/day; 1,521 / (500 W x 24 h) = 13%. same URL · Mini Fridge: Fridge.com analysis of ENERGY STAR certified list: compact refrigerator median 246 kWh/yr = 674 Wh/day; / (600 W x 24 h) = 5%. https://fridge.com/data/energy-index. The other cycling defaults (pumps, furnace blowers) are estimates.
Safety: never connect a power station or generator to house wiring without a transfer switch or inlet installed by a licensed electrician. Some manufacturers say their stations are not intended for life-sustaining medical equipment; ask your provider about medical devices.