List the circuits and appliances you need during an outage, then check each device's running and starting demand, voltage and expected hours of use. Compare those loads with the backup source's continuous output, surge rating, usable energy and required transfer equipment. For technology tradeoffs, see our battery, generator and power-station comparison.
Backup equipment is easier to compare after you decide what must stay on. A refrigerator, a few lights and communications equipment create a different load plan from a well pump, electric range or central HVAC system.
Make a load sheet
| Record | Where to find it |
|---|---|
| Voltage and amperage | Appliance nameplate or manual |
| Running watts | Manual, label or manufacturer support page |
| Starting demand | Manufacturer’s motor or compressor documentation |
| Hours needed | Your expected outage routine |
| Circuit location | Panel schedule, checked by a qualified electrician when unclear |
Separate loads that can run together from those you can cycle. Compare the combined demand with the backup source’s continuous output and surge rating, and compare the hours needed with usable energy and refueling or recharge options.
Choose the connection method
Portable power stations can serve selected plug-in devices within their output limits. Generators can support longer operation when fuel is available, but outdoor placement and transfer equipment matter. A home battery can support selected circuits through listed equipment and a permitted electrical installation. Never connect a generator through a wall receptacle; use an approved transfer switch or interlock installed to local requirements.
For the source-type tradeoffs, read our home battery vs generator vs power station comparison. For EV charging loads, see Level 2 charger requirements.
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Common questions
How do I estimate how much backup power I need?
Make a list of devices, their input ratings and hours of use. Add simultaneous loads and any motor starting demand, then compare with the backup unit's continuous and surge ratings.
Can a portable power station run a 240V appliance?
Only if that specific model provides the required voltage and output. Check the product manual and connector details.
Can I connect a generator to a wall outlet?
No. Use only an approved transfer arrangement installed according to the equipment instructions and local electrical code.