Rules
Home Backup Power: What a Portable Power Station Can and Can't Run
Real appliance wattage, surge draw, and runtime math for sizing a portable power station, plus what it cannot run during a home power outage.
What to take away
- A portable power station is a battery and an inverter in a box. It runs what you would plug into a wall outlet, up to its continuous watt rating.
- Home backup power basics come down to three numberscontinuous watts, surge watts, and watt hours of capacity.
- Refrigerators, routers, laptops, fans, lights, and CPAP machines are realistic loads. Central air conditioning, electric furnaces, and electric water heaters are not.
- Runtime is watt hours divided by the load in watts, trimmed for inverter losses and DC conversion.
- Solar panels change how fast a station refills, not how big the tank is.
Running watts, surge watts, and watt hours
Every appliance carries two power numbers. Running watts is the draw once the device is on and steady. Surge watts, sometimes called starting watts, is the brief spike when a motor or compressor kicks in.
A refrigerator might run at 150 watts and spike past 1,000 watts for a second or two. An inverter that handles the running load but not the surge will shut down or trip its breaker.
Watt hours describe the tank. A 1,000 Wh station holds roughly as much usable energy as a small car battery, minus what the inverter burns as heat.
Watt hours are the fuel tank. Watts are the size of the pipe. A big tank behind a narrow pipe still empties slowly.
Portable power station wattage guide for common appliances
Ask what can a portable power station run, and the honest answer starts with the labels on your own appliances. The ranges below are typical starting points. A plug-in power meter gives exact numbers.
Wattage guide for common appliances
| Appliance | Running watts | Startup surge | Realistic on a mid-size station |
|---|---|---|---|
| LED lights, 10 bulbs | 60 to 100 | none | Yes, for days |
| Wi-Fi router and modem | 10 to 30 | none | Yes, for days |
| Laptop on USB-C charging | 45 to 100 | none | Yes |
| Full-size refrigerator | 100 to 250 | 800 to 1,200 | Yes, with care |
| Microwave oven | 1,000 to 1,500 | none | Yes, briefly |
| Coffee maker | 900 to 1,200 | none | Yes, briefly |
| Sump pump, 1/3 hp | 800 | 1,300 to 2,000 | Large stations only |
| Window air conditioner, 5,000 BTU | 450 to 600 | 1,000 to 1,500 | Large stations only |
| Well pump, 1/2 hp at 240 V | 1,000 | 2,000 to 3,000 | No, needs 240 V output |
| Central air conditioner, 3 ton | 3,000 to 4,000 | 10,000 or more | No |
| Electric water heater | 4,000 to 4,500 | none | No |
Power station runtime explained in four steps
Runtime explained in four steps
- List the running watts for every device you want to keep alive.
- Add them to get your total load in watts.
- Divide the station watt hours by that total.
- Subtract inverter losses, then adjust for duty cycle on compressors and pumps.
A refrigerator compressor does not run constantly. If it runs one third of the time, its average draw is one third of its running watts, which stretches runtime.
A 1,500 Wh station on a 100 W load should last about 15 hours on paper and closer to 13 in practice.
Example: a fridge, a router, and one overnight outage
Sizing a portable power station for a fridge is the most common version of this question. A modern 18 cubic foot refrigerator draws about 150 watts with the compressor running.
It cycles roughly one third of the time, so the average draw sits near 50 watts. Over 24 hours the fridge needs about 1,200 watt hours.
A router and modem add 15 watts, or 360 watt hours across a full day. A 2,000 Wh station covers both and leaves room for a phone and a lamp.
Keep the door shut and the coils clean to cut the total.
What a portable power station cannot run
Electric resistance heat sets the hard limit. Electric furnaces, water heaters, ranges, and clothes dryers pull 3,000 to 5,000 watts or more, often at 240 volts.
Most portable stations output 120 volts only. That rules out well pumps, electric dryers, and central air conditioning unless you buy a 240 V model.
Capacity fades with cycle count and heat, so an older or used station may hold less than its label claims.
Hardwiring a station into a house panel needs a transfer switch or an interlock kit. The National Electrical Code covers those installation rules, and a mistake can energize lines utility crews are working on.
Panels, 240 V output, and the buying decision
A station with folding panels and a charge controller makes it a solar generator, which lets you refill between outages instead of running once and stopping.
The two designs aim at the same job from different angles. Solar generator versus power station sets out what each one actually backs up in a US outage and what both cost.
If a storm is forecast to last days, plan the recharge path first: wall outlet, car 12 V socket, or panels.
