How Long Will It Run

Generator or power station for a power outage?

Both keep the lights on, and they solve different problems. A generator makes electricity for as long as you keep feeding it fuel. A power station is a battery: it hands back what you put in, silently and indoors, and then it needs recharging. Which suits you comes down to how long your outages last, what you need to run, and where the machine can sit.

Size a station for your outage The cheap outage kit

The short answer

How long a battery lasts on outage loads

From full, one appliance at a time, on US 120 V appliances. A generator has no such limit: it runs until the tank is empty and starts again when you refill it.

ApplianceAnker SOLIX C1000 (1,056 Wh)Bluetti AC180 (1,152 Wh)Jackery Explorer 2000 Plus (2,042 Wh)EcoFlow DELTA Pro 3 (4,096 Wh)
Fridge-freezer (full size)12 h 5 min12 h 59 min22 h 19 min41 h 4 min
Gas furnace (blower and controls)2 h 28 min2 h 41 min4 h 44 min9 h 18 min
Window air conditioner, 5,000 BTU2 h 8 min2 h 19 min4 h 5 min8 h 3 min
Sump pump3 h 4 min3 h 19 min5 h 50 min11 h 27 min
Well pump (1/2 hp)Cannot start itCannot start it6 h 56 min13 h 32 min

“Cannot start it” means the appliance's start-up surge is more than the station's inverter can deliver, even though the battery has the energy. Motors are the hard part: see why the inverter trips and the furnace guide.

What a generator gives you

Take a small inverter generator, the Honda EU2200i. Honda's specification gives it 1,800 W rated and 2,200 W maximum output, a 0.95 gallon tank, and a run time per tankful of 3.2 hours at rated load and 8.1 hours at a quarter load. It weighs 47.4 lb and Honda lists it at $1,199.

Those figures work out to about 6.1 kWh per gallon worked hard and 3.8 kWh per gallon at a quarter load. At $4.48 a gallon (the EIA US average retail price for regular gasoline, week of 21 September 2026), that is roughly $0.74 to $1.17 per kWh in fuel alone. Generators are least efficient lightly loaded, which is exactly how an overnight fridge and a few lights load them.

A small generator has a surge limit too. The well pump (1/2 hp) modelled here needs 3,000 W to start, more than the Honda EU2200i's 2,200 W maximum, so jobs like that need a bigger conventional generator, usually wired in through a transfer switch.

What a power station gives you

Recharging from the wall costs 18.34¢ per kWh at the EIA US residential average, June 2026, plus about 10% lost in charging. A full charge of the Anker SOLIX C1000 costs about $0.22, and of the EcoFlow DELTA Pro 3 about $0.83. That matters less than it looks, because in an outage the question is not the price of a kWh but where the next one comes from: a working outlet elsewhere, a car, solar panels, or a generator.

The rest of the case for a station is practical. It can sit in the bedroom or on the kitchen counter beside the fridge. It makes only fan noise, needs no oil changes and no fuel storage, and is ready the moment the grid drops if you keep it charged. Stations with a UPS or pass-through mode can sit in line with a fridge or router and take over automatically.

Side by side

Inverter generatorPower station
Where it runsOutdoors, 20 ft or more from the houseIndoors, next to what it powers
How longAs long as you have fuelUntil the battery is empty
Energy costAbout $0.74–$1.17 per kWh in fuelAbout 20¢ per kWh from the wall
Noise48–57 dB(A) for the Honda EU2200iCooling fan only
UpkeepOil changes and fresh fuelKeep it charged
Big motorsSurge limited by its size, like a stationOnly the larger stations, and not for long

Connecting either one to the house

Extension cords to the appliances are the simple, safe way. Anything that feeds house circuits, such as a furnace or well pump, needs a transfer switch or an interlock fitted by a licensed electrician. Never back-feed the house through a wall outlet: it can kill a line worker restoring power.

The power outage essentials list covers the cheap kit that does most of the work in a short outage, and the station catalogue has the runtime for every appliance on every model.