Power Station vs Generator: Real Cost per kWh and Runtime

The short answer

For a house that loses power a few times a year, a battery power station in the 1 to 4 kilowatt-hour (kWh) class is the better buy: it runs indoors, makes no carbon monoxide, needs no fuel, and costs a third to a fifth as much per kilowatt-hour to feed. A gasoline generator wins the moment an outage runs past two or three days, or the load includes a well pump, an electric water heater or anything else that needs 240 volts and thousands of watts for hours. The numbers below come from the makers’ own spec sheets, not from either side’s marketing, and the prices are as of September 8, 2026.

Those three are the reference products for this page because each publishes the numbers the comparison needs. The Honda is a widely sold quiet inverter generator with a complete spec sheet; the DELTA 3 is a typical 1 kWh battery; the F3800 is the class of battery that can run a whole circuit panel. Swap in your own models and the division below still works. One result to hold onto: the battery’s electricity is cheap, but a battery used ten times a year costs about $8 per kilowatt-hour once you count the box itself, which is the number that decides who should buy which.

What does each one cost to run, per kilowatt-hour?

Start with the generator, because its spec sheet tells you everything. Honda lists the EU2200i at “1800W rated (15A),” with a “Fuel Tank Capacity .95 gal” and a “Run Time per Tankful 3.2hr @ rated load 8.1 hrs @ 1/4 load.” At rated load, 1.8 kW for 3.2 hours is 5.76 kWh from 0.95 gallons, or 0.165 gallons per kWh. At a quarter load, taken here as a quarter of the 1,800 W rated output since Honda’s sheet does not say which figure it means, 0.45 kW for 8.1 hours is 3.65 kWh from the same tank, or 0.26 gallons per kWh: the engine gets less efficient the lighter the load, which is exactly how a generator spends most of an outage. The Energy Information Administration (EIA) put regular gasoline at $4.071 a gallon for the week ending August 31, 2026. Fuel alone, then, costs about $0.67 per kWh at full load and about $1.06 per kWh at quarter load. A 24-hour day at the quarter-load rate burns about 2.8 gallons, or roughly $11.50, and needs a fresh tank about every eight hours.

Now the battery, which has two costs where the generator has one. The first is the electricity you put in. The EIA’s June 2026 residential average was 18.34 cents per kWh. Not all of it comes back out: Jackery’s own runtime formula is “Working time = Explorer’s Watt-Hours * 0.85 / operating power of your device,” which is the allowance this site’s sizing guide applies to every station for what the inverter and battery lose. Divide 18.34 by 0.85 and grid electricity costs about 21.6 cents per delivered kWh, a third of the generator’s full-load case and a fifth of its quarter-load case.

The second cost is the battery itself, and this is the number nobody on either side puts in a table. EcoFlow rates the DELTA 3 at “4000 cycles to 80% capacity” and lists it at $699, on sale for $629. If you really did use all 4,000 cycles, 4,000 times 1.024 kWh is about 4,100 kWh stored over the battery’s life, and $699 divided by that is 17 cents per stored kWh, or about 20 cents per delivered kWh after the 0.85 factor. Add the electricity and a heavily used battery lands near 42 cents per kWh, still well under the generator’s fuel alone. But almost nobody cycles a backup battery 4,000 times. A battery that sees ten outages a year for ten years, 100 full cycles, spreads that $699 over about 87 delivered kWh, which is $8 per kWh before the electricity. The generator’s cost per kWh is the same on its first outage and its hundredth. The battery’s depends entirely on how much you use it, which is why the right answer differs for a house that loses power twice a year and a cabin that runs on it every weekend.

Honda does not publish a service-life figure in hours for the EU2200i, so the generator’s hardware cost per kWh cannot be computed the same way; its $1,199 price is real but its denominator is unknown.

How long will each one run a fridge, the internet and a CPAP?

Take a realistic outage load: a full-size refrigerator, a Starlink Mini for internet, one laptop charge a day, and a CPAP (continuous positive airway pressure) machine overnight. Every draw here is from a maker’s spec sheet or a federal label; the sizing guide has more devices.

Call it 2,400 Wh delivered per day, which after the 0.85 factor is about 2,800 Wh of rated battery per day and 8,500 Wh for a three-day storm. The DELTA 3’s 1,024 Wh covers about nine hours of that day. The F3800’s 3,840 Wh, about 3,260 Wh usable, covers a day and a third, or nearly three days if the fridge is the only load. Three full days on battery alone means roughly 8.5 kWh of capacity, more than two F3800-class units, or one plus a way to refill it: solar panels, a car’s alternator, or a generator.

The generator’s version of the same three days is a fuel-logistics problem rather than a capacity problem. That 2,400 Wh day averages about 100 W, far below even the quarter-load point on Honda’s sheet, and Honda publishes no consumption figure lower than the quarter-load 8.1 hours per tank, so the best sourced estimate is about 2.8 gallons a day, roughly 8.5 gallons and $34 in fuel for the three days, with the tank refilled every eight hours, at night, in the weather, with the engine cooled first. That is the trade in one sentence: the battery runs out, the generator runs on, and the generator makes you work for it.

One caveat on starting loads. Honda’s own sizing chart lists a refrigerator at 200 running watts but 1,600 starting watts, and a furnace fan at 600 running and 1,600 starting. An 1,800 W generator and an 1,800 W battery both handle one of those at a time; the 600 W-rated RIVER Max class does not, whatever its watt-hours say.

How loud is a generator compared with a power station?

Honda’s spec sheet gives the EU2200i as “57 dB(A) @ rated load 48 dB(A) @ 1/4 load,” and its marketing calls that “less noise than a normal conversation.” That is a quiet generator by design, and the spec sheet is the line to compare on any other model. The DELTA 3’s spec line reads “Noise 600W<30db;1200W<40db,” a fan that EcoFlow describes as “Completely imperceptible under 600W. Both figures are the makers’ own measurements under their own conditions, so treat the gap as directional: a good inverter generator is a conversation in the yard all night, and a battery is a fridge hum indoors. For neighbors, sleep and not advertising that you have power, that gap may matter more than the cost figures.

Can you run a power station indoors? The carbon monoxide numbers

Yes, and that single fact is the strongest argument for the battery. A generator’s exhaust is the reason the Consumer Product Safety Commission (CPSC) has been trying to regulate them for two decades. In its April 2023 supplemental proposed rule, the commission wrote: “for the three most recent years for which complete data are available (2017 through 2019), generator-related CO deaths have averaged 85 per year,” and that its field staff had investigated “nearly all 1,332 deaths” in its records over an 18-year period. Portable generators, it added, account “for over 90 percent of the 900 reported fatalities associated with all EDTs during the period 2011 to 2021,” EDTs being engine-driven tools.

Honda’s manual does not soften it: “Breathing carbon monoxide can KILL YOU IN MINUTES,” and “Never operate a generator inside a house, garage, basement, crawl space, any type of vehicle, trailer, or boat, or any enclosed or partly enclosed space.” The Electrical Safety Foundation International’s rule is a distance: “Always keep generators at least 20 feet away from your home.” Twenty feet from the house, in the rain, with a cord run through a cracked window, is the real operating condition of a generator in a storm, and it is worth picturing before you buy one.

Modern Honda units carry a shutoff: the EU2200i’s CO-MINDER “continuously monitors carbon monoxide (CO) levels” and “automatically shuts down the generator before detected CO levels near the generator become dangerously high.” That is a real safety improvement and it is not a license to bring the machine inside; the manual’s prohibition stands regardless.

What maintenance does each one need?

A generator is a small engine, and Honda’s manual treats it as one. Its quick-reference page says “Before each use Check engine oil level. Check air filters. First 20 hours Change engine oil,” with a “Maximum oil capacity: 14 oz (0.44 L),” and “The spark arrester must be serviced every 100 hours.” The part most owners get wrong is the fuel: “Fuel deterioration and oxidation can occur in as little as 30 days and may cause damage to the carburetor and/or fuel system.” Honda’s storage table says that after “1 to 2 months” in storage you should “Fill with fresh gasoline and add gasoline stabilizer,” and after “1 year or more” you should “Drain the fuel tank and carburetor.” A generator that sits in the garage from one storm season to the next with last year’s gas in it is the one that will not start when the lights go out.

A battery’s maintenance is a calendar reminder. EcoFlow’s own guidance: “For long-term storage, aim to keep the battery at around 50%,” “check the charge every 3–6 months and recharge to 50% as needed,” and store it “between 32°F and 77°F (0°C to 25°C).” The wear item is the battery itself, and the current lithium iron phosphate (LFP) chemistry has moved that horizon out: EcoFlow’s “4000 cycles to 80% capacity” and Anker’s “LFP, 3,000+ cycles” for the F3800 are both maker claims, but they are claims measured in a decade of use. The brands guide explains why LFP is the one spec to insist on.

When the generator still wins

Three cases, and they are common enough to say plainly.

Long outages. After the ice storm, the hurricane, or the wildfire evacuation that lasts a week, a battery is a bucket and a generator is a tap. The three-day table above needs 8.5 kWh of battery; a week needs 20. Gasoline resupply is a trip to a station; battery resupply without sun is another battery. The practical hybrid, which the makers now sell as a bundle, is a generator that recharges the battery: EcoFlow lists a “Smart Generator 3000 (Dual Fuel)” as one of the DELTA 3’s charging options, so the engine runs a few hours a day at its efficient load and the battery carries the quiet hours.

Big 240-volt loads. A well pump, a central air-conditioner or an electric water heater needs a 240 V circuit and thousands of watts for hours. The F3800 class can do it (“6,000W, 120V&240V Dual Voltage”) but at $2,000 per 3.84 kWh it is an expensive way to pump water; a 240 V generator does it for the price of fuel.

Heat. The sizing guide works through why a 1,500 W space heater empties a 2 kWh battery in about an hour. In a winter outage the battery runs the furnace fan, the fridge, the phones and the internet; the heat comes from combustion or blankets, whichever machine you own.

Can a portable power station charge an EV?

Technically yes, and the numbers say not to plan on it. The EPA rates a 2026 Tesla Model 3 Standard RWD at 24.3 kWh per 100 miles and a 2026 Hyundai Ioniq 5 RWD at 30.0. One delivered kilowatt-hour is therefore about four miles in the Tesla and about three in the Hyundai. A 576 Wh RIVER Max, about 490 Wh usable, adds two miles in the Tesla and about a mile and a half in the Hyundai; the DELTA 3 adds three to four; the F3800’s 3,260 usable Wh adds ten to thirteen. Anker markets exactly that use, “Charge Your EV Conveniently” through the F3800’s NEMA 14-50 port, and thirteen miles is enough to reach a charger, which is the whole point.

There is a draw problem too. The Department of Energy’s charging-levels page rates Level 1, the cord that came with the car, at “Approximately 5 miles of range per 1 hour of charging” on an assumed 1.9 kW. That is above the RIVER Max’s “3 x 600W AC OUTLETS” rating and above the DELTA 3’s 1,800 W continuous output as well; EcoFlow’s X-Boost mode claims “2200W (surge 3600W),” and at a 1.9 kW draw a full DELTA 3’s 870 usable watt-hours are gone in about half an hour.

The comparison runs the other way more usefully. An EV is a large battery on wheels, and two of the cars on sale export power from it. Hyundai’s US launch release says the Ioniq 5’s vehicle-to-load function delivers “1.9 kW peak power using a standard 120-volt outlet,” and “This function can even be used to charge a stranded EV,” “ideal for powering necessities during a power outage.” Tesla’s shop page for the Universal Wall Connector says you can “Power your home during an outage for up to three days using Tesla Powershare technology. Currently available for Cybertruck only.” If you already own one of those cars, the power station in your garage may be the car.

Frequently asked questions

How long will a power station run a refrigerator?

About 18 hours per 1,000 Wh of rated battery for a full-size fridge that uses 422 kWh a year, per its EnergyGuide label; a 3,840 Wh unit runs it nearly three days.

Which is better for a CPAP?

The battery, because it runs beside the bed. A ResMed AirSense 11 at its typical 56.1 W uses about 450 Wh in eight hours, which a 1 kWh unit covers with margin.

Can I charge the power station from the generator?

Yes, and it is the best use of both. The DELTA 3 lists “Smart Generator Charging (1.8kW)” among its inputs; any generator with a 120 V outlet can do the same job through the station’s AC charger.

Which one to buy

If your outages are measured in hours and your loads are a fridge, the internet, phones and a medical device, buy a 1 to 2 kWh LFP power station and keep it at half charge on a shelf; it will cost about 22 cents per delivered kWh in electricity, after inverter losses, nothing to store, and the price of the box spread over however many outages it ever sees. If your outages are measured in days, or you have a well, buy the generator, put it 20 feet from the house, and change the gas every couple of months. If you can afford both, the generator refills the battery for a few hours a day and the battery keeps the house quiet at night, which is how the makers themselves now package it. The one thing not to do is buy the generator for the fridge-and-phones outage: at a quarter load it already burns a dollar of gas per kilowatt-hour, a hundred-watt load is below any point Honda publishes a figure for, and it has to sit outside in the storm to do it.

Sources (20)

• powerequipment.honda.com Honda Power Equipment: EU2200i product page
• cdn.powerequipment.honda.com Honda: EU2200i Owner's Manual (PDF)
• powerequipment.honda.com Honda Power Equipment: What Size Generator Do I Need?
• govinfo.gov Federal Register: Safety Standard for Portable Generators (CPSC supplemental proposed rule, April 20, 2023)
• esfi.org Generator Safety
• eia.gov Weekly Retail Gasoline and Diesel Prices
• eia.gov EIA Electric Power Monthly, Table 5.6.A
• us.ecoflow.com EcoFlow: DELTA 3 product page
• us.ecoflow.com EcoFlow: RIVER Max legacy product page
• ankersolix.com F3800 product page
• ca.jackery.com Jackery: FAQ (runtime formula)
• ecoflow.com EcoFlow blog: How to Make Your Portable Power Station Last for Years
• products-salsify.geappliances.com GE Appliances: GTS19K refrigerator EnergyGuide label (FTC)
• starlink.com Mini Specification Sheet (PDF)
• document.resmed.com ResMed: AirSense 11 user guide, technical specifications (PDF)
• apple.com MacBook Air technical specifications
• fueleconomy.gov EPA fueleconomy.gov: vehicles dataset (model year 2026 entries)
• afdc.energy.gov DOE Alternative Fuels Data Center: Electric Vehicle Charging Stations
• prnewswire.com Hyundai via PR Newswire: IONIQ 5 Electric CUV Disrupts EV Market with Ultra-Fast Charging and Vehicle-to-Load Power Capability (May 24, 2021)
• shop.tesla.com Tesla Shop: Universal Wall Connector