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, a job for a larger generator than the 120-volt Honda in this table. The numbers below come from the makers’ own product pages and manuals and from federal data, and a maker’s marketing line is labelled as one. Prices are as of October 11, 2026, and both battery prices are limited-time sale prices.

Those three are the reference products for this page because each publishes most of the numbers the comparison needs, and the gaps are named where they matter. The Honda is a quiet inverter generator whose spec sheet gives a tank size and two runtimes, enough to compute a fuel cost; its page also marks it “Not for sale in California.” The DELTA 3 is a typical 1 kWh battery; the F3800 is the class of battery that can feed a home’s circuits through a transfer switch, which Anker sells as a separate bundle. 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 cycled ten times a year for ten years costs about $8 per kilowatt-hour at its list price, before the electricity, once you count the box itself. A generator used that little costs more per kilowatt-hour still.

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

Start with the generator, because its spec sheet gives enough to compute a fuel cost. 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 the U.S. average for regular gasoline at $4.354 a gallon for the week of October 5, 2026. Fuel alone, then, costs about $0.72 per kWh at full load and about $1.13 per kWh at quarter load. A 24-hour day at the quarter-load rate burns about 2.8 gallons, or about $12, 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 preliminary U.S. residential average for July 2026 was 18.31 cents per kWh. Not all of it comes back out. Jackery’s runtime formula for its own stations is “Working time = Explorer’s Watt-Hours * 0.85 / operating power of your device,” and this page borrows that 0.85 as an output allowance for every station, as this site’s sizing guide does; the guide calls 85 percent the friendly case. Divide 18.31 by 0.85 and grid electricity costs at least about 21.5 cents per delivered kWh, about a third of the generator’s full-load case and a fifth of its quarter-load case. Losses while charging from the wall are extra, and the allowance does not count them.

The second cost is the battery itself, and this is the number nobody on either side puts in a table. EcoFlow’s marketing copy gives the DELTA 3 “4000 cycles to 80% capacity,” and the page lists it at $699, on sale for $599. The math here uses the list price, because the sale price moves. If you really did use all 4,000 cycles, 4,000 times 1.024 kWh is at most about 4,100 kWh stored over the battery’s life (less in practice, since capacity fades toward 80% along the way), 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 fuel cost per kWh is the same on its first outage and its hundredth. The battery’s total 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.

The generator’s box can be put through the same rare-use test. Spread over the same 87 kWh in ten years, the Honda’s $1,199 price comes to about $14 per kWh before fuel, so at that level of use both boxes cost far more than the energy that passes through them. What cannot be computed is a lifetime figure to set beside the battery’s 4,000 cycles, because Honda does not publish a service life in hours for the EU2200i.

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 sizing guide’s 4 kWh figure for three days is the fridge alone; this load adds internet around the clock and a CPAP.) A fully charged DELTA 3’s 1,024 Wh covers about nine hours of that day. The F3800’s 3,840 Wh, about 3,260 Wh at the 0.85 allowance, 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 $37 in fuel for the three days, with the tank refilled every eight hours, including at night, and 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 discontinued RIVER Max, rated “600W (Surge 1200W),” may not start that fridge, 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,” and EcoFlow’s marketing calls its operation “Completely imperceptible under 600W, blending with natural ambient noise (30 dB).” 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. Among engine-driven tools (EDTs) that cause non-fire CO poisoning, it added, portable generators lead, accounting “for over 90 percent of the 900 reported fatalities associated with all EDTs during the period 2011 to 2021.”

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.” Both sources add rules that a storm makes hard to follow. Honda’s manual: “Do not use in the rain or snow,” and “Never operate a generator near open doors, windows, vents, or hatches.” ESFI: “Keep generators dry, do not operate when wet, and refuel when cool.” Dry, outdoors, 20 feet out and away from every door and window: finding that spot in bad weather is the real operating condition of a generator, and it is worth picturing before you buy one.

The EU2200i carries a shutoff: its 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. Honda’s manual says “The CO-MINDER cannot prevent all danger associated with or caused by carbon monoxide,” and the CPSC rule text says “an effective shutoff system alone is not sufficient to protect consumers from death and serious injury from accumulated CO.” ESFI’s advice for any home running one: “Make sure your home has carbon monoxide alarms outside each sleeping area and on every level of the home.”

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).” Its maintenance chapter adds: “The spark arrester must be serviced every 100 hours to keep it functioning as designed.” 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 for “1 to 2 months” in storage you should “Fill with fresh gasoline and add gasoline stabilizer,” for “2 months to 1 year” do the same and also “drain the carburetor float bowl,” 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, though the makers do not agree on the details. EcoFlow’s general 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).” Anker’s F3800 page says instead: “Check the battery capacity each week. If it’s below 30%, fully charge,” and “Charge the power station to 100% every 3 months.” Follow the instructions for your own unit, and remember that every runtime on this page assumes a full battery: a station stored at half charge delivers half of it, so top it up when a storm is forecast. 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 load 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 is a generator that recharges the battery, and EcoFlow sells that as a bundle: it lists a “Smart Generator 3000 (Dual Fuel)” among the DELTA 3’s options and says it “automatically replenishes power at night, ensuring constant backup without manual intervention.” Run by hand instead, a generator can work a few hours in the daytime near its rated load, where its fuel cost per kWh above is lowest, while the battery carries the night.

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 about $2,000 per 3.84 kWh it is an expensive way to pump water, and Anker notes that “The 240V output cannot be used while the device is charging via 120V AC.” A 240 V generator does the job for the price of fuel, but not the Honda in the table above, which is 120 V only; this case takes a larger 240 V model that this page does not price. Either way, a load wired into the house needs a transfer switch: Honda’s manual says “Do not connect to a building’s electrical system unless an isolation switch has been installed by a qualified electrician.”

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 fridge, the phones and the internet. A furnace fan is harder: at the 600 running watts in Honda’s sizing chart, a full DELTA 3 lasts about an hour and a half and an F3800 about five and a half hours, before any other load. The heat comes from combustion or blankets, whichever of the two 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. On energy alone, the discontinued 576 Wh RIVER Max, about 490 Wh at the 0.85 allowance, holds two miles for the Tesla and about a mile and a half for the Hyundai; the DELTA 3 holds three to four; the F3800’s 3,260 Wh holds eleven 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. That is Anker’s claim, not a carmaker’s. Tesla’s Gen 3 Mobile Connector manual does not mention power stations, and it warns “Do not connect the Mobile Connector into a power outlet that is not properly grounded,” so try it with your own car and cable before an outage, not during one.

There is a draw problem too. The Department of Energy’s charging-levels page says “Most EVs will come with a portable Level 1 cordset” and puts Level 1 at “Approximately 5 miles of range per 1 hour of charging,” a figure that “Assumes 1.9 kW charging power.” At that assumed draw the cord asks for more than the RIVER Max’s “3 x 600W AC OUTLETS” rating and more than the DELTA 3’s 1,800 W continuous output, so neither can be counted on to carry it. EcoFlow’s X-Boost mode claims “2200W (surge 3600W),” but its RIVER Max page cautions that “it’s best to test before use.” Even if a DELTA 3 held 1.9 kW, the roughly 870 Wh it delivers from a full 1,024 Wh battery at the 0.85 allowance would be gone in about half an hour.

The comparison runs the other way more usefully. An EV is a large battery on wheels, and some cars can export power from it. Hyundai’s 2021 US launch release said the Ioniq 5’s vehicle-to-load function delivers “1.9 kW peak power using a standard 120-volt outlet,” that it “is enabled using an available accessory adaptor,” and that “This function can even be used to charge a stranded EV,” “ideal for powering necessities during a power outage.” Tesla calls its version Powershare, and the next section covers which Teslas have it. If you already own one of those cars, the power station in your garage may be the car.

Can a Tesla power your house?

Some can, and the list is no longer only the Cybertruck. Tesla’s Powershare support page, as read on October 11, 2026, says: “With Powershare technology, Cybertruck, Model 3 and Model Y owners can power their homes during a power outage, or the grid during a high demand event, using energy from their vehicle.”

The catch for a Model 3 or Model Y is in the equipment list. For a home without a Powerwall, Tesla’s home battery, the page lists a Cybertruck, a “Powershare Gateway” and a “Universal Wall Connector,” and no other vehicle. For a home with a Powerwall it lists “Model 3, Model Y or Cybertruck,” the Powerwall, and “Either a Universal Wall Connector or Wall Connector 3.” The Powerwall and the Wall Connector must be on “the same Wi-Fi network” and “registered to the same site and be paired together,” and the last step is to “contact the Tesla Customer Support team to enable Powershare.” In Tesla’s words the car is there to “extend your backup duration during long outages.”

Which cars qualify depends on the order date. The page says: “By default, all Cybertruck trims ever produced and all Model 3 and Model Y vehicles ordered in the U.S. and Puerto Rico after October 1, 2026 are capable of Powershare. Some, but not all, Model 3 and Model Y vehicles produced before October 1, 2026 are also capable of Powershare.” To check an older Model 3 or Model Y, Tesla’s steps are on the touchscreen: tap the vehicle icon, then Software, then Additional Vehicle Information, and look for a Powershare Support toggle that is enabled.

Read the footnote before the table: “The above durations are estimates based on an average U.S. home energy usage of 30 kWh per day and a vehicle battery charge of 90%.” That is a whole house running normally. The fridge, internet, laptop and CPAP load worked through above is about 2.4 kWh a day, roughly a twelfth of Tesla’s assumption, and Tesla publishes no estimate for a house running only essentials.

There is a smaller route for which Tesla lists no Powerwall, and it is the one that overlaps with a power station. Tesla’s page says “You can transform your vehicle’s charge port into an outlet using a Mobile Connector and Tesla Outlet Adapter. Only the Gen 3 Mobile Connector supports Powershare functionality,” and that it needs a “Cybertruck with software version 2025.14.3 or later or Model 3 or Model Y with software version 2025.44 or later” plus a “Mobile Connector with software version 24.20 or later.” The Powershare page gives no wattage for that outlet, but Tesla’s shop listing for the Outlet Adapter does: “Specifications: 120V 20A 2.4kW max power.” That is the capacity of one 20-amp household circuit, well short of a whole house. Tesla’s listing describes the use as powering “devices like lights and laptops, and appliances like refrigerators, heaters and power tools.” The 2.4 kW is a rate of power, how much can run at once; the 2.4 kWh a day worked out above is an amount of energy, and the matching numbers are a coincidence. The listing was $80 for the adapter alone on October 11, 2026, with the Mobile Connector a separate purchase. It names the cars it fits by production month: any Cybertruck, a Model Y Performance from December 2025, a Model Y Premium from April 2026, a Model Y L Premium from September 2026, and other Model 3 and Model Y trims from a date the listing prints with a typo, apparently October 2026. That is a different line from the Powershare page’s order date and on-screen toggle, so check your car against both before buying. The listing also says “Your vehicle warranty does not cover damage caused by 3rd party bi-directional vehicle adaptors or chargers.”

Tesla also tells owners not to refill the car from a generator through that cable. The Gen 3 Mobile Connector manual says “Do not use private power generators as a power source for charging.” Three more of its rules matter in an outage. “Do not use the Mobile Connector when either you, the vehicle or the Mobile Connector is exposed to severe rain, snow, electrical storm or other inclement weather.” “Powershare will not start if the high-voltage Battery has less than 5% remaining energy.” And the cable “may affect or impair the operation of medical or implantable electronic devices,” so the manual says to check with the device’s maker before using it.

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, and under 600 Wh even at the 73.2 W peak ResMed lists, which a fully charged 1 kWh unit covers.

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 and AC charging at 1,500 W, so the generator needs to be rated above that draw; the 1,800 W Honda is.

Does a Tesla Model 3 or Model Y have Powershare?

Tesla says Model 3 and Model Y vehicles ordered in the U.S. and Puerto Rico after October 1, 2026 are capable of it, and that some earlier ones are; home backup with either car also needs a Powerwall and a Universal Wall Connector or Wall Connector 3.

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, store it the way its maker says and top it up before a forecast storm; it will cost at least about 22 cents per delivered kWh in electricity, nothing to store, and the price of the box spread over however many outages it ever sees. If your outages are measured in days, buy the generator, keep it dry and 20 feet from the house, and follow the storage table in its manual for the fuel. If you have a well, that means a 240 V generator and a transfer switch installed by an electrician. 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, a pairing EcoFlow sells as a bundle. The one thing not to do is buy the generator for the fridge-and-phones outage: at a quarter load it already burns more than 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 (22)

• 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 Maintain Your Portable Power Station for Long-Term Use
• 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)
• tesla.com Tesla Support: Tesla Powershare
• shop.tesla.com Tesla Shop: Tesla Outlet Adapter
• digitalassets.tesla.com Tesla: Gen 3 Mobile Connector Owner's Manual, North America (published 2025-02-09)