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Home battery and backup power questions, answered

What people ask before buying backup power, answered from makers' data sheets, EIA household data, Ready.gov, the Consumer Product Safety Commission and OSHA. Run times are our arithmetic from those figures.

Updated . Every answer lists the sources we read it from. If we couldn't back an answer, we left the question out.

Disclosure: We may earn a commission if you buy through these links. It never changes our recommendations. How we make money.

Home wiring is a job for a licensed electrician. New circuits, outlets, transfer switches and battery connections must meet the National Electrical Code and your local rules, and many need a permit and inspection.

Is a home battery worth it without solar?

EnergySage says resiliency, backup power in an outage, is the main reason people install home storage, and that most batteries cannot back up a whole home, so you choose the circuits.

If you mainly want the fridge, lights, internet and a medical device through an outage, a plug-in power station is far cheaper: the 2 kWh Bluetti Elite 200 V2 was listed at $899 when we checked on November 14, 2026, and you plug appliances straight into it. See the next questions for run times.

Worked example

A 13.5 kWh battery at $1,130 per kWh is about $15,255. Charged from the grid, it holds about 11 hours of the average home's use (28 kWh a day), or about 4.9 days of essentials only.

Source: EnergySage: Home energy market, first half of 2026 · Home battery sizer

Run your own numbers: Home battery backup guide

Sources

How long will a home battery power my house in an outage?

Safety first. These run times assume a full battery set up to back up the circuits you want. Air conditioning, electric heat, a well pump or an EV charger drain it much faster. A home battery must be installed by a certified installer and a licensed electrician, with the permits your area requires.

To size your own: add up the daily kWh of what you want to keep running, multiply by the days of backup you want, and check the battery's continuous power rating covers everything that runs at once. The average US home's fridges use 839 kWh a year (EIA), about 2.3 kWh a day.

Hours of the average US home's use, or days of essentials, per battery
BatteryUsable energyAverage homeEssentials only
Tesla Powerwall 313.5 kWhabout 11 hoursabout 5 days
FranklinWH aPower 215 kWhabout 13 hoursabout 5.5 days
Enphase IQ Battery 10C10 kWhabout 8 hoursabout 3.5 days

Worked example

13.5 kWh ÷ 28.4 kWh a day × 24 = about 11 hours of normal use. Cut to essentials (2.75 kWh a day) and the same battery lasts about 4.9 days.

Source: U.S. Energy Information Administration: Electric sales, revenue and average price (2024 average monthly bill) · Home battery sizer

Run your own numbers: Home battery sizer

Sources

How many years does a home battery last?

For scale: 6,000 full cycles is one a day for about 16 years, and 60 MWh is 4,000 full charges of a 15 kWh battery.

Read the warranty for the exact terms: what counts as a cycle, the capacity it guarantees and whether it transfers if you sell the house.

Worked example

Enphase warrants the IQ Battery 10C for 15 years or 6,000 cycles. At one full cycle a day, 6,000 cycles ÷ 365 = about 16.4 years, so for daily cycling the 15-year limit comes first.

Source: Enphase IQ Battery 10C data sheet (PDF) · Home battery sizer

Run your own numbers: Home battery or power station? · What size battery do I need?

Sources

How long will a portable power station run a refrigerator?

Safety first. Check that the station's surge (peak) rating covers your fridge's start-up, and plug the fridge straight into the station, not through an extension cord or power strip. Keep the doors shut and a thermometer in the fridge: the USDA says to throw out perishable food that has been above 40 F for more than 2 hours.
Hours an average fridge runs on a Bluetti power station
StationCapacityContinuous outputFridge run time
Bluetti Elite 100 V21,024 Wh1,800 Wabout 9 hours
Bluetti Elite 200 V22,074 Wh2,600 Wabout 18 hours
Bluetti Elite 3003,014 Wh2,400 Wabout 27 hours

Ready.gov also says a full freezer holds its temperature for about 48 hours, and to throw out food that has reached 40 degrees or higher. Our fridge calculator lets you enter your own fridge's yearly kWh instead of the average.

Worked example

Bluetti Elite 200 V2: 2,074 Wh × 85% usable = 1,763 Wh. An average fridge draws about 96 W over a day, so 1,763 ÷ 96 = about 18 hours.

Source: Bluetti Elite 200 V2, product page (capacity and output) · Fridge run-time calculator

Run your own numbers: Fridge run-time calculator

Sources

Should I get a power station or a gas generator for outages?

The Consumer Product Safety Commission says most generator incidents reported to it involve carbon monoxide from generators used indoors or in partly enclosed spaces, and to never run one in a home, garage, basement, crawlspace or shed, even with fans or open doors and windows. Ready.gov and the CPSC both say to install battery-backed carbon monoxide alarms.

Whichever you pick, power appliances by plugging them into the unit with suitable cords, never by connecting it to a wall outlet (next question).

Worked example

A 2,074 Wh Bluetti Elite 200 V2 runs the essentials (2,749 Wh a day) for about 15 hours: 1,763 usable Wh ÷ 2,749 × 24. A generator keeps going as long as you have fuel, but it must run outdoors.

Source: Bluetti Elite 200 V2, product page (capacity and output) · Power outage backup calculator

Run your own numbers: Best portable power stations · Generator runtime and fuel cost

Sources

Can I plug a generator or power station into a wall outlet to power my house?

OSHA warns that a generator attached to a building without a properly installed transfer switch can energize wiring for great distances. Some larger power stations are built to connect to home circuits through the maker's own panel: EcoFlow, for example, says its DELTA Pro Ultra needs its Smart Home Panel 2, installed by an electrician.

Worked example

The safe way is an extension cord to each appliance. An average fridge draws about 96 W over a day, so the 1,800 W Bluetti Elite 100 V2 can run it through a cord, with no connection to your home's wiring.

Source: Bluetti Elite 100 V2, product page (capacity and output) · Power outage backup calculator

Run your own numbers: Home backup options

Sources

Can a power station run a space heater?

Safety first. Plug the heater straight into the station, never through an extension cord or power strip, which can overheat. The CPSC says to keep anything that can burn at least 3 feet away, set the heater on a level floor and never leave it running while you sleep or are out of the room. Use a heater with tip-over and overheat shutoff.
Hours a heater runs on a power station, by heater setting
StationContinuous outputAt 1,500 WAt 750 W
Bluetti Elite 30 V2 (288 Wh)600 Wcannot run itcannot run it
Bluetti Elite 100 V2 (1,024 Wh)1,800 Wabout 0.6 hoursabout 1.2 hours
Bluetti Elite 200 V2 (2,074 Wh)2,600 Wabout 1.2 hoursabout 2.4 hours
Bluetti Elite 300 (3,014 Wh)2,400 Wabout 1.7 hoursabout 3.4 hours

Run time is the station's capacity, less about 15% for inverter losses, divided by the heater's watts.

Worked example

On its 750 W low setting, a heater on the Bluetti Elite 200 V2 runs about 2.4 hours: 2,074 Wh × 85% ÷ 750 W. On 1,500 W it is half that, about 1.2 hours.

Source: Bluetti Elite 200 V2, product page (capacity and output) · Space heater cost calculator

Run your own numbers: What a space heater costs to run

Sources

More questions answered

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Estimates only. Your actual costs depend on your utility's rate plan, how and when you charge or use power, and local prices. This is general information, not electrical, financial, tax or legal advice. Safety first: follow each maker's instructions and your local codes, use certified equipment, and have a licensed professional do any wiring. See our safety notes and disclaimer.