What size portable power station do you need?

Tap what you want to keep running, then for how long. You get the battery size and the output to look for.

What do you want to keep running?

Runs all day on its own

Runs all day on its own

Runs all day on its own

Typical figures for ENERGY STAR models. Yours may differ: change them under “Your numbers”.

For how long, without recharging?

Days

Hours on the cards are per day. Planning to recharge with panels? Our plug-in solar calculator shows what they make where you live.

Your station size

battery capacity
continuous output

Where the energy goes
    Used per day
    Over the days
    Startup surge

    Your numbers

    Usable share: inverter losses and reserve, so not all of a station's rated Wh reaches your plugs. Headroom: so the station doesn't run flat out. Both are our rough estimates; the station's maker may list its own.

    Appliance figures: ENERGY STAR certified models, median per type. Updated November 5, 2026.

    How the sizer works

    1. Energy a dayWatts × hours a day for each thing you pick. Fridges and freezers cycle on and off, so they use their energy per day instead.
    2. Over the daysEnergy a day × the days you need to go without recharging.
    3. Battery capacityThat total ÷ the share of a station's rated Wh you can actually use: 85% by default.
    4. OutputThe watts of everything on at once, plus 25% headroom, so the station isn't running flat out.

    Where the numbers come from

    • Appliances: the median of every model certified by ENERGY STAR in each category, from the EPA's open product data, updated November 5, 2026. A typical model, not yours: the label on your appliance is better.
    • Our assumptions: the 85% usable share (inverter losses and the charge a station keeps in reserve) and the 25% output headroom are rough estimates, not measurements. Change them under “Your numbers” if the station's maker lists its own.
    • Fridge watts: ENERGY STAR publishes how much energy a fridge uses a day, not what it draws while its compressor runs. That's on the rating plate inside it (amps × 120 = watts), which is why the sizer asks for it.

    What changes the result most

    • The fridge and the days: a full-size fridge uses about 1.2 kWh a day, so every extra day adds that much battery.
    • Air conditioning: a small window unit draws about 517 W while it cools, more than everything else on the list together.
    • Startup surge: anything with a compressor needs a station that can handle a brief extra draw when it starts. Check the station's surge rating and whether its maker lists that appliance.
    • Recharging: panels refill the battery during the day, so you may need less of it. See what they make where you live with the plug-in solar calculator.

    Using it for a CPAP or another medical device? Use the device maker's figures and ask your supplier about backup power before you rely on a station. For anything beyond plugging in, call a licensed electrician.

    The typical figures

    ApplianceTypicalModelsHow we got it
    Fridge (full-size, freestanding)1,241 Wh a day2,539Median annual energy use ÷ 365
    Mini fridge (compact, freestanding)671 Wh a day1,865Median annual energy use ÷ 365
    Freezer (full-size, upright and chest)1,200 Wh a day516Median annual energy use ÷ 365
    TV (50 to 55 inch screens)85 W32Median on-mode power
    Monitor (23 to 27 inch monitors)14 W1,038Median on-mode power
    Laptop (notebooks)65 W1,080Median charger's rated output, the most it can draw (real use is usually lower)
    Ceiling fan (standard ceiling fans)31 W1,201Median power at high speed
    LED light (recessed LED downlights)13 W3,237Median input power
    Window AC (window units, 5,000 to 8,000 BTU/h)517 W169Median cooling capacity ÷ efficiency (CEER), an estimate of the draw while cooling
    Dehumidifier (portable)289 W547Median water removed per day ÷ efficiency, spread over 24 hours: an estimate of the draw while running

    Plug-in solar guides

    Sources

    1. ENERGY STAR Certified Residential Refrigerators (product data) (Source, US Environmental Protection Agency, ENERGY STAR, 2026)
    2. ENERGY STAR Certified Residential Freezers (product data) (Source, US Environmental Protection Agency, ENERGY STAR, 2026)
    3. ENERGY STAR Certified Televisions (product data) (Source, US Environmental Protection Agency, ENERGY STAR, 2026)
    4. ENERGY STAR Certified Displays (product data) (Source, US Environmental Protection Agency, ENERGY STAR, 2026)
    5. ENERGY STAR Certified Computers (product data) (Source, US Environmental Protection Agency, ENERGY STAR, 2026)
    6. ENERGY STAR Certified Ceiling Fans (product data) (Source, US Environmental Protection Agency, ENERGY STAR, 2026)
    7. ENERGY STAR Certified Light Fixtures - Downlights (product data) (Source, US Environmental Protection Agency, ENERGY STAR, 2026)
    8. ENERGY STAR Certified Room Air Conditioners (product data) (Source, US Environmental Protection Agency, ENERGY STAR, 2026)
    9. ENERGY STAR Certified Dehumidifiers (product data) (Source, US Environmental Protection Agency, ENERGY STAR, 2026)

    An estimate, not a recommendation of a specific product: real use depends on your appliances, how you use them and the station. This tool is general information, not electrical advice. Safety disclaimer