List what you need to keep running and for how many days. We work out the capacity and output you need, then show which popular power stations can handle it, smallest first.
What do you need to run, and for how long each day?
Days of backup without recharging
Half a day? Enter 0.5.
Daily use
2,115 Wh
Capacity needed
2,489 Wh
rated, before losses
Output needed
217 W
everything on at once
Surge-safe output
845 W
to start motors without tripping
2,115 Wh/day × 1 day ÷ 85% AC efficiency = 2,489 Wh. Most stations briefly handle about 1.5× their rated output when a motor starts.
These cover most of your plan for less money. Running the fridge or freezer in shifts (an hour or two on, a few hours off) or adding a solar panel closes the gap.
Manufacturer specs. Confirm current figures on the brand's site before buying.
How the calculator picks a power station
A power station has to pass three checks for your plan:
Enough capacity. Your daily watt-hours × days of backup ÷ 0.85 (AC losses).
Enough output. Its continuous rating must cover everything running at once.
Survives startup surges. Running watts plus the biggest motor's extra startup surge, which most stations handle up to about 1.5× their rating.
capacity needed (Wh) = daily Wh × days ÷ 0.85
Stations that pass are listed smallest first, because the smallest one that fits is usually the best value. Those that only miss on startup surge are included with a warning, because many handle short surges above their rating.
Tips for choosing
Be honest about hours. A fridge runs 24 hours a day, but phones only charge for 2–3 hours. Hours per day matter as much as watts.
Leave heat out. Space heaters, kettles and hair dryers use as much in an hour as a fridge does in a day. Keep them off the list unless you're buying a very large station.
Add 10–20% headroom. Batteries lose capacity with age and in the cold.
Check one model in depth. Each power station has its own page with runtimes for 40+ appliances: see power stations by model.
What size power station do I need to run a refrigerator?+
For one day, at least 1,700 Wh, or about 2,000 Wh to leave some headroom, with 800 W or more of output. A typical fridge uses around 1.4 kWh a day, and the extra covers inverter losses. The output matters as much as capacity: a fridge compressor can draw over 1,000 W for a moment as it starts.
Why do I need more Wh than my appliances use?+
Power stations lose energy turning battery power into household AC. Plan on getting about 85% of the rated capacity out of the AC outlets, so we divide your daily use by 0.85.
What does 'startup surge may trip it' mean?+
Motors in fridges, freezers, pumps and air conditioners draw several times their running watts for a split second when they start. Most power stations tolerate brief surges up to about 1.5× their rated output. Beyond that, the station may shut off. Check the surge or peak figure in the manual, and start big motor loads one at a time.
Is it better to buy a bigger station or add solar?+
If outages in your area last a day or less, size for one day and skip solar. For longer outages, a mid-size station plus solar panels that refill it each day is usually cheaper than a station big enough for several days on its own. Check how fast panels refill it with the solar recharge time calculator.
My power station isn't in the list. Can I still check it?+
Yes. Compare its capacity (Wh) and continuous output (W) with the numbers this calculator gives you, or enter them in the power station runtime calculator.