Find the power station size you need before you spend $500 or more
Pick your devices and how long you need power. We'll show the battery capacity (Wh) and output (W) you need, then match it to real models, so you don't overpay for capacity you won't use or buy one that can't start your fridge.
- Free, no signup, nothing stored
- Accounts for inverter losses & startup surge
- Specs checked against manufacturer pages
Portable power station calculator
Start from a scenario, then edit the watts and hours to match your own devices. The result updates as you type.
Quick picks by use
If you already know roughly what you need, start here. Each pick is the smallest unit in our comparison that comfortably covers the job.
CPAP, phones & laptops
A CPAP without a humidifier draws about 30–60 W. Around 300 Wh covers roughly one night at the low end, more with a DC cable; a heated humidifier can double or triple use.
Check price Paid linkCamping & overnight outages
About 1,000 Wh with 1,800 W output runs a fridge, router and lights overnight and can briefly power a coffee maker.
Check price Paid linkMost of a day of home essentials
About 2 kWh keeps a fridge, internet and lights going for roughly 16–20 hours. Add solar, or go to 3 kWh+, for a full day or longer.
BLUETTI Elite 200 V2 (2,074 Wh)
Check price Paid linkSide-by-side comparison
Capacity tells you how long it runs. AC output tells you what it can run. You need enough of both. Our current shortlist comes from BLUETTI's lineup, an affiliate partner. See why, and how we pick.
Three numbers that decide which one you need
How long it lasts
Energy stored. A 100 W load for 5 hours uses 500 Wh, plus 10–20% lost converting battery power to 120 V AC.
What it can run
The total load the inverter can supply at once. A 1,200 W microwave needs at least 1,200 W of output, however big the battery.
What it can start
Fridges, pumps and AC units pull 2–5× their running watts for a moment at startup. "Lifting" modes on spec sheets are for heaters and kettles, not motors.
Guides
What size power station do I need?
The formula, worked examples for CPAP, fridges and work-from-home, and an appliance wattage table.
Read the guide →Solar generators explained
How many panel watts you need, real-world sun hours by region, and charge-time math.
Read the guide →Battery backup for your home
What a portable station can and can't run in a blackout, transfer switches, and battery vs gas.
Read the guide →Frequently asked questions
Can a portable power station run a refrigerator?
Usually, yes. A modern full-size fridge uses about 1–2 kWh per day and needs a short startup surge of roughly 1,000–1,500 W. A unit with 1,000 Wh or more and at least 1,500 W continuous output (higher surge) typically runs one for about 12–20 hours. Check the energy label on your fridge for its yearly kWh and divide by 365.
How long will a 1,000 Wh power station last?
Divide the usable energy by your load. At about 85% efficiency, 1,000 Wh delivers about 850 Wh of AC power, so a constant 100 W load runs about 8.5 hours, and a 50 W CPAP runs about 17 hours. USB and 12 V DC loads waste less.
What is the difference between watts and watt-hours?
Watts (W) measure power at a given moment, like speed. Watt-hours (Wh) measure energy over time, like distance. You need enough watts to run a device and enough watt-hours to keep it running as long as you need.
Is a "solar generator" different from a power station?
Not really. "Solar generator" is a marketing name for a portable power station sold with, or able to charge from, solar panels. The battery and inverter are the same; the panels are what make it "solar."
Can I run a power station indoors?
Yes. Battery power stations produce no exhaust, so unlike gas generators they are safe to use indoors. Keep them ventilated, dry and away from heat, and follow the manufacturer's instructions.
Does this calculator guarantee runtime?
No. It uses typical device wattages and a configurable efficiency and safety margin. Real results depend on your appliances, the temperature, battery age and the specific inverter. Treat it as a planning estimate and check device labels.