How Long Will a Power Station Last in a Blackout? I Tested 3 Sizes
I connected three portable power stations to my refrigerator, a lamp, a fan, and an iPad, then ran each one until the battery was empty. Here’s how long each lasted and what size you actually need.
01Quick Answer
If tech talk like watt-hours and inverters has you confused and you just want to know what size power station you actually need, this test is for you. I simulated a power outage, started each unit at 100%, and let it run until it died.
| Power Station | Capacity | Runtime | iPad Charge |
|---|---|---|---|
| EcoFlow RIVER 2 Max | 512Wh | 2h 40m | 0% → 65% |
| Anker SOLIX C1000 Gen 2 | 1,024Wh | 5h 49m | 0% → 100% |
| EcoFlow DELTA 3 Ultra Plus | 3,072Wh | 16h+ | 0% → 100% |
Bottom line: double the battery capacity, double the runtime. To keep a fridge running overnight, look for 2,000–3,000Wh or more.
02How the Blackout Test Worked
Each power station powered the same four essentials: my main refrigerator, a lamp, an iPad (drained to 0% before each run), and an air purifier standing in for a fan, since it draws about the same power. Every unit started at 100% and ran nonstop until it shut off.
Heads-Up: The Fridge Is the Biggest Variable
The compressor cycles on and off, and my family opened the fridge all day with the ice maker left on. That’s why starting readings ranged from 48W to 187W. Over each full test, the average load was roughly 150–165W. In a real emergency, with fewer door openings, you’ll likely get more runtime. Also expect about 80–90% of rated capacity as usable power, since some energy is lost converting DC to AC.
03EcoFlow RIVER 2 Max (512Wh): Entry-Level Backup
It started at 187W with the compressor running and estimated just 2 hours. It beat that and shut off at 2 hours 40 minutes, with the iPad at only 65%. It’s great for short outages and very portable at about 13.4 lbs. Full details are in my EcoFlow RIVER 2 Max review.
What I Love
- Lightest and most portable
- One-hour wall recharge
- Most affordable entry point
What Could Be Better
- Under 3 hours with a fridge
- 500W limits appliances
- Not expandable
Best for: Apartments, short outages, device charging, CPAP backup, and camping.
04Anker SOLIX C1000 Gen 2 (1,024Wh): Best for Most People
With the fridge between cycles, it showed just 48W and estimated 17 hours. It actually lasted 5 hours 49 minutes, almost exactly double the RIVER 2 Max, and fully charged the iPad. Its 2,000W inverter runs most things in your home. Read my Anker SOLIX C1000 Gen 2 review.
*UltraFast charging must be enabled in the Anker app.
What I Love
- Nearly 6 hours of runtime
- Runs most household appliances
- 49-minute recharge
What Could Be Better
- Won’t run a fridge overnight
- Not expandable
Best for: Most households, short outages, camping, and RV trips.
05EcoFlow DELTA 3 Ultra Plus (3,072Wh): Overnight Home Backup
Starting at just 60W, it ran for just over 16 hours before reaching 1%, and fully charged the iPad along the way. That’s enough to keep a fridge running overnight and into the next day. It’s built for home backup, expands to about 11kWh, and works with EcoFlow Smart Generators. See my EcoFlow DELTA 3 Ultra Plus review.
What I Love
- 16+ hours with a fridge
- Handles large appliances
- Expandable for multi-day outages
What Could Be Better
- Heavy at about 74 lbs
- Costs much more
- Add-ons cost extra
Best for: Overnight fridge backup, storm-prone areas, and whole-home backup plans.
06Side-by-Side Comparison
| Spec | RIVER 2 Max | C1000 Gen 2 | DELTA 3 Ultra Plus |
|---|---|---|---|
| Capacity | 512Wh | 1,024Wh | 3,072Wh |
| Runtime | 2h 40m | 5h 49m | 16h+ |
| AC Output | 500W | 2,000W | 3,600W |
| Expandable | No | No | Yes |
| Weight | ≈13.4 lbs | ≈24.9 lbs | ≈74 lbs |
Compare more models with the WattRated power station comparison tool.
07Can a Power Station Run a Space Heater?
Don’t Buy One Just for a Space Heater
Space heaters draw 1,200–1,500W. Even the 3,072Wh DELTA 3 Ultra Plus would last only about 2 hours, and the RIVER 2 Max’s 500W inverter can’t run one at all. For winter outages, look at propane heaters rated for indoor use, and keep a working carbon monoxide detector.
08Frequently Asked Questions
How long will a 1000Wh power station run a refrigerator?
In my test, the 1,024Wh Anker SOLIX C1000 Gen 2 ran a fridge, lamp, fan, and iPad for 5 hours 49 minutes.
What size power station do I need to run a fridge overnight?
At least 2,000Wh. The 3,072Wh DELTA 3 Ultra Plus lasted just over 16 hours.
How do I estimate runtime?
Capacity (Wh) × 0.85 ÷ average load (W). For example, 1,024 × 0.85 ÷ 150 ≈ 5.8 hours, which matches my result. Don’t trust the on-screen estimate. It swung from 2 to 17 hours in my tests.
09Final Verdict
Which Power Station Should You Get?
All three handled the essentials. The difference is how long, and that comes down to capacity.
- EcoFlow RIVER 2 Max: affordable, portable backup for short outages
- Anker SOLIX C1000 Gen 2: the best balance for most households
- EcoFlow DELTA 3 Ultra Plus: overnight fridge backup and room to grow
